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i
EVALUATION OF PURPUREOCILLIUM LILACINUM AND
GLOMUS ON PLANT GROWTH AND CONTROL OF
MELOIDOGYNE INCOGNITA OF EGGPLANT
IN ARSENIC CONTAMINATED SOIL
KHALID HASAN
DEPARTMENT OF PLANT PATHOLOGY
SHER-E-BANGLA AGRICULTURAL UNIVERSITY
DHAKA-1207
JUNE, 2015
ii
EVALUATION OF PURPUREOCILLIUM LILACINUM AND
GLOMUS ON PLANT GROWTH AND CONTROL OF
MELOIDOGYNE INCOGNITA OF EGGPLANT
IN ARSENIC CONTAMINATED SOIL
BY
KHALID HASAN
REG. NO. 09-03598
A Thesis
Submitted to
The Department of Plant Pathology, Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka,
in partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE
IN
PLANT PATHOLOGY
SEMESTER: JAN-JUN, 2015
APPROVED BY:
(Dr. F. M. Aminuzzaman)
Professor
Department of Plant Pathology
Sher-e-Bangla Agricultural University
Supervisor
(Dr. M. Salahuddin M. Chowdhury)
Professor
Department of Plant Pathology
Sher-e-Bangla Agricultural University
Co-Supervisor
(Dr. Md. Belal Hossain)
Associate professor
Chairman
Examination Committee
Department of Plant Pathology
Sher-e-Bangla Agricultural University, Dhaka
iii
CERTIFICATE
This is to certify that the thesis entitled, “EVALUATION OF
PURPUREOCILLIUM LILACINUM AND GLOMUS ON PLANT GROWTH
AND CONTROL OF MELOIDOGYNE INCOGNITA OF EGGPLANT IN
ARSENIC CONTAMINATED SOIL” submitted to the Department of Plant
Pathology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka,
in the partial fulfillment of the requirements for the degree of MASTER OF
SCIENCE (M. S.) IN PLANT PATHOLOGY, embodies the result of a piece of
bonafide research work carried out by KHALID HASAN bearing Registration No.
09-03598 under my supervision and guidance. No part of the thesis has been
submitted for any other degree or diploma.
I further certify that such help or source of information, as has been availed of during
the course of this investigation has duly been acknowledged.
Dated:
Place: Dhaka, Bangladesh
(Dr. F. M. Aminuzzaman)
Professor
Department of Plant Pathology
Sher-e-Bangla Agricultural University
Supervisor
Department of Plant Pathology Fax: +88029112649
Sher - e - Bangla Agricultural Universit y Web site: www.sau.edu.bd
Dhaka - 1207 , Bangladesh
iv
LIST OF ABBREVIATED TERMS
ABBREVIATION FULL WORD
AMF Arbuscular Micorrhizal Fungi
As Arsenic
et al. And others
BARI Bangladesh Agricultural Research
Institute
Cm3 Centimeter cube
Cm2 Centimeter square
Cm Centimeter
µgcm-2 Microgram/cm2
CV. Cultivar
oC Degree centigrade
Etc. Etcetera
Ed. Edited
Eds. Edition
G Gram
J. Journal
No. Number
PDA Potato Dextrose Agar
LSD Least Significant Difference
DMRT Duncan’s New Multiple Range Test
% Percent
RCBD Randomized Completely Block Design
Res. Research
SAU Sher-e-Bangla Agricultural University
Viz. Namely
ppb Parts per billion
v
ACKNOWLEDGEMENTS
First of all, I would like to submit my gratitude to Almighty Allah, the most
merciful and compassionate. The most Gracious and beneficent to whom every
admire is due and to his Prophet Muhammad (SM) who is perpetually a set on
fire of knowledge and leadership for humanity as a whole with whom delighting
the present endeavor has been beautiful.
Now I would like to give inexpressible gratefulness to my commendable supervisor
Dr. F. M. Aminuzzaman, Professor, Department of Plant Pathology, Sher-e-
Bangla Agricultural University, Dhaka. I am obliged to his ever inspirational
direction, studious comments, constructive suggestions and well-mannered
behavior right through the course of my study.
I express my especial thanks to my esteemed Co- Supervisor, Dr. M. Salahuddin
M. Chowdhury, Professor, Department of Plant Pathology, Sher-e-Bangla
Agricultural University, Dhaka, for his correct direction, inspirational
collaboration and support during the research work and preparation of thesis.
I am decidedly express my thanks to my honorable teachers Professor Mrs. Nasim
Akhtar, Dr. Md. Rafiqul Islam, Dr. Nazneen Sultana, Assoc. Prof. Khadija
Akhter, Dr. Nazmoon Naher Tonu, Dr. Md. Belal Hossain, Abu Noman Faruq
Ahmmed, Asstt. Prof. Shukti Rani Chowdhury, Md. Ziaur Rahman Bhuiya,
Department of Plant Pathology and Professor Dr. Md. Razzab Ali, Department of
Entomology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, for
their valuable teaching, direct and indirect suggestion and encouragement and
support during the whole study period.
vi
I am impressed to thank all stuffs and employees of Plant Pathology Department
and all farm labors of Sher-e-Bangla Agricultural University, Dhaka for their
valuable and sincere help in carrying out the research work.
I also express my especial thanks to my well-wishers and friends Amit Kumar,
Md. Abdullah-Al-Mamun, Md. Mahabub Elahi, Md. Mostaqur Rahman, Babul
Akhter, Afrin Akter Faria, Kollol, Shimul, Sanjida, Nitu and Shammi for their
help and support during my work.
I found no words to thanks my parents, brother, brother-in-law and my sister for
their unquantifiable love and constant support, their sacrifice never ending
affection, immense strength and untiring efforts for bringing my dream to proper
shape. They were constant source of inspiration, zeal and enthusiasm in the
critical moment of my studies.
The Author
vii
CONTENTS
CHAPTER TITLE PAGE
LIST OF ABBREVIATED TERMS iv
ACKNOWLEDGEMENTS v- vi
LIST OF CONTENTS vii-xi
LIST OF TABLES xii
LIST OF PHOTOGRAPHS Xiii
LIST OF FIGURES xiv-xvi
LIST OF PLATES xvii
ABSTRACT xviii
1. INTRODUCTION 1-3
2. REVIEW OF LITERATURE 4-34
2.1 Role of AMF in different crops 4-11
2.2 Interaction of arsenic and AMF 13-18
2.3 Interaction of AMF and nematode 19-27
2.4 Interaction of P. lilacinum and M. incognita 28-34
3. MATERIALS AND METHODS 35-42
3.1. Experimental site and experimental period 35
3.2. Environment of experiments 35
3.3. Pot Experiment 35
3.3.1. Crop variety used 35
3.3.2. Collection of seeds 35
viii
CONTENTS (cont’d)
CHAPTER TITLE PAGE
3.3.3. Soil collection and sterilization 35
3.4. Raising of seedling 36
3.5. Preparation of pots 37
3.6. Treatments and design of the experiment 38
3.6.1. Treatments 38
3.6.2. Design of the experiment 38
3.7. Isolation, identification and culturing of AMF 39
3.8. Fungal Isolate 43
3.8.1. Culture, mass production and harvesting of
Purpureocillium lilacinum
43
3.9. Nematode inoculum preparation 45
3.10. Preparation of arsenic solution 47
3.11. General inoculation procedure for the experiment 47
3.12. Intercultural operations 47
3.13. Harvesting and data recording 48
3.14. Data recorded 49
3.14.1. Plant data 49
3.15. Counting of nematode egg masses/root system 51
3.16 Slide preparation and counting of eggs/egg mass 53
3.17 Extraction of nematode from soil and counting of
juveniles
53
ix
CONTENTS (cont’d)
CHAPTER TITLE PAGE
3.18. Gall index 56
3.19. Egg masses colonization (%) by Purpureocillium lilacinum 57
3.20. Soil colonization by Purpureocillium lilacinum (CFUg-1 soil) 58
3.21. Observation of roots for mycorrhizal infection 59
3.22. Study of spore population in soil 60
3.23. Chemical analysis of plant sample 61
3.23.1. Nutrient analysis 61
3.23.2. Preparation of plant sample 61
3.23.3. Digestion of plant samples with nitric-perchloric acid mixture 61
3.23.4. Phosphorus 61
3.23.5. Potassium 61
3.23.6. Nitrogen 62
3.23.7. Arsenic 62
3.24. Analysis of data 62
4. RESULTS AND DISCUSSION 63-106
4.1. For all treatment combination 63
4.1.1. Shoot length 63
4.1.2. Root length 64
4.1.3. Shoot fresh weight 67
4.1.4. Root fresh weight 67
x
CONTENTS (cont’d)
CHAPTER TITLE PAGE
4.1.5. Shoot dry weight 67
4.1.6. Root dry weight 68
4.1.7. Leaf area 68
4.1.8. Chlorophyll content 69
4.2. For Glomus sp. involved treatment combination 73
4.2.1. Shoot length 73
4.2.2. Root length 75
4.2.3. Leaf area 76
4.2.4. Chlorophyll content 78
4.2.5. Shoot fresh weight 79
4.2.6. Shoot dry weight 80
4.2.7. Root fresh weight 81
4.2.8. Root dry weight 82
4.2.9. Number of spore/10 g soil 83
4.2.10. Root infection 84
4.3. For Purpureocillium lilacinum treatments 85
4.3.1. Shoot length 85
4.3.2. Root length 86
4.3.3. Leaf area 87
4.3.4. Chlorophyll content 88
xi
CONTENTS (cont’d)
CHAPTER TITLE PAGE
4.3.5. Shoot fresh weight 89
4.3.6. Shoot dry weight 90
4.3.7. Root fresh weight 91
4.3.8. Root dry weight 92
4.3.9. CFU/g soil 93
4.4.1. Gall index 94
4.4.2. Number of eggmass/ root 95
4.4.3. Number of egg/ eggmass 96
4.4.4. Eggmass colonization 97
4.4.5. Reproduction factor 98
4.5. For Meloidogyne incognita involved treatments 99
4.5.1. Number of eggmass/root 99
4.5.2. Gall index 100
4.5.3. Number of egg/ eggmass 101
4.5.4. Reproduction factor 102
4.5.5. Nutrient uptake 103-105
4.5.6. Arsenic uptake 106
5. SUMMARY AND CONCLUSION 107-109
REFERENCES 110-129
xii
LIST OF TABLES
SL.
NO.
TITLE PAGE
1. Physicochemical characteristics of pot soil
37
2. Influence of Purpureocillium lilacinum in combination
with Glomus sp. on shoot length, root length, shoot and
root fresh weight of eggplant in arsenic amended soil
challenged with Meloidogyne incognita
66
3. Influence of Purpureocillium lilacinum in combination
with Glomus sp. on dry weight of shoot and root, leaf area
and chlorophyll content of eggplant in arsenic amended
soil challenged with Meloidogyne incognita
69
4. Influence of Purpureocillium lilacinum in combination
with Glomus sp. on phosphorus, potassium and Sulphur
percentage of shoot of eggplant in arsenic amended soil
challenged with Meloidogyne incognita
104
xiii
LIST OF PHOTOGRAPHS
SL.
NO.
TITLE PAGE
1 Raising of eggplant seedling 36
2 Identification of Glomus sp. 40
3 Confirmation of colonization observing vesicle inside
the cell of Cassia tora
40
4 Inoculation of Glomus spore on maize seed 41
5 Inoculation of Glomus spore in maize root 41
6 Mass culture of Glomus sp. with trap plant maize 42
7 Pure culture of P. lilacinum on PDA media 44
8 Mass culture of P. lilacinum on chick pea 44
9 M. incognita inoculum production in association with eggplant root 46
10 M. incognita infected root showing eggmass and gall 46
11 Leaf area measurement by CI-202 Portable Laser Leaf Area Meter 50
12 Measurement of chlorophyll content of eggplant
leaf by SPAD 502 Plus Chlorophyll Meter
50
13 Heavily galled root treated with Phloxine-B solution 52
14 Phloxine-B treated root for counting of eggmass/ root 52
15 Counting the number of egg/ eggmass 54
16 Extraction of nematode by Bangladeshi plate method (modified
White Head and Heaming method, 1965)
54
17 Second stage juveniles of Meloidogyne incognita 55
18 Determination of CFUg-1 soil using the soil dilution plate method 58
19 Different growth pattern of eggplant in different treatment
combination during two months of growing
71
xiv
LIST OF FIGURES
SL.
NO.
TITLE PAGE
1 Shoot length of eggplant influenced by the eight mycorrhizal
treatments in different combination of P. lilacinum, M. incognita
and arsenic
72
2 Represents the root length of eggplant influenced by the eight
mycorrhizal treatments with different combination of P. lilacinum,
M. incognita and arsenic
73
3 The role of Glomus sp. on leaf area of eggplant in combination of
P. lilacinum in arsenic amended soil challenged with Meloidogyne
incognita
74
4 Chlorophyll content of eggplant influenced by Glomus sp in
combination of P. lilacinum in arsenic amended soil challenged
with Meloidogyne incognita
75
5 Variation of shoot fresh weight of eggplant due to eight
mycorrhizal treatments of eggplant influenced by Glomus sp. in
combination of P. lilacinum in arsenic amended soil challenged
with Meloidogyne incognita
76
6 Shoot dry weight of eggplant influenced by Glomus sp. in
combination of P. lilacinum in arsenic amended soil challenged
with Meloidogyne incognita
77
7 Root fresh weight of eggplant influenced by Glomus sp. in
combination of P. lilacinum in arsenic amended soil challenged
with Meloidogyne incognita
78
8 Shoot dry weight of eggplant influenced by Glomus sp. in
combination of P. lilacinum in arsenic amended soil challenged
with Meloidogyne incognita
79
9 Number of spore/ 10 g soil influenced by Glomus sp in
combination of P. lilacinum in arsenic amended soil challenged
with Meloidogyne incognita
80
10 Root infection (%) influenced by Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne
incognita
81
xv
LIST OF FIGURES (cont’d)
SL.
NO.
TITLE PAGE
11 Shoot length of eggplant influenced by the eight P. lilacinum
involved treatments in different combination with Glomus sp., M.
incognita and arsenic
82
12 Root length of eggplant influenced by the eight P. lilacinum
treatments with different combination of Glomus sp., M. incognita
and arsenic
83
13 The role of P. lilacinum involved treatments on leaf area of
eggplant in combination of Glomus sp in arsenic amended soil
challenged with Meloidogyne incognita
84
14 Chlorophyll content of eggplant influenced by the role of eight P.
lilacinum treatments in combination of Glomus sp. in arsenic
amended soil challenged with Meloidogyne incognita
85
15 Variation of shoot fresh weight of eggplant due to eight P.
lilacinum treatments of eggplant influenced by the role of P.
lilacinum in combination of Glomus sp. in arsenic amended soil
challenged with Meloidogyne incognita
86
16 Shoot dry weight of eggplant influenced by P. lilacinum involved
treatments in combination of Glomus sp. in arsenic amended soil
challenged with Meloidogyne incognita
87
17 Root fresh weight of eggplant influenced by P. lilacinum involved
treatments in combination of Glomus sp in arsenic amended soil
challenged with Meloidogyne incognita
88
18 Root dry weight of eggplant influenced by P. lilacinum involved
treatments in combination of Glomus sp. in arsenic amended soil
challenged with Meloidogyne incognita
89
19 Influence of P. lilacinum in different combination with Glomus sp.
in arsenic amended soil challenged with Meloidogyne incognita
on CFU/ g soil
90
20 Gall index of eggplant influenced by P. lilacinum 91
21 Role of P. lilacinum on the number of eggmass/ root 92
22 Effect of P. lilacinum on the number of M. incognita egg/ eggmass 93
xvi
LIST OF FIGURES (cont’d)
SL.
NO.
TITLE PAGE
23 Role of P. lilacinum on of eggmass colonization by bioagent 94
24 Role of P. lilacinum on of reproduction factor of M. incognita 95
25 Number of eggmass/ root of M. incognita influenced by Glomus
sp. in combination of P. lilacinum in arsenic amended soil
96
26 Gall index of eggplant influenced by P. lilacinum and Glomus sp.
in arsenic amended soil challenged with Meloidogyne incognita
97
27 Number of egg/ eggmass of M. incognita on different combination
with P. lilacinum and Glomus sp. in arsenic amended soil
challenged with Meloidogyne incognita
98
28 Reproduction factor of M. incognita influenced by Glomus sp in
combination of P. lilacinum in arsenic amended soil
99
29 Arsenic uptake by shoot of eggplant influenced by Glomus sp in
combination of P. lilacinum in arsenic amended soil challenged
with Meloidogyne incognita
104
xvii
LIST OF PLATES
SL.
NO.
TITLE PAGE
1 Egg colonization of M. incognita by P. lilacinum 57
2 Observation of eggplant roots for mycorrhizal infection 60
3 Eggplant root at different treatments combination 70
xviii
EVALUATION OF PURPUREOCILLIUM LILACINUM AND
GLOMUS ON PLANT GROWTH AND CONTROL OF
MELOIDOGYNE INCOGNITA OF EGGPLANT
IN ARSENIC CONTAMINATED SOIL
BY
KHALID HASAN
ABSTRACT
Root-knot nematode Meloidogyne incognita remarkably reduces eggplant growth
and yield in Bangladesh. Nematophagous fungus Purpureocillium lilacinum has
profound role on suppression of M. incognita. Again, contamination of groundwater
by arsenic and plant uptake from soil contaminated by groundwater or irrigation
water. AM fungi have significant effect on plant growth reducing arsenic
contamination to plant. This study determined the role of AMF (Glomus sp.)
combined with the P. lilacinum on growth of eggplant and nematode control in
arsenic amended soil challenged with M. incognita. AMF colonized root fragments
of maize seedlings and rhizosphere soil (100 g) containing spore were used for AMF
treatment in combined with P. lilacinum maintaining CFU (5x106) of P. lilacinum/g
soil mixed with 50 ppm arsenic. Eggs of M. incognita was adjusted to 10000
eggs/pots for inoculation. All growth characteristics was higher in combined
treatment of AMF (Glomus sp.) and P. lilacinum (G+Pl) inoculated plants in
comparison to the other treatments, and decreased significantly with the M.
incognita (Mi) and arsenic (As) involved treatment combination. But, M. incognita
(Mi) and arsenic (As) combined with (G), (Pl) and (G+Pl) gave better results rather
than their individual treatments. The findings of this research revealed less M.
incognita infection and arsenic content, highest leaf area, higher chlorophyll content
and nutrient uptake in (G+Pl) inoculated plants.
1
INTRODUCTION
A large area being covered with vegetable crops resulting in increased yield and thus
created a better socio-economic status for farmers in Bangladesh. The challenge now
is to grow more food of high nutritive quality. The solution lies in developing and
adopting hi-tech agriculture to improve the productivity in eco-friendly manner.
Eggplant belonging to Solanaceae family is chosen for the study, as this is a commonly
consumed vegetable in our country. Commercially it is less expensive and
economically more important. It is widely grown in Bangladesh, China, India,
Pakistan and Philippines. It is also popular in others countries like Balkan area,
France, Indonesia, Italy, Japan, Mediterranean, Turkey and United states (Bose and
Som, 1986). It is well-known as “Begoon” (Eggplant) in Bangladesh, is a very
common and favorite vegetable. It is grown in an area of about 1,15,424 acres
producing about 341262 Mt of fruits where 44,377 acres in Kharif season and 71,047
acres in Rabi season of the year with total annual production of 3,41,262 M. Tons and
the average yield is 5.86 t/ha in 2009-2010 (BBS, 2011). The yield potential of
eggplant is low in Bangladesh compared to other countries. Incidence of insects, pests
and diseases generally hampered the production of eggplant. This crop suffers from
the various diseases; about 13 different diseases so far recorded in Bangladesh (Das
et al. 2000; Rashid, 2000). Among those diseases, root knot of eggplant has been
treated as one of the major constraints in eggplant cultivation in Bangladesh. Root
knot nematodes are plant parasitic organism of the genus Meloidogyne spp. About
2000 plants are susceptible to infection by root knot nematodes Meloidogyne spp.
Root knot is widely distributed important diseases in the country (Talukdar, 1974;
Ahmed and Hossain, 1985). In Bangladesh root knot may cause as much 27.2% loss
in fruit yield of eggplant (BARI, 2001). Eggplant cultivation in Bangladesh is severely
impaired by three important wilt causing pathogens viz. Ralstonia solanacearum,
Fusarium oxysporum and Meloidogyne spp. the causal agent of Bacterial wilt,
2
Fusarium wilt and Nemic wilt, respectively and caused considerable damage of
eggplant (Talukdar, 1974; Ahmed and Hossain, 1985; Ali et al., 1994). These are also
the major limiting factors for eggplant production throughout the world (Hinata,
1986). Infection of roots by nematodes alter uptake of water and nutrients and
interferes with the translocation of minerals and photosynthesis (Williamson and
Hussey, 1996). Such alterations change the shoot and root ratio (Anwar and Van
Gundy, 1989) and expose the plant to other pathogens. For example, nematode root
infection increases the incidence and severity of Fusarium wilt diseases on a variety
of crops (Martin et al., 1994), which can negatively influence yield (Orr and Robison,
1984). Vegetable yield reductions have reached as high as 30% for susceptible
genotypes in the presence of plant parasitic nematodes in some production areas
(Anwar et al., 2009a). The control of plant parasitic nematode is a difficult task has
mainly depended on chemical nematicide for remarkable reduction of nematode
population has been achieved (Jatala,1985). Biocontrol seems to be the most relevant
and practically damaging approach for the control of root knot nematode is an
excellent biocontrol agent in tropical and subtropical agricultural soils.
Purpureocillium lilacinum has been reported to reduce nematode population densities
and is considered as one of the most promising practiciable biocontrol agent for the
management of plant parasitic nematodes (Jatala., 1986; Siddiki et al., 2000; Eapen et
al., 2005; Atkins et al., 2005; Kiewnick et al., 2011). A pre-planting soil treatment
reduced root galling by 66% egg masses by 74% and the final nematode population
in the roots by 71% compared to the inoculated control (Kiewnick et al., 2006). It is
now recognized that AM fungi can be harnessed in order to improve productivity in
agriculture, fruit culture, and forestry by reducing the input of fertilizers and/or by
enhancing plant survival, thus offsetting ecological and environmental concerns. For
this reason, studies on mycorrhizae gained importance due to its practical use as a low
input technology for managing soil fertility and plant nutrition. Cofcewicz et al.
(2001) under greenhouse conditions studied the interaction of arbuscular mycorrhizal
fungi Glomus etunicatum and Gigaspora margarita and root knot nematode,
3
Meloidogyne javanica and their effects on the growth and mineral nutrition of tomato.
The result pointed out that the shoot dry matter yield was reduced by nematode
infection and this reduction was less pronounced in plants colonized with G.
etunicatum than plant colonized with G. margarita and non-mycorrhizal plants.
Arbuscular mycorrhizae (AM) are the most common mycorrhizal form and formed
arbuscules (Agrios, 1988). Arbuscular mycorrhizal fungi (AMF), as an important
group of soil fungi, can form symbiotic associations with more than 80% of the land
plant families (Schwarzott et al., 2001). AMF can essentially improve plant mineral
nutrition and plant water relations and enhance plant resistance to heavy metal
contaminations (Hildebrandt et al., 2007). Recent studies show that the arbuscular
mycorrhizas naturally occur in As-contaminated soils (Smith et al., 2010) and
mycorrhizal inoculation can improve the As tolerance of tomato (Liu et al., 2005b),
maize (Bai et al., 2008). For the better efficacy in eco-friendly management of
nematode and mitigating arsenic problem soil during vegetable production in arsenic
polluted area of Bangladesh, evaluation of Purpureocillium lilacinum in combination
with Arbuscular Mycorrhizal Fungus (Glomus sp.) on plant growth and suppression
of Meloidogyne incognita on eggplant in arsenic amended soil is an endeavor to find
out the following objectives.
Objectives:
1. To study the effect of Purpureocillium lilacinum either alone or in combination
with Mycorrhizal fungus (Glomus sp.) on plant growth and suppression of root knot
nematode Meloidogyne incognita on eggplant in arsenic amended soil.
2. To determine the effect of fungal antagonist P. lilacinum either alone or in
combination with Arbuscular Mycorrhizal fungus on nutrient uptake and reducing
arsenic toxicity of eggplant in arsenic amended soil.
4
REVIEW OF LITERATURE
2.1. Role of AMF in different crops
Priyadharsini et al. (2015) proposed that most of the agricultural and
horticultural crops are associated with common soil fungi, the arbuscular mycorrhizal
(AM) fungi. These fungi are crucial for plant health and fitness as they increase the
efficiencies of the plant root systems. The hyphae of these fungi originating from roots
grow into the soil and absorb nutrients especially phosphorus and deliver it to the
roots. They also play a crucial role in imparting tolerance to plants against various
stresses as well as modifying soil structure.
Caporale et al. (2014) investigated the effect of arbuscular mycorrhizal fungi
(AMF - Glomus spp.) on the growth of the vetiver grass (Chrysopogon zizanioides L.)
and its As uptake from contaminated hydroponic and soil systems. An ameliorative
effect of the AMF inoculation in enhancing plants growth was found, mainly by
stimulating the development of their root system. In addition, AMF-inoculated plants
also took up more As from both contaminated systems compared to non-inoculated
plants, although the differences were not always statistically significant (p < 0.05).
Kelkar et al. (2013) carried out this experiment where soils with different
concentrations of arsenic with and without mycorrhizal inoculums were tested in
Trigonella foenumgraceum. The response of mycorrhiza in T. foenumgraceum was
determined in terms of percentage germination of seeds, sustainability of seedlings,
fresh weight and dry weight of plants etc. It was observed that in the pot soil
contaminated with arsenic and no mycorrhizal inoculum, performance was very bad
in terms of all aspects of growth, whereas in the pot where mycorrhizal inoculum was
added along with contaminated soil, the performance of the plant was better.
5
Beltrano et al. (2013) conducted a study in a greenhouse, to investigate the
effects of arbuscular mycorrhizal fungi (Glomus intraradices), soil salinity and P
availability on growth (leaf area and dry weight), nutrient absorption and ion leakage,
chlorophyll, soluble sugar and proline content and alkaline phosphatase activity of
pepper plants (Capsicum annuum L.). Plants were grown at four levels of salinity (0,
50, 100 and 200 mM NaCl) and two P levels (10 and 40 mg kg-1). Colonization was
80 to 51% in non-stressed and high salt-stressed plants, respectively. The mycorrhizal
dependency was high and only reduced at the higher salinity level. Mycorrhizal plants
maintained greater root and shoot biomass at all salinity levels compared to non-
mycorrhizal plants, regardless the P level. Interactions between salinity, phosphorous
and mycorrhizae were significant for leaf area, root and shoot dry mass. The results
indicate that the mycorrhizal inoculation is capable of alleviating the damage caused
by salt stress conditions on pepper plants, to maintaining the membranes stability and
plant growth, and this could be related to P nutrition.
Abdullahi et al. (2013) conducted a field experiment to determine the effect of
arbuscular mycorrhizal fungi (AMF) in reducing the excessive amount of chemical
fertilizer used in cultivation of onion. Inoculated and un-inoculated onion plant were
grown with varying levels of N and P fertilizer (00-00, 40-20, 60-30, 80-40, 100-50
and 120-60 kg ha-1 N and P, respectively), K was constant at 50 kg ha-1 laid out in
randomized complete block design with 3 replications. Mycorrhizal colonization (%),
plant height (cm), number of leaves per plant, fresh and dry shoot biomass (g), and N,
P, and K concentrations in plant were determined. The results showed no significant
difference in plant height and number of leaves per plant between inoculated and un-
inoculated plants at 4 weeks after transplant (WAT) for all treatments. Inoculated
plants with 60-30-50 kg ha-1 NPK produced plants with highest growth parameters
(38.63 cm, 13.66, 27.80g and 3.74 g) for plant height, number of leaves, fresh shoot
and dry biomass, respectively as compared to un-inoculated plants with high dosages
6
(120-60-50 kg ha-1 NPK) of fertilizer. From this study, it can be concluded that using
AMF could reduce the amount of excessive chemical fertilizer needed to produce
onion.
Gomes et al. (2012) found that Anadenanthera peregrina is a Brazilian
savanna tree species that occurs naturally in arsenic (As)-contaminated areas, and it’s
As resistance has been associated with arbuscular mycorrhizal fungi (AMF)
symbiosis. A plant’s ability to survive in stressful environments is correlated with its
nutrition status, which can be affected by As uptake. The present study evaluated the
influence of As on the concentrations and distribution of nutrients in the roots and
shoots of A. peregrina grown in the absence of AMF. These plants were grown in
substrates spiked with 0, 10, 50, and 100 mg As kg-1 for 25 d under greenhouse
conditions, and the concentrations of essential macro- (P, K, Ca, Mg, N, and S) and
micro- (Fe, Mn, Cu, Zn, B, and Mo) nutrients in the roots and shoots were then
determined. Enhanced As levels increased the concentrations of P, S, and N and
decreased Ca, Mg, and Fe.
Bücking et al. (2012) investigated approximately 80 % of all known land plant
species form mycorrhizal interactions with ubiquitous soil fungi. The majority of
these mycorrhizal interactions is mutually beneficial for both partners and is
characterized by a bidirectional exchange of resources across the mycorrhizal
interface. The mycorrhizal fungus provides the host plant with nutrients, such as
phosphate and nitrogen, and increases the abiotic (drought, salinity, heavy metals) and
biotic (root pathogens) stress resistance of the host. In return for their beneficial effect
on nutrient uptake, the host plant transfers between 4 and 20% of its
photosynthetically fixed carbon to the mycorrhizal fungus.
Smith et al. (2011) reviewed new findings about the roles of the arbuscular
mycorrhizas (mycorrhiza = fungus plus root) in plant growth and phosphorus (P)
7
nutrition. They focus particularly on the function of arbuscular mycorrhizal (AM)
symbioses with different outcomes for plant growth (from positive to negative) and
especially on the interplay between direct P uptake via root epidermis (including root
hairs when present) and uptake via the AM fungal pathway. The results are highly
relevant to many aspects of AM symbiosis, ranging from signaling involved in the
development of colonization and the regulation of P acquisition to the roles of AM
fungi in determining the composition of natural plant assemblages in ecological
settings and their changes with time.
Irfan et al. (2011) conducted an experiment on Solanum melongena L. a
medicinally and economically important crop plants were grown in polythene bags.
The effect of mycorrhizal inoculation (Glomus mosseae) and increasing phosphate
levels on the expression of the photosynthetic activity in terms of chlorophyll content.
Antioxidant enzymes like peroxidase, polyphenol oxidase, root acid and alkaline
phosphatase activity of Solanum melongena were evaluated. The experimental design
was entirely at CRBD with eight treatments with three levels of phosphate
(50,100,150 mg kg-1 of soil). Root colonization ranged from 50.33 to 67.33%. The
activity of the studied antioxidant enzymes was found to be increased in arbuscular
mycorrhizal (AM) Solanum plants. This work suggests that the mycorrhiza helps
Solanum plants to perform better in low and high phosphate level by enhancing
antioxidant enzyme activity, acid and alkaline phosphatase activity and total
chlorophyll content.
Aggarwal et al. (2011) reported that mycorrhizal symbiosis is a highly evolved
mutually beneficial relationship. This symbiosis confers benefits directly to the host
plant’s growth and development through the acquisition of Phosphorus (P) and other
mineral nutrients from the soil by the AMF. In addition, their function ranges from
stress alleviation to bioremediation in soils polluted with heavy metals. They may also
enhance the protection of plants against pathogens and increases the plant diversity.
8
This is achieved by the growth of AMF mycelium within the host root (intra radical)
and out into the soil (extra radical) beyond. Proper management of Arbuscular
Mycorrhizal fungi has the potential to improve the profitability and sustainability of
agricultural systems.
Ortas (2010) evaluated the effects of different arbuscular mycorrhizal fungi
(AMF) under field conditions for cucumber production. The parameters measured
were seedling survival, plant growth and yield, and root colonization. In 1998 and
1999, Glomus mosseae and Glomus etunicatum inoculated cucumber seedlings were
treated with and without P (100 kg P2O5 ha-1) application. A second experiment was
set up to evaluate the response of cucumber to the inoculation with a consortia of
indigenous mycorrhizae, G. mosseae, G. etunicatum, Glomus clarum, Glomus
caledonium and a mixture of these four species. Inoculated and control non inoculated
cucumber seedlings were established under field conditions in 1998, 2001, 2002 and
2004. Seedling quality, seedling survival under field conditions and yield response to
mycorrhiza were tested. The field experiment results showed that mycorrhiza
inoculation significantly increased cucumber seedling survival, fruit yield, P and Zn
shoot concentrations. The most relevant result for growers was the increased survival
of seedlings.
Akond et al. (2008) carried out an investigation for fifteen plant species,
cultivated widely as vegetable crops in mycorrhizal colonization in their root tissues
with a range of 7 to 98% variations in root infections and spore densities were found
statistically significant. Plant species had a significant role in root tissue colonization
by mycorrhizal fungi.
Ali (2008) reported that AMF has great influence on growth of some
agricultural crops like brinjal, tomato, okra, danta and chili. Mycorrhiza enhanced
9
disease reduction in all the selected agricultural crops and also significantly influenced
the nutrient uptake capacity of crops over control.
Van et al. (2008) explored the various roles that mycorrhizal fungi play in
sustainable farming systems with special emphasis on their contribution to crop
productivity and ecosystem functioning. A number of mechanisms and processes by
which mycorrhizal fungi can contribute to crop productivity and ecosystem
sustainability. Results showed that the significance of mycorrhizal fungi for
sustainable farming systems.
Nogueira et al. (2006) evaluated the response of Rangpur lime (Citrus limonia)
to arbuscular mycorrhiza (Glomus intraradices), under P levels ranging from low to
excessive. Plants were grown in three levels of soluble P (25, 200 and 1,000 mg kg-
1), either inoculated with Glomus intraradices or left noninoculated, evaluated at 30,
60, 90, 120 and 150 days after transplanting (DAT). Total dry weight, shoot P
concentration and specific P uptake by roots increased in mycorrhizal plants with the
doses of 25 and 200 mg kg-1 P at 90 DAT. With 1,000 mg kg-1 P, mycorrhizal plants
had a transient growth depression at 90 and 120 DAT, and non-mycorrhizal effects on
P uptake at any harvesting period. Root colonization and total external mycelium
correlated positively with shoot P concentration and total dry weight at the two lowest
P levels. Although the highest P level decreased root colonization, it did not affect
total external mycelium to the same extent.
Islam (2006) carried out an experiment on the role of arbuscular mycorrhizal
(AM) fungi on growth and nutrient uptake of some legumes. He observed growth
response was positive to AMF in all the selected legumes. The seedlings emergence,
plant height, shoot length and root length of inoculated legumes were comparatively
higher than that of uninoculated legumes.
10
Giri et al. (2005) assessed the effect of two arbuscular mycorrhizal (AM) fungi,
Glomus fasciculatum and G. macrocarpum on shoot and root dry weights and nutrient
content of Cassia tora in a semi-arid wasteland soil. Under nursery conditions
mycorrhizal inoculation improved growth of seedlings. Root and shoot dry weights
were higher in mycorrhizal than non-mycorrhizal plants. The concentration of P, K,
Cu, Zn and Na was significantly higher in AM inoculated seedlings than non-
inoculated seedlings. On transplantation to the field, the survival rate of mycorrhizal
seedlings (75-90%) was higher than that of non-mycorrhzal seedlings (40%).
Combination of AMF and Pseudomonus proved to be better. Present findings
indicated that microbial gene pool especially the key helpers for the maintenance of
soil health residing in the vicinity if roots were positively affected by using
Pseudomonus and AMF.
Karagiannidis et al. (2002) studied the effect of the arbuscular mycorrhizal
fungus (AMF) Glomus mossae and the soil borne Verticillium dahliae and their
interaction on root colonization, plant growth and nutrient uptake in eggplant and
tomato seedlings grown in pots. Root colonization by the AMF as well as spore
formation was higher (34.6% and 30.5%, respectively) in the eggplant than in tomato.
The mycrrohizal treatments increased fresh and dry weight and mean plant height in
tomato by 96, 114, and 21% compared to control.
Mridha and Xu (2001) studied the genus diversity of AMF fungi in some
vegetable crops in Bangladesh. They identified Acaulospora, Entrophosphora and
Glomus abundantly. But Gigaspora and Sclerocystis were poor in number.
George et al. (2000) reported that arbuscular mycorrhizal fungi (AMF) can
greatly affect the plant uptake of mineral nutrients. It may also protect plants from
harmful elements in soil. The contribution of AM fungi to plant nutrient uptake is
mainly due to the acquisition of nutrients by the extra-radical mycorrhizal hyphae.
Many mycorrhizal fungi can transport nitrogen, phosphorus, zinc and copper to the
11
host plant, but other nutrients can also be taken up and translocated by the hyphae.
Among the nutrients, phosphorus is often the key element for increased growth or
fitness of mycorrhizal plants because phosphorus is transported in hyphae in large
amounts compared to the plant phosphorus demand.
Dodd et al. (2000) reported AMF are primarily responsible for nutrient transfer
from soil to plant but have other roles such as soil aggregation, protection of plant
against drought stress and soil pathogens and increasing plant diversity. This is
achieved by the growth of their fungal mycelium within a host root and out into the
soil beyond. In agro- and natural ecosystems AMF are pivotal in closing nutrient
cycles and have a proven multi-functional role in soil-plant interactions.
Mridha et al. (1999) studied AM colonization in some crops of Bangladesh.
They observed high levels of colonization in the numbers of Leguminosae family and
no colonization in Amaranthaceae, Chenopodiaceae and Cruciferae.
12
2.2. Interaction of arsenic and AMF
Zhang et al. (2015) conducted two pot experiments where wild type and a non-
mycorrhizal mutant (TR25:3-1) of Medicago truncatula were grown in arsenic (As)-
contaminated soil to investigate the influences of arbuscular mycorrhizal fungi (AMF)
on As accumulation and speciation in host plants. The results indicated that the plant
biomass of M. truncatula was dramatically increased by AM symbiosis. Mycorrhizal
colonization significantly increased phosphorus concentrations and decreased As
concentrations in plants. Moreover, mycorrhizal colonization generally increased the
percentage of arsenite in total As both in shoots and roots, while dimethyl arsenic acid
(DMA) was only detected in shoots of mycorrhizal plants. The results suggested that
AMF are most likely to get involved in the methylating of inorganic As into less toxic
organic DMA and also in the reduction of arsenate to arsenite. The study allowed a
deeper insight into the As detoxification mechanisms in AM associations.
González et al. (2014) conducted research to identify the in situ localization
and speciation of arsenic (As) in the AM fungus Rhizophagus intraradices [formerly
named Glomus intraradices] exposed to arsenate [As(V)]. By using a two-
compartment in vitro fungal cultures of R. intraradices-transformed carrot roots,
micro-spectroscopic X-ray fluorescence (m-XRF), and micro spectroscopic X-ray
absorption near edge structure (m-XANES). It was observed that As(V) is absorbed
after 1 h in the hyphae of AMF. Three hours after exposure a decrease in the
concentration of As was noticed and after 24 and 72 h no detectable As concentrations
were perceived suggesting that As taken up was pumped out from the hyphae. No As
was detected within the roots or hyphae in the root compartment zone three or 45 h
after exposure. This suggests a dual protective mechanism to the plant by rapidly
excluding As from the fungus and preventing As translocation to the plant root. m-
XANES data showed that gradual As(V) reduction occurred in the AM hyphae
between 1 and 3 h after arsenic exposure and was completed after 6 h.
13
Bhalerao et al. (2013) found that arbuscular mycorrhizal (AM) Fungi provide
an attractive system to advance plant based environmental clean-up. AM associations
beingintegral functioning parts of plant roots and are widely recognized as enhancing
plant growth on severely disturbed sites, including those contaminated with heavy
metals. They are reported to play an important role in metal tolerance and
accumulation. Isolation of the indigenous and presumably stress-adapted AM fungi
can be a potential biotechnological tool for inoculation of plants for successful
restoration of degraded ecosystems.
Orłowska et al. (2012) assessed the role of indigenous and non-indigenous
arbuscular mycorrhizal fungi (AMF) on As uptake by Plantago lanceolata L. growing
on substrate originating from mine waste rich in As in a pot experiment. P. lanceolata
inoculated with AMF had higher shoot and root biomass and lower concentrations of
As in roots than the non-inoculated plants. There were significant differences in As
concentration and uptake between different AMF isolates. Inoculation with the
indigenous isolate resulted in increased transfer of As from roots to shoots; AMF from
non-polluted area apparently restricted plants from absorbing As to the tissue. The
mycorrhizal colonization affected also the concentration of Cd and Zn in roots and Pb
concentration, both in shoots and roots.
Karim et al. (2011) found that arbuscular mycorrhizal fungi (AMF) present on
the roots of plants growing on heavy metals contaminated soils and play an important
role in metal tolerance and accumulation enhancing plant growth on severely
disturbed sites, including those contaminated with heavy metals (HMs). Isolation of
the indigenous and presumably stress-adapted AMF can be a potential
biotechnological tool for inoculation of plants for successful restoration of degraded
ecosystems. Plants grown in metal contaminated sites harbor unique metal tolerant
and resistant microbial communities in their rhizosphere. These rhizomicroflora
14
secrete plant growth-promoting substances, siderophores, phytochelators to alleviate
metal toxicity, enhance the bioavailability of metals (phytoremediation) and
complexation of metals (phytostabilisation).
González et al. (2011) utilized the two-compartment system to study the effect
of arsenic (As) on the expression of the Glomus intraradices high-affinity phosphate
transporter GiPT, and the GiArsA gene, a novel protein with a possible putative role
as part of an arsenite efflux pump and similar to ArsA ATPase. Results showed that
induction of GiPT expression correlates with As (V) uptake in the extra-radical
mycelium of G. intraradices. It also showed a time-concerted induction of transcript
levels first of GiPT, followed by GiArsA, as well as the location of gene expression
using laser microdissection of these two genes not only in the extra-radical mycelium
but also in arbuscules. This work represents the first report showing the dissection of
the molecular players involved in arbuscular mycorrhizal fungus (AMF)-mediated As
tolerance in plants, and suggests that tolerance mediated by AMF may be caused by
an As exclusion mechanism, where fungal structures such as the extra-radical
mycelium and arbuscules may be playing an important role.
Elahi et al. (2010) carried out an experiment to determine the influence of AMF
inoculation on growth, nutrient uptake, arsenic toxicity and chlorophyll content of
eggplant grown in arsenic amended pot soil. Three levels of arsenic concentrations
(10ppm, 100ppm and 500ppm) were used in pot soil and eggplant was grown in
arsenic amended soils with or without mycorrhizal inoculation. Root length, shoot
height, root fresh weight, shoot fresh weight, root dry weight and shoot dry weight
were higher in AMF inoculated plants in comparison to their respective treatments
and decreased significantly with the increase of rate of arsenic concentrations. Less
arsenic content and higher chlorophyll and nutrient uptake were recorded in
mycorrhiza inoculated plants in compare to noninoculated plants. The findings of the
15
study indicated that AMF inoculation not only reduces arsenic toxicity but also can
increase growth and nutrient uptake of eggplant shoot.
Saha (2008) conducted three experiments to justify the effect of mycorrhiza on
seed germination in soil amended with different concentrations of arsenic solution.
He conducted the experiments in plastic tray, blotter plate and poly bags. Seedling
emergence, shoot height, root length, fresh and dry weight of shoot, fresh and dry
weight of root and also nutrient uptake by shoot of plants is increased in mycorrhiza
inoculated plants than that of inoculated plants.
Akhter (2008) conducted an experiment an experiment on the effect of
mycorrhizal fungi on growth and nutrient uptake by few crops in arsenic amended
soil. She found that 10 ppm arsenic solution + mycorrhiza treatment showed the
lowest performance in all the selected crops. The experiment exposed that with the
increase of arsenic concentration plants show the decrease growth performance.
Chen et al. (2007) observed that mycorrhizal fungi may play an important role
in protecting plants against arsenic contamination. They compartmented pot
cultivation system to investigate the roles of Glomus mosseae in plant P and As
acquisition by Medicago sativa and P-As interactions. The results indicate that fungal
colonization increased plant dry weight and also substantially increased both plant P
and As contents. The decreased shoot As concentrations were largely due to “dilution
effects” that resulted from simulated growth of AM plants and reduced As partitioning
to shoots.
Xia et. al. (2007) examined the effects of arbuscular mycorrhizal fungus
(Glomus mosseae) and P addition on As uptake by maize plants from an As-
contaminated soil. The results indicated that addition of P inhibited root colonization,
shoot and root biomass and development of extraradical mycelium. Root length. Dry
16
weight and shoot and root As contaminations both increased with mycorrhizal
colonization under the zero-P treatments. AM fungal inoculation decreased shoot As
concentrations when no P was added. AM colonization therefore appeared to enhance
plant tolerance to As in low P soil, and have some potential for the phytostabilization
of As-contaminated soil.
Ultra et al. (2007) set up an experiment to find out the effects of arbuscular
mycorrizal (AM) and phosphorus application on arsenic toxicity in As-contaminated
soil. The treatments consisted of a combination of two levels of AM (Glomus
aggregatum) inoculation and two levels of P application. AM inoculation as well as
P application reduced As toxicity symptoms and increased plant growth. Shoot As
concentrations were reduced by AM inoculation but enhanced by P application.
Dong et al. (2007) reported that, in a compartmented cultivation system white
clover and ryegrass were grown together in a As contaminated soil. The influence of
AM inoculation on plant growth, As uptake, phosphorus nutrition, and plant
competitions were investigated. Results showed that both plant species highly
depended on mycorrhiza for surviving the As contamination.
Trotta et al. (2006) studied the effects of arbuscular mycorrhizae on growth
and As hyperacumulation in the Chinese brake fern Pteris vittata. The As treatment
produced a dramatic increase of As concentration in pinnae and a much lower increase
in roots of both mycorrhizal and control plants. Mycorrhization increased pinnae dry
weight and leaf area, strongly reduced root As concentration and increased the As
translocation factor. The concentration of P in pinnae and roots was enhanced by
mycorrhizal fungi.
Kim et al. (2006) were investigated the effects of arbuscular mycorrhizal fungi
(Glomus mosseae) inoculation on arsenic and phosphorus uptake by Trifolium refresin
and Oentothera odorata. These results indicate that inoculation of AM fungi to host
17
plants obtained high yield and increased arsenic resistance to its toxicity and has a
potential applicability to enhance the efficiency of phyto-stabilization in soils highly
contaminated with arsenic.
Leung et al. (2006) conducted the greenhouse trial to investigate the role of
arbuscular mycorrhiza in aiding arsenic uptake and tolerance by Pteris vittata and
Cynodon dactylon. The infectious percentage of mycorrhizae and the average biomass
of shoots in infected P. vittata increased according to the increase of As levels when
compared to control. The indigenous mycorrhizas enhanced As accumulation in the
As mine populations of P. vittata and also sustained its growth by aiding P absorption.
For C. dactylon, As was mainly accumulated in mycorrhizal roots and translocation
to shoots was inhibited.
Ahmed et al. (2006) reported that Arsenic contamination of irrigation water
represents a major constraint to Bangladesh agriculture. This study examined the
effects of As and inoculation with an AM fungus, Glomus mosseae, on lentil. Plant
height, leaf/pod number, plant biomass and shoot and root P concentration/uptake
increased significantly due to mycorrhizal infection. Plant height, leaf /pod number,
plant biomass and shoot and root P concentration/uptake decreased significantly with
increasing As concentration. However mycorrhizal inoculation reduced As
concentration in roots and shoots. This study shows that growing lentil with
compatible AM inoculum can minimize As toxicity and increase growth and P uptake.
Agely et al. (2005) said that Chinese brake fern (Pteris vittata L.) is a
hyperaccumulator and mycorrhizal symbiosis may be involved in As uptake by this
fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role
in increasing plant phosphorus (P) uptake and ferns are known to be colonized by AM
fungi. They found that the AM fungi not only tolerated As amendment, but their
presence increased found dry mass at the highest As application rate. These data
18
indicate that AM fungi have an important role in arsenic accumulation by Chinese
brake fern.
Liu et al. (2005) conducted a glasshouse experiment to sudy the effect of
arbuscular mycorrhizal (AM) colonization by Glomus mosseae on the yield and
arsenate uptake of tomato plants in soil experimentally contaminated with five As
levels. Mycorrhizal colonization was little affected by As application and declined
only in soil amended with 150 mg Askg-1. Shoot As concentration increased with
increasing As addition up to 50mgkg-1 but decreased with mycorrhizal colonization.
Mycorrhizal plants had higher shoot and root P/As ratios at higher As application rates
than did non-mycorrhizal controls. Mycorrhizal colonization may have increased
plant resistance to potential As toxicity at the highest level of As contamination.
Gonzalez et al. (2002) studied the role of arbuscular mycorrhizal fungi (AMF)
in arsenate resistance in arbuscular mycorrhizal associations for two Glomus spp.
isolated from the arsenate-resistant grass Holcus lanatus. Glomus mosseae and
Glomus caledonium were isolated from H. lanatus growing on an arsenic-
contaminated mine-spoil soil. The arsenate resistance of spores was compared with
nonmine isolates using a germination assay. Short-term arsenate influx into roots and
long-term plant accumulation of arsenic by plants were also investigated in uninfected
arsenate resistant and nonresistant plants and in plants infected with mine and
nonmine AMF. Mine AMF isolates were arsenate resistant compared with nonmine
isolates. Resistant and nonresistant G. mosseae both suppressed high-affinity
arsenate/phosphate transport into the roots of both resistant and nonresistant H.
lanatus. Resistant AMF colonization of resistant H. lanatus growing in contaminated
mine spoil reduced arsenate uptake by the host. AMF evolved arsenate resistance, and
conferred enhanced resistance on H. lanatus.
19
2.3. Interaction of AMF and nematode
Yang et al. (2014) found that AMF enhanced plant tolerance to herbivores,
nematodes, and fungal pathogens and also found reciprocal inhibition between AMF
and nematodes as well as fungal pathogens, but unidirectional inhibition for AMF on
herbivores. Negative effects of AMF on biotic stressors of plants depended on
herbivore feeding sites and actioning modes of fungal pathogens. More performance
was reduced in root-feeding than in shoot-feeding herbivores and in rotting- than in
wilt-fungal pathogens. However, no difference was found for AMF negative effects
between migratory and sedentary nematodes.
Hayder et al. (2014) A 60 days greenhouse experiment was conducted to
evaluate the efficacy of certain rhizobacteria (P. fluorescens, B. subtilis, Azotobacter
spp.), mycorrhizal fungi (Glomus fasciculatum) alone and in combination on the
multiplying on Meloidogyne incognita and growth of brinjal. The experiment
consisted of eighteen treatments with four replicates arranged in RBD. The plants
treated with the combinations of certain rhizobacteria and mycorrhizal fungus
significantly suppressed number of galls per root system, second stage juveniles J2
and improved plant growth over control, single treatments of rhizobacteria,
Mycorrhizal fungus and Carbofuran 3G (chemical check). P. fluorescens, B. subtilis,
G. fasciculatum when used in combination showed intermediary effects on both
nematode reproduction and plant growth, while Azotobacter sp. was found to be least
effective.
Banuelos et al. (2014) studied on biocontrol traits of arbuscular mycorrhizal
fungi (AMF), in terms of single and mixed species inoculum, against the root knot
nematode Meloidogyne incongita in Impatiens balsamina L., with and without
mineral fertilization in a greenhouse pot experiment. At harvest, 60 days after sowing,
general plant growth parameters and plant defense response in terms of antioxidant
20
activity and content of phenolic compounds in roots and leaves were measured. Also
AMF root colonization and abundance of nematode root-knots were determined.
Mineral fertilization increased all plant growth parameters measured, which coincided
with an increased disease development caused by M. incognita. Inoculation with AMF
mitigated the observed plant growth reduction caused by M. incognita though, higher
abundance of M. incognita root knots was found in mycorrhizal plants.
Marro et al. (2014) found that a possible biological control alternative to reduce
the damage caused by this species may be the use of arbuscular mycorrhizal fungi
(AMF). In the present work, the effect of Glomus intraradices on tomato plants
inoculated with the nematode at transplanting and three weeks later was tested. At 60
days, the following parameters were estimated: percentage of AMF colonization, root
and aerial dry weight, number of galls and egg masses, and reproduction factor
(RF=final population/initial population) of N. aberrans. AMF colonization was higher
in the presence of the nematode. The use of AMF favoured tomato biomass and
reduced the number of galls and RF on the plants inoculated with the nematode at
transplanting.
Udo et al. (2013) carried out an experiment to investigate the single and
combined effects of different arbuscular mycorrhizal fungi (AMF) and bio formulated
Paecilomyces lilacinus against M. incognita race 1 on tomato. Dysteric Cambisol soil
was used. The experiment took place in Calabar, Cross River State, Nigeria. The
experiment was laid out as a 3x6 factorial in a completely randomized design (CRD)
with three replications. Three applications of the bionematicide were combined with
five species of AMF plus an uninoculated control. The results indicated that AMF
species differed significantly (p < 0.05) in their efficacy of gall and egg mass
inhibition, tomato root colonization rate as well as growth and fresh fruit yield
enhancement. Glomus etunicatum and G. deserticola were the most efficient species.
Two applications of the bionematicide more significantly (p < 0.05) reduced galling
21
and egg production than a single application. Individual combinations of two AMF
(G. etunicatum and G. deserticola) with a double application of the bionematicide,
resulted in the greatest gall and egg mass inhibition and consequently the greatest
growth and fresh fruit yield enhancement.
Aggangan et al. (2013) conducted a study to determine the potential of
arbuscular mycorrhizal fungi (AMF) and nitrogen fixing bacteria (NFB) bio fertilizers
as growth promoters and biological control agents against nematodes in tissue-
cultured banana var. Lakatan under screen house conditions. Meriplants were
inoculated with AMF (MykovamTM) and NFB (Bio-NTM) during planting in
individual plastic bags filled with sterile soil sand mixture. Plant parasitic nematodes,
Radopholus similis and Meloidogyne incognita suspension were poured into the soil,
two months after inoculation with biofertilizers at concentrations of 1,000 and 5,000
larvae or eggs per seedling, respectively. Plant height, pseudostem diameter and leaf
area were taken every 2 weeks. At fourth month, results showed that AMF and
AMF+NFB inoculated seedlings grew better than the control plants. AMF treated
plants were taller, had bigger pseudostem diameter, larger leaf area, highest fine,
coarse root and total plant dry weights than the control and the other treatments. AMF
reduced root galls by 33% relative to those inoculated with M. incognita.
Hajra et al. (2013) conducted an experiment to evaluate the efficacy of
arbuscular mycorrhizal (AM) fungi (Glomus spp. and Gigaspora spp.) as bio-
protectant against root-knot nematode Meloidogyne incognita in sponge gourd (Luffa
cylindrica (L.) Roem.), mycorrhizal plant of family Cucurbitaceae. All parameters
were estimated in roots, shoot and leaves of mycorrhizal and nonmycorrhizal plants.
Physical/biochemical and carbon profile were taken into account. Comparative study
clearly indicates the significant variations in all parameters. Leaf area and plant height
were increased in mycorrhizal plants than non-mycorrhizal, while it showed a sharp
22
decrease in nematode infected plants, same plants also showed less water content due
to xylem vessels damage.
Vos et al. (2012) investigated the effects of AMF and mycorrhizal root
exudates on the initial steps of Meloidogyne incognita infection, namely movement
towards and penetration of tomato roots. M. incognita soil migration and root
penetration were evaluated in a twin-chamber set-up consisting of a control and
mycorrhizal (Glomus mosseae) plant compartment (Solanum lycopersicum cv.
Marmande) connected by a bridge. Penetration into control and mycorrhizal roots was
also assessed when non-mycorrhizal or mycorrhizal root exudates were applied and
nematode motility in the presence of the root exudates was tested in vitro. Results M.
incognita penetration was significantly reduced in mycorrhizal roots compared to
control roots. In the twin-chamber set-up, equal numbers of nematodes moved to both
compartments, but the majority accumulated in the soil of the mycorrhizal plant
compartment, while for the control plants the majority penetrated the roots.
Application of mycorrhizal root exudates further reduced nematode penetration in
mycorrhizal plants and temporarily paralyzed nematodes, compared with application
of water or non-mycorrhizal root exudates.
Herman et al. (2012) studied the effects of inoculation of sweet passion fruit
plants with the arbuscular mycorrhizal (AM) fungus Scutellospora heterogama on the
symptoms produced by Meloidogyne incognita race 1 and its reproduction were
evaluated in two greenhouse experiments. In the 1st, the M. incognita (5000
eggs/plant) and S. heterogama (200 spores/plant) inoculations were simultaneous; in
the 2nd, the nematodes were inoculated 120 days after the fungal inoculation. In both
the experiments, 220 days after AM fungal inoculation, plant growth was stimulated
by the fungus. In disinfested soil, control seedlings (without S. heterogama) were
intolerant to parasitism of M. incognita, while the growth of mycorrhized seedlings
was not affected. Sporulation of S. heterogama was negatively affected by the
23
nematodes that did not impair the colonization. M. incognita did not affect
mycorrhizal seedling growth.
Adriano et al. (2011) conducted an experiment where banana plants (Musa spp.
L.) cv 'Great dwarf' were amended with free-living N2 fixing bacteria (FLNFB) and
arbuscular mycorrhizal fungi (AMF) and the presence of the burrowing nematode
Radopholus similis was monitored in the field. Five treatments were applied by
inoculating banana roots with four strains of FLNFB, that is C1, C2, C3 and C4
isolated from the rhizoplane of the same banana cultivar, or by keeping them
uninoculated. The largest number of nematodes was found in the untreated roots and
the lowest in the roots inoculated with C4. The largest percent of mycorrhizal
colonization was found when banana roots were inoculated with C1 and the lowest in
roots that were not inoculated. The number of R. similis decreased with increased
colonization with AMF.
Shreenivasa et al. (2011) conducted an experiment where Tomato
Lycopersicon esculentum Cv. Pusa ruby inoculated with indigenous isolates of
Glomus fasciculatum and Meloidogyne incognita individually and in combination
were analyzed for sequential biochemical variations in roots with respect to total
proteins, phenols and polyphenol oxidase activity. There was a post inflectional
increase in the concentration of total proteins in G. fasciculatum, M. incognita + G.
fasciculatum and M. incognita inoculated roots, respectively. Concentration of
phenols and polyphenol oxidase activity was higher in inoculated roots as a result the
nematode infection reduced in Glomus infected root.
Manandhar et al. (2011) explored the biocontrol effect of different species of
arbuscular mycorrhizal fungi (AMF) (Glomus intraradices and G. mossae) was tested
against Meloidogyne graminicola in rice (Oryza sativa) cultivars Azucena and
UPLRi5 under greenhouse conditions. Seed - based inoculum and root-based
24
inoculum were used for G. intraradices in Azucena, while in vivo cultured G. mossae
was used for UPLRi5. Calcium alginate beads were used as inoculant carrier for the
entrapment of G. intraradices propagules in rice seeds. Low percentage of
colonisation was observed for G. intraradices while percentage of G. mossae
colonisation varied between experiments. G. intraradices did not show biocontrol,
however, despite lower colonisation, G. mossae exhibited suppression of the
nematode multiplication. Variations in the control efficiency of different species of
Glomus in different rice cultivars indicate the host-AMF specificity to achieve control.
Further study is needed in order to optimize AMF colonisation in rice and to determine
the biocontrol potential of AMF against M. graminicola which is a major problem in
all rice growing areas.
Ambo et al. (2010) conducted a glass house experiment for the effectiveness
of vermicompositing and rhizotrophic micro-organisms (arbuscular mycorrhizal
fungus (AMF) Glomus aggregatum and mycorrhiza helper bacterium (MHB) Bacillus
coagulans) for the management of Meloidogyne incognita on tomato cv Pusa Ruby.
Among the different treatments evaluated, vermicompost and G. aggregatum alone
and in combination with B. coagulans recorded the maximum growth, biomass and
nutrients of tomato cv Pusa Ruby with decreased root- knot nematode population and
root- knot index. But amending the soil with application of vermicomposting + B.
coagulans + G. aggregatum in tomato was significantly increased the plant growth,
biomass and nutrients of tomato cv Pusa Ruby. Similarly, reduction in root- knot
nematode population, root- knot index (RKI), nematode reproduction rate (NRR)
number of galls and egg masses per plant were recorded in the above treatment.
Highest mycorrhizal colonization of 92.5% and minimum nematode population of
145.0/ 250cc soil was observed in the same treatment.
Akhtar et al. (2009) studied on the effects of Phosphate solubilizing
microorganisms (Glomus intraradices, Pseudomonas putida, P. alcaligenes, P.
25
aeruginosa (Pa28), A. awamori) and Rhizobium sp. on the growth, nodulation yield
and root-rot disease complex of chickpea under field condition. Inoculation of
Rhizobium sp. caused a greater increase in growth and yield than P. putida, P.
aeruginosa or G. intraradices. The number of nodules per root system was
significantly higher in plants inoculated with Rhizobium sp. compared to plants
without Rhizobium sp. Inoculation of P. putida caused highest reduction in galling
followed by P. aeruginosa, P. alcaligenes, G. intraradices and A. awamori while
Rhizobium sp. caused almost similar reduction in galling as caused by P. putida.
Sankaranarayanan et al. (2009) conducted an experiment under glasshouse
conditions to study the reciprocal influence of the arbuscular mycorrhizal fungus
(AMF) Glomus fasciculatum and the root-knot nematode Meloidogyne incognita and
their interaction effects on the growth of blackgram. Prior inoculation of AMF
increased significantly shoot and root growth and pod yield of blackgram, especially
when applied 20 days before nematode inoculation, and suppressed root gall index
and the nematode population in the soil, with earlier application of AMF resulting in
greater suppression of the nematode. Inoculation of the nematode prior to AMF
affected negatively root mycorrhizal colonization and spores in the soil with the
suppressing effects being more pronounced when nematodes were inoculated 20 days
prior to AMF. AMF treatments increased phosphorus content of shoots and roots of
blackgram.
Jefwa et al. (2008) found up to 20 AMF species to be associated with banana
plantations (Musa spp.) in East and Central Africa. Spore abundance, the inoculum
reservoir that determines colonization, is largely influenced by management practices.
The data generated to date increasingly illustrates the importance of AMF in banana
systems and its sensitivity to crop and soil management practices, effects on banana
growth, nutrient uptake and control of root damage by nematodes.
26
Siddiqui et al. (2008) carried out an experiment on the effects of Glomus
intraradices and Pseudomonas putida which were observed alone and in combination
with fertilizers (composted cow manure and urea) on the growth of tomato and on the
reproduction of Meloidogyne incognita. Inoculation of P. putida caused a greater
increase in the tomato growth than G. intraradices and inoculation of both together
caused a greater increase than by either of them. The maximum reduction in galling
and nematode multiplication was observed when P. putida was used with G.
intraradices together with composted manure.
Siddiqui et al. (2007) investigated the effects on chickpea (Cicer arietinum) of
the phosphate-solubilizing microorganisms Aspergillus awamori, Pseudomonas
aeruginosa (isolate Pa28) and Glomus intraradices in terms of growth, and content of
chlorophyll, nitrogen, phosphorus and potassium and on the root-rot disease complex
of chickpea caused by Meloidogyne incognita and Macrophomina phaseolina.
Application of these phosphate-solubilizing microorganisms alone and in
combination increased plant growth, pod number, and chlorophyll, nitrogen,
phosphorus and potassium contents, and reduced galling, nematode multiplication and
root-rot index of chickpea. Pseudomonas aeruginosa reduced galling and nematode
multiplication the most followed by A. awamori and G. intraradices.
Jaizme-Vega et al. (2006) aimed of study to determine whether the combined
inoculation of two AMF species and a Bacillus consortium based on three strains
previously described as PGPR in other crops were able to reduce nematode infection
and damage on papaya. Papaya seedlings were inoculated with two AMF isolates
(Glomus mosseae or G. manihotis) at the beginning of the nursery phase. Results in
terms of plant development and nutrition, benefits due to AMF inoculation persisted
in the presence of PGPR. However, the effect of dual inoculation was different,
depending on the Glomus species. This positive effect was also evident in plants with
nematode. Meloidogyne infection was significantly reduced in mycorrhizal plants.
27
However, the addition of PGPR does not seem to improve the results of AMF single
treatments in terms of nematode infection.
Masadeh et al. (2004) studied the effects of the combination of the arbuscular
mycorrhizal fungus (AMF) Glomus intraradices and the biological control fungus
Trichoderma viride on the control of the root-knot (RK) nematode, Meloidogyne
hapla, were investigated in greenhouse experiments on the tomato cultivars ‘Hildares’
(very suitable as host for RK) and ‘Tiptop’ (less suitable as host for RK) showing
retarded development of the giant cell system, retarded growth of the nematode, and
consequently reduced production of egg-sacs. There was no evidence of negative
interactions between the two beneficials with regard to AMF root colonization or
population development of T. viride in the rhizosphere.
28
2.4. Interaction of P. lilacinum and M. incognita
Aminuzzaman et al. (2013) used alginate pellets of Paecilomyces lilacinus
YES-2 and Pochonia chlamydosporia HDZ-9 for controlling of M. incognita on
tomato in a greenhouse by adding them into a soil with sand mixture at rates of 0.2,
0.4, 0.8 and 1.6% (w/w). P. lilacinus pellets at the highest rate (1.6%) reduced root
galling by 66.7%. P. chlamydosporia pellets at the highest rate reduced the final
nematode density by 90%. The results indicate that P. lilacinus and P.
chlamydosporia as pellet formulation can effectively control root-knot nematodes.
Usman et al. (2012) observed the effect of some fungal strains for the
management of root-knot nematode (Meloidogyne incognita) on eggplant (Solanum
melongena. They used two biocontrol fungal strains of Trichoderma harzianum and
Paecilomyces lilacinus at 1g/pot and 2g/pot. Inoculation of fungus was done
simultaneously along with 1000 second stage juveniles (J2) of M. incognita. Strains
of T. harzianum were found to be most effective when treated at 2g/pot. P. lilacinus
also gave almost similar results and enhanced all plant growth characters with the
reduction in the root knot infestation.
Kiewnick et al. (2011) evaluated the fungal bio-control agent, P. lilacinus
strain 251 for its potential to control the root-knot nematode Meloidogyne incognita
on tomato at varying application rates and inoculums densities. He demonstrated that
a pre-planting soil treatment with the lowest dose of commercially formulated PL251
(2×105 CFU/g soil) was already sufficient to reduce root galling by 45% and number
of egg masses by 69% when averaged over inoculums densities of 100 to 1600 eggs
and infective juveniles per 100 cm3 of soil. A real time PCR revealed a significant
relationship between egg mass colonization by PL 251 and the dose of product applied
29
to soil but no correlation was found between fungal density and biocontrol efficacy or
nematode inoculums level. These results demonstrate that rhizosphere competence is
not the key mode of action for PL 251 in controlling M. incognita on tomato.
Aminuzzaman and Liu (2011) first reported the isolation and evaluation of
biocontrol fungus Paecilomyces lilacinus recorded in Bangladesh. The results under
pot experiment and field experiment demonstrated significant variation among the
treatment. They mentioned that the fungus showed more than 80% egg parasitism and
52% juvenile mortality of Meloidogyne spp. They also reported that the fungus
increased shoot height, fresh shoot weight, root length and fresh root weight and also
reduced root galling up to 30% and number of eggmass per root system up to 40%
when compared to control treatment. P. lilacinus enhanced plant growth and reduced
galling index and nematode population which was supported by Aminuzzaman et al.
(2011). They also reported that root galling index and final nematode population
decreased up to 40.7 and 73.8% respectively for brinjal of application of the biocontrol
fungus. They also mentioned that P. lilacinus enhanced plant growth and reduced
galling index with its increased doses.
Kalele et al. (2010) worked with antagonistic fungus P. lilacinus strain 251 in
controlling root knot nematodes in tomato and cucumber. He applied P. lilacinus
inoculums at different rates and different times. He found that pre-planting soil
treatment reduced final nematode populations by 69% and 73% in the roots and soil,
respectively compared to the non-inoculated control in tomato. However, soil
treatment at planting recorded reduction level of 54 and 74% in the roots and soil
respectively he described that PL251 was a promising potential that could be exploited
in the management of Meloidogyne spp. in vegetable production systems.
Aminuzzaman (2009) used fungal pellet containing spores of nematophagous
fungus P. lilacinus YES-2 in green house condition to assess its biocontrol potency
30
against root knot of tomato and observed P. lilacinus significantly reduced the number
of nematode population in soil and root and increased 20.75% tomato yield over
untreated control.
Bhat et al. (2009) observed the interaction of fungus P. lilacinus and in
Meloidogyne incognita in bitter gourd at different time intervals. They found that
Meloidogyne incognita induced large sized galls on the plants. The xylem and the
phloem exhibited abnormalities in structure near the giant cells. Abnormal vessel
elements were occupying larger area near giant cells. The plants that were treated with
fungus either one week before nematode inoculation or simultaneously produced
significantly (P+0.01) small sized galls in comparison to untreated plants.
Lopez-llorca et al. (2008) observed the mode of action and interactions of
nematophagous fungi and discussed types of recondition phenomena (e.g. chemotaxis
and adhesion), signaling and differentiation, penetration of the nematode
cuticle/eggshell using mechanical as well as enzymatic (protease and chitinase)
means. They observed that P. lilacinus is an egg and female parasitic fungus and it
infects nematode by its appressoria. It produced chitinases enzymes and damage the
eggshell and destroyed nematode.
Singh (2007) examined root galls of rice caused by Meloidogyne graminicola
for natural colonization by nematophagous fungi and observed that application of
inocula of A. dactyloides and D. brachophaga in soil infested with Meloidogyne
graminicola respectively reduced the number of root galls by 86% and females by
94% and the eggs and juveniles by 94%. The application of these fungi to soil
increased plant growth.
Anastasiadis et al. (2007) evaluated a formulated product (BioAct) is made up
of the spores of the naturally occurring fungus P. lilacinus, strain 251, against root
31
knot nematodes in pot and green house experiments. They observed that application
of P. lilacinus and the bacteria Bacillus fitmus, significantly or together in pot
experiments, provided effective control of second stage juveniles, eggs or egg masses
of root knot nematodes.
Esphahani and Pour (2006) observed that P. lilacinus was effective in
controlling root knot nematode on tomato and suppressing its population growth and
effectively promoted the growth of plant.
Khan et al. (2006) described the mode and severity of infection of nematodes
by a soil saprophyte P. lilacinus. Infection of stationary stages of nematodes by P.
lilacinus was studied with three plant parasitic nematodes M. javanica, Heterodera
avenae and radopholus similis.P. lilacinus infected eggs, juveniles and females of M.
javanica by direct hyphal penetration. The early developed eggs were more
susceptible than the eggs containing fully developed juveniles. P. lilacinus also
infected immature cyst of H. avenae including eggs in the cysts and the eggs of R.
similis and the fungus was shown to infect mobile stages of all the plant-parasitic
nematodes.
Kiewnick and Sikora (2006) mentioned that successful biocontrol of RKN
depends on initial low nematode density in the soil. They used fungal biocontrol agent,
P. lilacinus strain 251 (PL251), and evaluated for its potential to control the root knot
nematode Meloidogyne incognita on tomato. In growth chamber experiment, a pre-
planting soil treatment reduced root galling by 66% number of egg masses by 74%
and the final nematode population in the roots by 71% compared to the inoculated
control. They also mentioned that a single pre-plant application at a concentration of
1× 106 CFU/g is needed for sufficient biocontrol of Meloidogyne incognita by PL251.
32
Kiewnick and Sikora (2004) conducted a greenhouse experiments to control
root knot nematodes Meloidogyne incognita and M. hapla on tomato using P. lilacinus
251. All single or in combination treatments tested decreased the gall index and the
number of egg masses compared to the untreated control 12 weeks after planting.
However, the combination of the seedling treatment with a pre or at planting
application of P. lilacinus was necessary to achieve higher levels of control. They
found that the above mentioned combination of pre-planting application plus the
seedling and one post plant drench gave the best control and resulted in a significant
fruit yield increase in concurrence with a decrease in number of galls per roots.
Oduor-owino (2003) used agrochemicals, organic matter and the antagonistic
fungus P. lilacnus in controlling root knot nematode in natural field condition. He
found that the smallest galling index, number of galls and nematode population were
in soil treated with aldicarb in combination with P. lilacinus.
Rao and Reddy (2001) used Glomus mossae in combination with P. lilacinus
and neem cake to control root knot nematode of eggplant. The parasitization of eggs
of root knot nematode was significantly increased by P. lilacinus and the transplants
yielded significantly more fruit. Neem cake amendment in the nursery beds played a
positive role in increasing the colonization of endomycorrhiza and the biocontrol
fungus on the roots of transplants before and after transplanting. The combined effect
of these three components facilitated the sustainable management of M. incognita on
eggplants under field condition.
Siddiqui et al. (2000) studied the efficacy of Pseudomonas aeruginosa alone
or in combination with P. lilacinus on controlling of root knot nematode and root
infecting fungi under laboratory and field conditions. Ethyl acetate extract (1mg/ml)
of P. lilacinus and P. aeruginosa, respectively, caused 100 and 64% mortality of
Meloidogyne javanica larvae after 24h. In field experiments, biocontrol fungus and
33
bacterium significantly suppressed soil bore root infecting fungi including
Macrophomina phaseolina, Fusarium oxysporum, Fusarium solani, Rhizoctonia
solani and the root knot nematode Meloidogyne javanica, P. lilacinus parasitized eggs
and female of Meloidogyne javanica.
Oduor and Waudo (1996) evaluated P. lilacinus, Phoma herbarum and three
isolates of Fusarium oxysporum in controlling root knot (M. javanica) in eggplant. P.
lilacinus and Fusarium oxysporum-1 significantly (p<0.05) parasitized more than
70% eggs and female while Fusarium oxysporum-3 parasitized less than 20% control
of Meloidogyne incognita in eggplant.
Mittal et, al. (1995) evaluated P. lilacinus, a rhizosphere inhabiting
nematophagous fungus, along with chitin in sterilized soil for the suppression of
Melooidogyne incognita, causal agent of root knot disease in Solanum melongena,
Lycopersicon esculentum and Cicer arietinum. The plant growth after 30, 60 and 90
days was assessed in terms of shoot and root length, shoot and root fresh and dry
weight and number of galls/gm root fresh weight. Combination of fungus wth chitin
enhanced suppression of Meloidogyne incognita more than using them alone.
Cabanillas et al. (1989) isolated of 13 P. lilacinus isolates from various
geographic regions as biocontrol agents against Meloidogyne incognita. The best
control of M. incognita was provided by an isolate from Peru or a mixture of isolated
of P. lilacinus. As soil temperatures increased from 16OC to 28OC, both root knot
damage caused by M. incognita and percentage of egg masses infected by P. lilacinus
increased. The greatest residual P. lilacinus activity on M. incognita was attained with
a mixture of fungal isolates. These isolates effected lower root galling and necrosis,
egg development, and enhanced shoot growth compared with plants inoculated with
M. incognita alone.
34
Cabanillas and Barker (1989) conducted a microplot experiment to evaluate
the inoculam level and time of application of P. lilacinus on the protection of tomato
against M. incognita. They observed that P. lilacinus applied into soil 10 days before
planting increased yield with the improvement of plants compared with the nematode
alone plots.
35
MATERIALS AND METHODS
3.1. Experimental site and experimental period
The present investigation was carried out during the period from September 2014 to
July 2015 in the shade house and in the laboratory of the Department of Plant
Pathology, Sher-e-Bangla Agricultural University, Sher-e Bangla Nagar, Dhaka -
1207.
3.2. Environment of experiments
All the experimental plants were kept in the shade house where the temperature was
28 ± 2º C during the “day” and 23 ± 2º C during “night” with an average temperature
of 26± 2º C.
3.3. Pot Experiment
3.3.1. Crop variety used
Eggplant variety BARI Begun-10 was used as selected crop in this experiment.
3.3.2. Collection of seeds
Seeds of BARI Begun-10 was collected from Bangladesh Agricultural Research
Institute (BARI), Joydebpur, Gazipur.
3.3.3. Soil collection and sterilization
Required soils were collected from agricultural farm of Sher-e-Bangla Agricultural
University. Sand, decomposed cow dung and compost were also collected with soil.
Then soil, sand, cow dung and compost mixed properly in a ratio of 6:3:1. For raising
seedlings in plastic trays and for final experiment set up the mixture was autoclaved
at 121ºC, 15 psi for 15 minutes on two successive days. The sterilized soil was allowed
to cool to room temperature and was later used to fill the plastic trays for raising
seedlings and pot for seedling transplanting.
36
3.4. Raising of seedlings
Several plastic trays were filled with sterilized and fertile soil. Seeds of BARI Begun-
10 was soaked in water for one night and treated with NaOCl for one minute and
washed with distilled water for three times. After that the seeds were sown in plastic
trays and covered with a thin layer of soil and watered. Then the trays were covered
with polythene sheet and kept in sunlight for raising seedlings (Photograph 1.).
Seedlings were observed regularly and watering was done as per necessity up to
hardening the seedling in plastic pot.
Photograph 1. Raising of eggplant seedlings
37
3.5. Preparation of pots
Plastic pots of 1000 cm3 were cleaned, washed and dried up. Sterilized and fertile soil
was filled in required amount into each pot. Each pot contained 600 g soil. Then the
pots were arranged according to selected experimental design. Detailed of soil
properties presented in Table1.
Table 1. Physicochemical characteristics of pot soil
PH Organic
matter
Total
N
K Ca Mg P S B Zn
% Meq/100 gm µg/gm(ppm)
6.6 2.29 0.114 0.16 8.22 1.71 4.84 9.99 0.14 5.35
38
3.6. Treatments and design of the experiment
3.6.1. Treatments
There were sixteen integrated treatment combination: 2 (1 Glomus sp. + 1control) x 2
(1 P. lilacinum + 1 control) x 2 (1 Arsenic + 1 control) x 2 (1 M. incognita + 1 control).
1. C
2. C+G
3. C+Pl
4. C+Mi
5. C+As
6. G+As
7. Pl+As
8. Mi+As
9. G+Mi+As
10. Pl+Mi+As
11. G+Pl+As
12. G+Pl+As+Mi
13. G+Mi
14. G+Pl
15. Pl+Mi
16. G+Pl+Mi
C= Control, G= Glomus sp., Pl= Purpureocilium lilacinum, Mi= Meloidogyne incognita, As=
Arsenic
3.6.2. Design of the experiment
The experimental design was CRD with 5 replicated pots per treatment. Plants were
disposed in the shadehouse
39
3.7. Isolation, identification and culturing of AMF
Spores of AMF in soil was collected by the wet sieving and decanting method
(Gerdeman and Nicolson, 1963) followed by sucrose density gradient centrifugation
technique described by Daniel and Skipper (1982). After collection of roots and
rhizosphere soil of Cassia tora, approximately 100 g of root and rhizosphere soil was
separately suspended into a 2-liter container and 1.5 liter distilled water was added.
Vigorous mixing of the suspension was done to make free of spore from soil
(photograph 2.) and roots. For root sample blending the sample for 1 min in 300 ml
of distilled water was essential to free the spore from roots. Heavier particles in
suspension was allowed to settle for 15 to 45s and the supernatant was decanted
through standard sieves. A 500 um pore sieve over a 50 µm pore size sieves was used.
Suspension was transferred to 50 ml centrifuge tubes with a fine stream of water and
was centrifuge at 1200 to 1300x for 3 min. the suspension was removed carefully. Soil
or root particle (pellet) was suspended in chilled 1.17 M sucrose, mixing the content
and centrifuge again at 1200 to 1300x for 1.5 min. The supernatant was poured
through small mesh sieve and rinse carefully with distilled water and wash the spores
sufficiently. Spores were sterilized following Budi et al. (1999) by immersed for 10 s
in 96% ethanol and washed using a 25 um sieve. Spores will then be immersed for 10
min in a solution of .02% streptomycin, 2% chloramines T and a drop to Tween 20
followed by subsequent washing in 25 um sieve. A final emersion was done in 6%
bleach for 1 min and subsequent washing in distilled water. The AMF was sterilized
with 1% sodium hypochlorite for 2 min, rinsed three times in distilled water and sown
in 50 multi-pot trays containing soil of lower P content which was previously
inoculated by sufficient spore of AMF inoculation was done following (Jaizmevega
et al. 2005). Maize seedlings were allowed for sufficient root and soil colonization.
The multi-pot trayswere kept in shade house and irrigated regularly. After 8 weeks,
AMF colonized root fragments (photograph 3) of seedlings and rhizosphere soil
containing spore were used for AMF treatment.
40
Photograph 2. Identification of Glomus sp. (40x)
Photograph 3. Confirmation of colonization observing vesicle inside
the cell of Cassia tora(40x)
Spore
Vesicle
41
Photograph 4. Inoculation of Glomus spore on maize seed (40x)
Photograph 5. Inoculation of Glomus spore in maize root (40x)
Spore
Maize seed
Maize root
Spore
42
Photograph 6. Mass culture of Glomus sp. with trap plant maize
43
3.8. Fungal Isolate
The isolate of Purpureocillium lilacinum isolated from Mymensingh, Bangladesh,
previously shown to have high biocontrol ability against root knot nematode was used
in this study (Aminuzzaman and Liu, 2011).
3.8.1. Culture, mass production and harvesting of Purpureocillium lilacinum
Purpureocillium lilacinum was grown on Potato Dextrose Agar (PDA) medium for 8-
10 days (Photograph 7) (Aminuzzaman and Liu, 2011). Within 8-10 days the fungus
was transferred on chick pea for mass production (Photograph 8). For mass production
one hundred grams of chickpea seed free of any pesticide treatment was placed in 250-
ml conical flasks and soaked in lukewarm water for 3-4 hours. Then the water was
drained off, and each flask was closed with a cotton plug and covered with brown
paper in two layer of paper. Then flasks were placed in an autoclave for 15 minutes at
121OC temperature at 15 psi. After the flasks and contents cooled, P. lilacinum as a
mycelial mat growing on PDA was added aseptically to one flask and shaken for better
distribute of the fungus; the other flask served as an un-inoculated control. The flasks
were incubated at 25-30OC for 20 days. After incubation the sterile water was added
into the conical flask and the spore masses scraped away with sterile brush within
laminar air flow chamber. The harvested spores were filtered through sterilized
cheesecloth. The spore was harvested from each conical flask and spore was counted
with a hemocytometer.
44
Photograph 7. Pure culture of P. lilacinum on PDA media
Photograph 8. Mass culture of P. lilacinum on chick pea
45
3.9. Nematode inoculum preparation
The RKN was maintained on eggplant (Photograph 9) in shade house for two months
and the eggs was extracted from the roots following sucrose floatation method as
described by Liu and Chen (2001). The fresh roots were collected from the shade
house into plastic bag and nematode extraction was carried out within two days. The
collected roots (Photograph 10) were washed in running tap water and cut into 1.5
small pieces. The cut pieces were crushed in 500 ml sterile water with a mini sample
blender for 1min at high speed. The suspensions were treated with 1% sodium
hypochlorite (NaOCl) for 1 min to dissolve eggs was collected on 25 µm aperture
sieve. The eggs were washed three times with sterile distilled water to remove residual
NaOCl and collected in a 50 ml plastic tube. The eggs were separated from debris by
centrifugation in 37.5% (w/v) sucrose solution for 5 min and then was rinsed with 1%
NaOCl for 1 min and washed three times with sterile distilled water to remove residual
NaOCl and collected in 50 ml plastic tube. Eggs was adjusted to 500 eggs/100 µl
suspension.
46
Photograph 9. M. incognita inoculum production in association with eggplant root
Photograph 10. M. incognita infected root showing eggmass and gall
47
3.10. Preparation of arsenic solution
Arsenic solution was prepared following Elahi et al. (2010). For preparation of 1000
ppm 1L arsenic solution at first 4g of sodium hydroxide was taken in a 100ml
measuring cylinder. Sodium hydroxide was diluted with distilled water and the
volume of the cylinder rose up to the 100 ml mark. Then 1.32g arsenic powder was
taken in another 1000 ml measuring cylinder and dilute with that diluted sodium
hydroxide. 10% HCl was taken in a beaker. Then HCl was added into the 1000ml
measuring cylinder to make it acidic. Finally, the volume of the flask rose up to the
1000ml mark.
3.11. General inoculation procedure for the experiment
Each plastic pot (600cm3) was filled with the 500 cm3 soil. Fungal biocontrol agent
was added into soil and mixed thoroughly before 7 days of transplantation. To
determine specific CFU (5x106) of P. lilacinum/g soil, a separate experiment was
carried out where fungal inocula were added in 100 g soil in different rate and mixed
thoroughly with three replicates. Soil moisture to be maintained to field capacity.
After seven days of inoculation, CFU of P. lilacinus/g soil were determined following
soil dilution plate method and relationship between amount of P. lilacinum pellet
applied to the soil and CFU of P. lilacinum/g soil. Arsenic suspension was prepared
by dissolving arsenic powder in NaOH. Additional HCl were added to make it acidify.
As solution was mixed thoroughly with the pot soil at 50 ppm. As concentration was
confirmed by subsequent soil analysis following Beer’s law. Twenty-five gram AMF
colonized maize root and colonized rhizosphere soil was used for each pot soil.
Seedling of 30 days (BARI Eggplant 10 var.) was transplanted into each pot.
Nematode eggs at the rate of 10000 eggs/ pots was inoculated into the central area of
each pot through four 2cm depth holes. Each pot will have a dish underneath to
eliminate cross contamination and each treatment was replicated five times. Then,
pots were transferred to the shade house. Seedlings was irrigated with tap water daily.
48
3.12. Intercultural operations
After transplantation of seedling and final experiment set up weeding and irrigation
were regularly done as per necessity. General sanitation was maintained throughout
the growing period.
3.13. Harvesting and data recording
After two months of transplanting, plants were harvested and data was recorded.
The following parameters were considered
Shoot length (cm)
Root length (cm)
Shoot fresh and dry weight (g)
Root fresh and dry weight (g)
Leaf area (cm2)
Chlorophyll content (μg cm−2)
Mycorrhizal root infection (%)
Mycorrhizal spore (number/10gm soil)
Gall index (0-10 scale)
Number of egg masses per root
Number of eggs per egg mass
Number of eggs per root system
Number of juveniles per 800 g soil
Total number of nematode population/plant (J2+ eggs)
Reproduction factor (RF)
% Egg masses colonized by P. lilacinum
Soil colonization by P. lilacinum (CFUg-1 soil)
49
3.14. Data recorded
3.14.1. Plant data
Shoot and root length were measured before harvest. The shoot height (cm) was
measured from the base of the plant to the growing point of the youngest leaf with a
measuring scale. Then the roots are harvested by cutting with an anti-cutter. Roots are
carefully separated from soil, cleaned gently with water and collected in different
polybag that were leveled according to different treatments. Finally, the root length
(cm) was taken. The length of root was measured from the growing point of root to
the longest available lateral root apex. For fresh weight (g) of root and shoot was
blotted dry and the weight was recorded. For dry weight (g), the shoot and root were
sun dried for three days and then kept in drier machine for 4-6 hours at 40º C
temperatures. And after complete drying the weight was recorded. Leaf area (cm2)
was measured by leaf area meter (Photograph11) and chlorophyll content (µgcm-2) of
eggplant leaves were measured by chlorophyll meter (Photograph12).
50
Photograph 11. Leaf area measurement by CI-202 Portable Laser Leaf Area Meter
Photograph 12. Measurement of chlorophyll content of eggplant
leaf by SPAD 502 Plus Chlorophyll Meter
51
3.15. Counting of nematode egg masses/root system
Number of egg masses/root system was counted following Holbrook et al. (1983).
The roots were soaked in Phloxine-B (2mg/l) for 15 minutes (Photograph 13)
(Hartman and Sasser, 1985). The roots were observed and egg masses/root was
counted with a magnifying glass. Then egg masses were picked with forceps treated
with NaOCl for three minutes to dissolve gelatinous materials. After subsequent
washing with water eggs were counted under compound microscope (Photograph 14).
52
Photograph 13. Heavily galled root treated with Phloxine-B solution
Photograph 14. Phloxine-B treated root for counting of eggmass/ root
53
3.16. Slide preparation and counting of eggs/egg mass
Heavily galled roots were collected and properly washed with water. Care was taken
so that an egg mass does not washed with water. Then the roots were soaked in
Phloxine-B (2mg/l) solution for 15 minutes (Hartman and Sasser, 1985). Then water
was soaked by placing the root in tissue paper for one minute. A clean slide was
prepared. Three drops of glycerin were placed on the slide. Then egg masses were
collected from the root with the help of fine forceps and placed on the slide and also
crashed with the help of bottom side of needle. Then after placing cover slip the slide
was examined under microscope and counting the eggs/egg mass (Photograph 15).
3.17. Extraction of nematode from soil and counting of juveniles
The extraction of nematodes from soil was done by using a Whitehead and Hemming
tray method (1965) as follows: Pot soil was mixed thoroughly and different samples
of 100 g soil was weighted and put it on the sieve that was on a bowl filled with water.
The upper portion of sieve was lined with three layers of kitchen tissue paper. After 5
days the nematode suspension was collected in a beaker and left for a day, excess
water was discarded leaving 100 ml suspension and 5 ml sub sample was taken and
put into a counting dish. Juveniles counting were done by using a compound
microscope (Photograph 16 and Photograph 17).
54
Photograph 15. Counting the number of egg/ eggmass (40x)
Photograph 16. Extraction of nematode by Bangladeshi plate method (modified
White Head and Heaming method, 1965)
55
Photograph 17. Second stage juveniles of Meloidogyne incognita(40x)
56
3.18. Gall index
Root galls were indexed on a 0-10 scale of Bridge and Page (1980), which were as
follows
Scales Specification
0 No galls
1 Few small gall, difficult to find
2 Small gall only, clearly visible, main root clean
3 Some larger galls visible, main root clean
4 Larger galls predominant but main root clean
5 50% of the roots infected, galling on some main roots, reduced root
system
6 Galling on main roots
7 Majority of the main roots galled
8 All main roots including tap roots galled, few clean roots visible
9 All roots severely galled, plants usually dying
10 All roots severely galled, no root system
57
3.19. Egg masses colonization (%) by Purpureocillium lilacinum
Egg masses were collected as per treatment from the eggplant plant roots, washed
with water and disinfected with a solution of 10% Clorox, rinsed with sterile water
and put on a Potato Dextrose Agar (PDA) media in petridish. Randomly ten
eggmasses/root were collected so that 80 egg masses per treatments were collected.
The number of colonized egg masses was determined after 5 days of incubation. The
presence of P. lilacinum with egg mass of M. incognita was confirmed by preparation
of slides from the culture grown on PDA (Plate 1).
A B
Plate 1. Egg colonization of M. incognita by P. lilacinum (A and B)
58
3.20. Soil colonization by Purpureocillium lilacinum (CFUg-1 soil)
Samples of 1g soil from each treatment were collected after harvest of the crop around
the root zone. The number of colony forming unit (CFUg-1 soil) per gram soil was
determined using the soil dilution plate method (Photograph 18).
Photograph 18. Determination of CFUg-1 soil using the soil dilution plate method
59
3.21. Observation of roots for mycorrhizal infection
Following Phillips and Hayman (1970) roots was treated with 10 % KOH solution for
30 min to 1-2 hours in a hot bath. Treated roots was washed with water and treated
with 2 % HCl solution. Acidified root samples were stained with 0.05 % acid fuchsin
in lactic acid for 10-15 min in a hot bath. The roots were destained with lactic acid or
lacto-glycerol. Then the destained root segments were mounted in acetic glycerol on
slides and the cover slips was placed and slightly pressed. The roots were observed
under the microscope. The presence or absence of infection of AMF in the root
segments was recorded and the percent infection was calculated using the following
formula:
Number of AMF positive segments
% Root infection = ×100
Total number of segments recorded
A root segments was considered to be infected if it showed mycelium, vesicle and
arbuscules or any other combination of AM fungi.
3.22. Study of spore population of in soil
After confirming Mycorrhizal association in the root system, we identify the spore
population in soils were isolated and inoculated. Identification was done in the Central
Laboratory of Department of Plant Pathology, SAU, Dhaka.
60
Plate 2. Observation of eggplant roots for mycorrhizal infection.
(A and B): vesicle. (C and D): Mycelium
vesicle
Mycelium
A
D
B
C
61
3.23. Chemical analysis of plant sample
3.23.1. Nutrient analysis
Chemical analysis of the plant samples was done in the department of Soil Science
and in the Department of Agricultural Chemistry, SAU, Dhaka.
3.23.2. Preparation of plant sample
Plant (shoot) samples were dried in oven at 700C for 70 hours and then ground the
samples and sufficient amount of sample for each treatment was kept in desiccators
for chemical analysis.
3.23.3. Digestion of plant samples with nitric-perchloric acid mixture
An amount of 0.5g of sub-sample was taken into a dry clean 100ml Kjeldahl flask,
10ml of di-acid mixture (HNO3, HClO4 in the ratio of 2:1) was added and kept for few
minutes. Then, the flask was heated at a temperature rising slowly to 2000C. Heating
was instantly stopped as soon as the dense white fumes of HClO4 occurred and after
cooling, 6ml of 6N HCl were added to it. The content of the flask was boiled until
they became clear and colorless. This digest was used for determining P, K and S.
3.23.4. Phosphorus
Phosphorus in the digest was determined by ascorbic acid blue color method (Murphy
and Riley, 1962) with the help of a Spectrophotometer (LKB Novaspec, 4049).
3.23.5. Potassium
Potassium content in the digested plant sample was determined by flame photometer
Sulphur content in the digest was determined by turbidimetric method as described by
Hunt (1980) using a Spectrophotometer (LKB Novaspec,4049).
62
3.23.6. Nitrogen
Plant samples were digested with 30% H2O2, conc. H2PO4 and a catalyst mixture
(K2SO4: CuSO4.5H2O: Selenium powder in the ratio of 100: 10: 1, respectively) for
the determination of total nitrogen by Micro-Kjeldahl method. Nitrogen in the digest
was determined by distillation with 40% NaOH followed by titration of the distillate
absorbed in H3BO3 with 0.01N H2SO4 (Bremner and Mulvaney, 1982).
3.23.7. Arsenic
Analysis of arsenic was conducted by following steps:
10% HCl was prepared as a carrier liquid by dilution of 100 ml conc. HCl into
1000 ml volumetric flask. Then the flask was volume upto the mark of 1000
ml.
Potassium borohydride solution was prepared by taking 7.5 g of potassium
borohydride and 0.3% sodium hydroxide in a 500 ml volumetric flask. Then
the volume of 500 ml made by adding water.
Standard arsenic solution of 0, 2.5, 7.5, 10 and 12.5 µg/L were prepared from
As2O5.
Detection of arsenic was done with Hydride Generation Atomic Absorption
Spectrophotometer (Analytik jena), an arsenic detection equipment in soil
science laboratory of Sher-e-Bangla Agricultural University. After preparation
of samples and all necessary chemicals, the equipment was operated
maintaining manufacturer’s guideline.
This equipment is a computer based, so the result was displayed on the monitor
through the respective software and the reading was taken as ppb.
3.24. Analysis of data
The data were statistically analyzed using analysis of variance to find out the variation
of results from experimental treatments. Treatment means were compared by
Duncan’s New Multiple Range Test (DMRT) according to Gomez and Gomes,
(1984).
63
RESULTS AND DISCUSSION
Arbuscular mycorrhizal fungus has the remarkable influence on plant growth, nutrient
uptake and arsenic toxicity. In arsenic contaminated soil AMF reduce the plant arsenic
uptake in contrast to uninoculated plant. This fungus triggers several channel to
bypass the arsenic during nutrient uptake thus reduce arsenic toxicity. When
artificially AMF is inoculated in arsenic amended soil, it strengthens plant to face the
adversity as a result it can tolerate the adverse situation and can grow as a healthy
plant. Due to this mechanism plant growth and nutrient uptake is increased. In this
experiment, arsenic and the nematode M. incognita challenged soil was prepared to
know the combined effect of AMF and P. lilacinum. It is well known that P. lilacinum
is a nematophagus fungi and on the other hand AMF has also some reported positive
influence on nematode control. Here sixteen treatment combinations were evaluated
all the treatments of AMF, P. lilacinum, M. incognita and arsenic to determine the
combined and individual effect of this treatments on plant growth, root-knot
development, plant nutrition and As toxicity of eggplant.
4.1. For all treatment combination
4.1.1. Shoot length
The influence of Purpureocillium lilacinum in combination with Glomus sp. on shoot
length of eggplant in arsenic amended soil challenged with Meloidogyne incognita are
presented in Table 2. The shoot length was different significantly among various
treatments (Photograph 21). The highest shoot length was recorded from treatment (G
+ Pl) followed by (C+G) and (C+Pl) which were statistically similar. The highest
shoot length for treatment (G+Pl) was 26.40 cm and for treatment (C+G) and (C+Pl)
it was 20.80 cm and 20.04 cm, respectively. Shoot length with treatment (G+As) was
18.26 cm followed by treatment (G + Pl+ Mi), (G + Pl+ As + Mi), (C) and (Pl+ Mi)
where shoot lengths were 16.06 cm, 15.74 cm, 15.10 cm and 14.50 cm, respectively.
64
The lowest shoot length 9.64 cm found from treatment (Mi + As) that was statistically
similar with treatment (C+Mi) where the shoot lengths were 9.64 cm and 9.10 cm
respectively followed by treatments with (C+As), (Pl+Mi+As), (Pl+As) and
(G+As+Mi) for shoot lengths 12.88 cm, 12.90 cm, 13.18 cm and 13.30 cm
respectively. Rao et al. (1998) reported the same result that plant height was
significantly greater in case of eggplant treated with both G. mosseae and P. lilacinus.
Mycorrhizal inoculation significantly enhanced shoot height. This was probably due
to uptake of more nutrients, which increased vegetative growth. Present findings are
in agreement with Matsubara et al. (1994). Reduction in root galling and nematode
reproduction by P. lilacinus, and induction of systemic resistance/tolerance through
an improved host nutrition or modification of mycorrhizosphere by AMF, could
possibly account for the growth and yield enhancement. In the findings of Tushar et
al. (2012), it was observed that in the pot with soil contaminated with arsenic and no
mycorrhizal inoculum, performance was very bad in terms of all aspects of growth,
whereas in the pot where mycorrhizal inoculum was added along with contaminated
soil, the performance of the plant was better.
4.1.2. Root length
The influence of Purpureocillium lilacinum in combination with Glomus sp. on root
length of eggplant in arsenic amended soil challenged with Meloidogyne incognita are
presented in Table 2. The root length was different significantly among various
treatments (Photograph 22). The highest root length (cm) was recorded from treatment
(G + Pl) followed by (C+G) which were significantly distinct from other treatments
followed by (C+Pl) which was statistically similar with (G + Pl+ Mi) and (G+As).
The highest root length for treatment (G+Pl) was 20.44 cm and for treatment (C+G)
root length was 18.44 cm. Rao et al. (1998) reported the same result that root length
was significantly greater in case of egg plants treated with both G. mosseae and P.
lilacinus. The root length with treatment (C+Pl) was 15.14 cm followed by 14.70 cm
and 14.10 cm for treatment (G + Pl + Mi) and (G+As) respectively. The lowest root
65
length 7.16 cm was found from treatment (Mi + As) that was statistically similar with
treatment (C+Mi) of 8.34 cm root length followed by 9.10 cm for treatment
(Pl+Mi+As). Mycorrhizal inoculation significantly enhanced root length in
comparison to noninoculated control. This was probably due to uptake of more
nutrients, which increased vegetative growth. Present findings are in agreement with
Matsubara et al. (1994). The findings of Xia et al. (2007) is similar with the findings
of present study. They conducted an experiment under glasshouse condition in an As-
contaminated soil and they reported arbuscular mycorrhizal (AM) fungus (Glomus
mosseae) increased root length markedly under the zero-P treatments. This validates
the synergistic interaction between the two biocontrol agents as reported earlier by
some authors (Al-Raddad, 1995; Trivedi, 1997; Rao et al. 1998; Bhat and Mahmood
2000; Sharma).
4.1.3. Shoot fresh weight
The role of Purpureocillium lilacinum in combination with Glomus sp. on shoot fresh
weight of eggplant in arsenic amended soil challenged with Meloidogyne incognita
are presented in Table 2. The result revealed that among all the treatments, the highest
fresh weight of shoot 15.51g was recorded in treatment (G + Pl) which was
remarkably different from other treatments followed by (C+G) and (C+Pl) of which
weight of shoot was 13.29g and 12.95g, respectively which were statistically similar.
The lowest fresh weight of shoot 6.34g found from treatment (C+Mi) followed by (Mi
+ As) and (Pl+ Mi + As) for 6.34g and 6.26g, respectively that was statistically similar.
Rao et al. (1998) reported the same result that shoot fresh weight was significantly
greater in case of eggplants treated with both G. mosseae and P. lilacinus. Tarafdar
and Parveen, (1996) reported that shoot biomass was significantly improved in
mycorrhiza inoculated plants.
66
Table 2. Influence of Purpureocillium lilacinum in combination with Glomus sp. on
shoot length, root length, shoot and root fresh weight of eggplant in arsenic
amended soil challenged with Meloidogyne incognita
Treatments Shoot length
(cm)
Root length
(cm)
Shoot fresh
weight (g)
Root fresh
weight (g)
C 15.10 d 12.32 ef 8.06 ghi 5.48 g
C + G 20.80 b 18.44 b 13.29 b 9.32 b
C + Pl 20.04 b 15.14 c 12.95 bc 8.18 c
C + Mi 9.640 g 8.340 ij 6.34 j 4.82 g
C + As 12.88 f 11.00 fg 7.09 ij 5.34 g
G + As 18.26 c 14.10 cd 11.70 cd 7.48 cd
Pl + As 13.18 ef 10.00 gh 8.66 fgh 5.30 g
Mi + As 9.100 g 7.160 j 6.24 j 5.19 g
G + As + Mi 13.30 ef 11.04 fg 10.06 ef 5.80 fg
Pl + Mi + As 12.90 f 9.100 hi 6.26 j 5.26 g
G + Pl + As 14.64 de 12.94 de 11.98 bcd 6.80 de
G + Pl + As +
Mi
15.74 d 12.40 ef 11.24 de 6.48 ef
G + Mi 13.44 ef 12.24 ef 9.680 f 6.80 de
G + Pl 26.50 a 20.44 a 15.51 a 11.06 a
Pl + Mi 14.50 de 11.58 ef 7.58 hij 7.36 cde
G + Pl + Mi 16.06 d 14.70 c 9.04 fg 7.56 cd
Lsd (0.05) 1.42 1.37 1.333 0.88
CV (%) 7.35 8.69 10.84 10.31
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
67
4.1.4. Root fresh weight
Table 2 shows that the results of the effect of Purpureocillium lilacinum in
combination with Glomus sp. on root fresh weight of eggplant in arsenic amended soil
challenged with Meloidogyne incognita. The result revealed that among all the
treatments, the highest fresh root weight (11.06 g) was recorded in treatment (G + Pl)
which was statistically significant from other treatments followed by treatment (C+G)
gave root weight of 9.32 g that was statistically different from treatment (C+Pl) which
gave 8.18 g root weight. The lowest fresh root weight 5.48 g was found from treatment
(C) followed by (C+Mi), (Pl+ As), (Mi + As) and (Mi + Pl+ As) which gave 4.82,
5.30, 5.19 and 5.26 g of root weight, respectively that were statistically similar. The
results of the present study coroborates with the findings of Carling and Brown (1980)
who reported that root colonization by most of the Glomus isolates significantly
increased plant root fresh weight in low fertility soil.
4.1.5. Shoot dry weight
Table 3 shows that the results of the effect of Purpureocillium lilacinum in
combination with Glomus sp. on shoot dry weight of eggplant in arsenic amended
soil challenged with Meloidogyne incognita. The result revealed that among the 16
treatments, the highest dry weight of shoot (1.91 g) was recorded in treatment (G +
Pl) that was statistically similar to treatment (C+G) which gave shoot weight of 1.73
g followed by weight of shoot 1.63 g with treatment (C+Pl) which was statistically
similar to (C+G) but different from (G+Pl) treatment. The lowest dry weight of shoot
0.94 g was recorded from treatment (Mi+As) that was statistically similar to (C+As)
that provide the dry weight of shoot of 1.10 g. Shoot dry weights were higher in
mycorrhizal than nonmycorrhizal plants is reported by Giri et al., 2005. The findings
of the present study are in accordance with the findings of Xia et al. (2007) who
reported that both of dry weight and root biomass of maize plants increased markedly
when inoculated with arbuscular mycorrhizal (AM) fungus (Glomus mosseae) under
glasshouse condition in an arsenic amended soil.
68
4.1.6. Root dry weight
Sixteen treatments were taken to evaluate the effect of Purpureocillium lilacinum in
combination with Glomus sp. on root dry weight of eggplant in arsenic amended soil
challenged with Meloidogyne incognita (Table 3). The highest dry root weight 1.76 g
was recorded in treatment (G + Pl) which was statistically similar with treatments
(C+G) which gave 1.71 g dry root weight followed by (C+Pl) from which dry root
weight was obtained 1.38 g. The results of treatment (G+Pl) and (C+G) were
statistically different from all others treatments. The lowest dry root weight (0.27 g)
found from treatments (Mi+As) followed by treatments (Pl+As), (Mi+Pl+As) and
(C+As) which provided results of 0.31 g, 0.40 g and 0.35 g for dry root weight
respectively that were statistically similar. Root dry weights were higher in
mycorrhizal than nonmycorrhizal plants is reported by Giri et al., 2005. The findings
of the present study are in accordance with the findings of Xia et al. (2007) who
reported that both of dry weight and root biomass of maize plants increased markedly
when inoculated with arbuscular mycorrhizal (AM) fungus (Glomus mosseae) under
glasshouse condition in an arsenic amended soil.
4.1.7. Leaf area
Leaf area influencd by the Purpureocillium lilacinum in combination with Glomus sp.
of eggplant in arsenic amended soil challenged with Meloidogyne incognita presented
in Table 3. The result revealed that among the 16 treatments, the highest leaf area
(18.18 cm2) was obtained from treatment (G+Pl) that was statistically different from
all other treatments followed by (C+G) that was statistically different from (C+Pl).
The leaf area found 37.64 cm2 and 34.92 cm2 from treatments (C+G) and (C+Pl)
respectively. The lowest leaf area 15.07 cm2 found from treatment (C+Mi) that was
statistically different from all other treatments followed by (Mi+As) and (C+As)
which gave leaf area of 22.27 cm2 and 24.46 cm2 respectively. As plant height, shoot
weight, root weight and root length/g of root were significantly greater so the leaf area
69
also increased accordingly due to the combined and individual effect of Glomus sp.
and P. lilacinum.
4.1.8. Chlorophyll content
Chlorophyll content influencd by the Purpureocillium lilacinum in combination with
Glomus sp. of eggplant in arsenic amended soil challenged with Meloidogyne
incognita presented in Table 3. Among the 16 treatments, the highest chlorophyll
content 42.18 μg cm−2 was recorded in treatment (G + Pl) which was significantly
different from all other treatments followed by treatments (C+G) and (C+Pl) which
provided the chlorophyll content of 39.12 μg cm−2 and 34.20 μg cm−2 respectively.
The result of treatment (C+G) and (C+Pl) was statistically different from each other
and from all other treatments. The lowest chlorophyll content 22.32μg cm−2 was
recorded from treatment (Mi + As) followed by treatment (C+As) from which 23.28
μg cm−2 chlorophyll content was obtained. All other treatments provided
significantly different results according the Table 3. Mycorrhizal infection
ameliorated chlorophyll content of lettuce reported by Zuccarini (2007). Again the
findings of Elahi et al. (2010) stated that AMF has a positive influence on chlorophyll
content. Cabanillas et al. (1989), Kiewnick and Sikora (2004) and Esfahani and Pour
(2006) reported that plant growth parameters and yield promoted by using the
bioagent P. lilacinum compared with plants treated with this nematode alone.
70
Table 3. Influence of Purpureocillium lilacinum in combination with Glomus sp. on
dry weight of shoot and root, leaf area and chlorophyll content of eggplant in
arsenic amended soil challenged with Meloidogyne incognita
Treatments Shoot dry
weight (g)
Root dry
weight (g)
Leaf area
(cm2)
Chlorophyll
content(μgcm−2)
C 1.42 cdef 0.47 f 32.54 cde 30.72 d
C + G 1.73 ab 1.71 a 37.64 b 39.12 b
C + Pl 1.63 bc 1.38 b 34.92 c 34.20 c
C + Mi 1.17 gh 0.62 e 15.07 k 25.10 f
C + As 1.10 hi 0.35 fg 24.46 ij 23.28 g
G + As 1.41 cdefg 1.38 b 29.80 fg 28.52 e
Pl + As 1.46 cde 0.31 g 29.96 efg 27.78 e
Mi + As 0.94 i 0.27 g 22.27 j 22.32 g
G + As + Mi 1.28 efgh 0.47 f 28.34 gh 31.28 d
Pl + Mi + As 1.08 hi 0.40 fg 26.23 hi 27.86 e
G + Pl + As 1.50 cde 0.79 d 30.95 efg 34.10 c
G + Pl + As +
Mi
1.39 cdefg 0.67 de 29.25 fg 28.10 e
G + Mi 1.55 bcd 1.36 b 30.75 efg 31.10 d
G + Pl 1.91 a 1.76 a 48.18 a 42.18 a
Pl + Mi 1.19 fgh 1.08 c 31.70 def 27.80 e
G + Pl + Mi 1.36 defg 1.29 b 34.11 cd 31.02 d
Lsd (0.05) 0.21 0.11 2.40 1.12
CV (%) 12.16 10.44 6.27 2.93
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
71
Photograph 19. Growth pattern of eggplant in different treatment combination
during two months of growing
72
Plate 3. Eggplant root at different treatments combination; A = C, B = C+G, C = C+Pl,
D = C+Mi, E = C+As, F = G+As, G = Pl+As, H = Mi+As, I = G+As+Mi, J = Pl+Mi+As,
K = G+Pl+As, L = G+Pl+As+Mi, M = G+Mi, N = G+Pl, O = Pl+Mi, P = G+Pl+Mi
(C= Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic)
I J L K M N P
A B C D F G H
O
E
73
4.2. For Glomus sp. involved treatment combination
4.2.1. Shoot length
Shoot length of eggplant influenced by the eight mycorrhizal treatments in different
combination of P. lilacinum, M. incognita and arsenic is shown in Fig. 1. It was found
that Glomus sp. in combination of P. lilacinum treatment (G + Pl) gave the highest
shoot length 26.50 cm which was significantly different from all other treatments
followed by (C+G) provided the shoot length of 20.80 cm. The lowest shoot length
13.30 cm was revealed from treatment (G + As + Mi) followed by treatment (G + Mi)
which gave shoot length of 13.44 cm. Udo et al. (2013) reported same findings
investigating the single and combined effects of different arbuscular mycorrhizal
fungi (AMF) and bio formulated Paecilomyces lilacinus against M. incognita race 1
on tomato. Venkatesan et al. (2013) investigated that As uptake was increased up to
three times due to the nematode infection of roots, the increase being more at the
higher inoculum level. So, the treatment (G+As+Mi) gave the lowest shoot length.
Mycorrhizal inoculation significantly enhanced shoot height and root length. This was
probably due to uptake of more nutrients, which increased vegetative growth. Present
findings are in agreement with Matsubara et al. (1998).
74
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Fig. 1. Shoot length of eggplant influenced by the eight mycorrhizal treatments in
different combination of P. lilacinum, M. incognita and arsenic
b
c
cde
d
e
a
d
0
5
10
15
20
25
30Sh
oo
t le
ngt
h (
cm)
Treatments
75
4.2.2. Root length
Fig. 2 represents that the root length of eggplant influenced by the eight mycorrhizal
treatments with different combination of P. lilacinum, M. incognita and arsenic.
Among eight mycorrhizal treatments, it was found that Glomus sp. in combination of
P. lilacinum (G+Pl) treatment provided the highest root length 20.44 cm that was
significantly different to other treatment combination followed by treatment (C+G)
which gave 18.44 cm root length. The lowest root length 11.04 cm was revealed from
treatment (G+As+Mi) that was statistically similar to treatment (G+Mi) which gave
12.24 cm root length. Arsenic uptake was increased up to three times due to the
nematode infection of roots reported by Venkatesan, et al. (2013). So, the treatment
(G+As+Mi) gave the lowest shoot length. Mycorrhizal inoculation significantly
enhanced shoot height and root length in comparison to noninoculated control. This
was probably due to uptake of more nutrients, which increased vegetative growth are
in agreement with Matsubara et al. (1998).
76
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Fig. 2. Root length of eggplant influenced by the eight mycorrhizal treatments with
different combination of P. lilacinum, M. incognita and arsenic
b
cdf
de e ef
a
c
0
5
10
15
20
25
Ro
ot
len
gth
(cm
)
treatments
77
4.2.3. Leaf area
The role of Glomus sp on leaf area of eggplant in combination of P. lilacinum in
arsenic amended soil challenged with Meloidogyne incognita is presented in Figure
3. Results revealed that treatment (G+Pl) gave highest leaf area 48.18 cm2 which
statistically significant and different from all other treatments followed by treatment
(C+G), (G+Pl+Mi) for leaf area 37.64 and 34.11 cm2, respectively. The lowest leaf
area 28.34 cm2 was revealed from treatment (G+As+Mi) followed by treatment
(G+Pl+As+Mi), (G+As), (G+Mi), and (G+Pl+As) from which leaf area obtained
29.25, 29.80, 30.75, 30.75 and 30.95 cm2, respectively where all of these treatments
results were statistically similar. Tarafdar and Parveen, (1996) reported that shoot
biomass was significantly improved in mycorrhiza inoculated plants. Again, P.
lilacinum has synergistic effect on growth parameters with AMF, so the combined
and individual presence of Glomus and P. lilacinum increased leaf area.
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Fig. 3. The role of Glomus sp on leaf area of eggplant in combination of P. lilacinum
in arsenic amended soil challenged with Meloidogyne incognita
b
d dd
dd
a
c
0
10
20
30
40
50
60
leaf
are
a (c
m2
)
Treatments
78
4.2.4. Chlorophyll content
Chlorophyll content of eggplant influenced by the role of Glomus sp in combination
of P. lilacinum in arsenic amended soil challenged with Meloidogyne incognita is
presented in Fig. 4. Among eight mycorrhizal treatments, it was found that treatment
(G+Pl) gave highest chlorophyll content 42.18 μg cm-2 of eggplant leaves which was
statistically different from all other treatments followed by treatment (C+G) provided
39.12 μg cm-2 chlorophyll content. The lowest chlorophyll content 28.10 μg cm-2 was
revealed from treatment (G+Pl+As+Mi) that was statistically similar to treatment
(G+As) that gave leaf chlorophyll content 28.52 μg cm-2. The chlorophyll is the
essential component for photosynthesis and it increases with mycorrhizal colonization
(Colla et al., 2008). AM symbiosis enhanced the chlorophyll content of Solanum
leaves which was in agreement with the results of other studies (Elahi et al., 2010;
Kapoor and Bhatnagar, 2007).
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Fig. 4. Chlorophyll content of eggplant influenced by Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne incognita
b
ed
c
e
d
a
d
0
5
10
15
20
25
30
35
40
45
Ch
loro
ph
yll c
on
ten
t (u
gcm
-2)
Treatments
79
4.2.5. Shoot fresh weight
Variation of shoot fresh weight of eggplant due to eight mycorrhizal treatments of
eggplant influenced by the role of Glomus sp in combination of P. lilacinum in arsenic
amended soil challenged with Meloidogyne incognita is shown in Figure 5. Among
these treatments, it was found that treatment (G+Pl) gave highest fresh shoot weight
15.51 g that was significantly different from all other treatments followed by treatment
(C+G) which gave 13.29 g fresh shoot weight. The lowest fresh shoot weight 9.04 g
was revealed from treatment (G+Pl+Mi) which was statistically similar to treatment
(G+Mi), (G+As+Mi) for 9.68 and 10.06 g fresh shoot weight, respectively. Since the
eggplant was grown with two reported ecofriendly organisms so their combined effect
invaded pathogen and mediated arsenic contamination. So, shoot weight increased
when they were combindly inoculated rather than uninoculated and individual
treatments combination.
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Fig. 5. Variation of shoot fresh weight of eggplant due to eight mycorrhizal treatments
of eggplant influenced by Glomus sp in combination of P. lilacinum in arsenic
amended soil challenged with Meloidogyne incognita
bbc
debc cd
de
a
e
0
2
4
6
8
10
12
14
16
18
Aer
ial f
resh
wei
ght
(g)
Treatments
80
4.2.6. Shoot dry weight
Shoot dry weight of eggplant influenced by the role of Glomus sp. in combination of
P. lilacinum in arsenic amended soil challenged with Meloidogyne incognita is
presented in Fig. 6. Among eight mycorrhizal treatments, it was found that treatment
(G+Pl) gave the highest dry shoot weight 1.91g that was statistically similar to
treatment (C+G) from which 1.73 g shoot dry weight obtained. The lowest dry shoot
weight, 1.28 g was obtained from treatment (G+As+Mi) followed by (G+Pl+As+Mi)
and (G+As) which provided 1.39 and 1.41 g shoot dry weight respectively. Present
findings validate the findings of Xia et al. (2007). They found that both of dry weight
and root biomass of maize plants increased markedly when inoculated with arbuscular
mycorrhizal (AM) fungus (Glomus mosseae) under glasshouse condition in an arsenic
amended soil. The present findings are also in accordance with the findings of Ahmed
et al. (2003).
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 6. Shoot dry weight of eggplant influenced by Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne incognita
ab
cdd
bcd cdbc
a
cd
0
0.5
1
1.5
2
2.5
Aer
ial d
ry w
eigh
t (g
)
treatments
81
4.2.7. Root fresh weight
Influence of Glomus sp. involved treatments combination on root fresh weight is
shown in Fig. 7. Results revealed that treatment (G + Pl) gave highest fresh root
weight 11.06 g that was statistically different from all other treatments followed by
treatment (C+G) from which 9.32 g root fresh weight was obtained. The lowest fresh
root weight 5.80g among eight mycorrhizal treatments was found from treatment
(G+As+Mi) which was statistically similar to (G+Pl+Mi+As), (G+Pl+As) and
(G+Mi) where 6.48, 6.80 and 6.80 g root fresh weight, respectively were obtained.
Results of the experiment confirmed various reports on enhanced plant growth due to
AM inoculation to medicinal plants (Nisha and Rajeshkumar, 2010) and forest trees
species (Rajan et al., 2000).
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 7. Root fresh weight of eggplant influenced by Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne incognita
b
c
d
cd cd cd
a
c
0
2
4
6
8
10
12
14
Fres
h r
oo
t w
eigh
t (g
)
Treatments
82
4.2.8. Root dry weight
Root dry weight of eggplant influenced by the role of Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne incognita is presented
in Figure 8. Among 8 mycorrhizal treatments, it was found that treatment (G+Pl)
provided the highest result of root dry weight 1.76 g that was statistically similar with
the effect of treatment of (C+G) which gave 1.71 g dry root weight. The lowest dry
root weight 0.47 g was revealed from treatment (G+As+Mi) which was significantly
different from all other treatments. Present findings are in accordance with Xia et al.
(2007) who reported that both of dry weight and root biomass of maize plants
increased markedly while inoculated with arbuscular mycorrhizal (AM) fungus
(Glomus mosseae) under glasshouse condition in an arsenic amended soil.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 8. Shoot dry weight of eggplant influenced by Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne incognita
ab
e
cd
ba
b
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Dry
ro
ot
wei
ght
(g)
Treatments
83
4.2.9. Number of spore of Glomus sp. /10 g soil
Influence of Glomus sp involved treatments combination on of spore of Glomus sp.
/10 g soil is shown in Fig. 9. Among 8 mycorrhizal treatments, it was found that
treatment (G+Pl) gave the highest result of 35.60 number of spore of Glomus sp. /10
g soil that was statistically similar to the result of 30.40 spore/10 g soil for treatment
(C+G). The result confirms the findings of Rao et al. (1998). The lowest result of
15.80 number of spore of Glomus sp. /10 g soil was found from treatment (G+As+Mi).
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Figure 9. Number of spore of Glomus sp. /10 g soil influenced by the role of Glomus
sp in combination of P. lilacinum in arsenic amended soil challenged with
Meloidogyne incognita
ab
cd
e
bcd bc
d
a
b
0
5
10
15
20
25
30
35
40
No
. of
spo
re/1
0 g
so
il
Treatments
84
4.2.10. Root infection by Glomus sp.
Root infection by Glomus sp. in different level of combination with P. lilacinum, M.
incognita and arsenic is represented in Fig. 10. Among eight mycorrhizal treatments,
it was found that treatment (G+Pl) gave the highest root infection of 58.30% which
was significantly different from all other treatments followed by 54.80% root
infection by the treatment (C+G). The lowest root infection 34% was found from
treatment (G+As+Mi) which was statistically dissimilar to all other treatments. The
result of the present study corroborating with the findings of Rao et al. (1998) of 64
and 62% infection in eggplant due to the combined inoculation of Glomus sp. and P.
lilacinum and individual inoculation of Glomus sp., respectively.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 10. Root infection (%) influenced by the role of Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne incognita
be
f
d ce
ade
0
10
20
30
40
50
60
70
Ro
ot
infe
ctio
n (
%)
Treatments
85
4.3. For Purpureocillium lilacinum treatments
4.3.1. Shoot length
Shoot length of eggplant influenced by the eight P. lilacinum involved treatments in
different combination with Glomus sp., M. incognita and arsenic is shown in Fig. 11.
Among eight Purpureocillium lilacinum treatments, it was found that treatment
(G+Pl) gave the highest result for shoot length 26.50 cm which was statistically
different from all other treatments followed by (C+Pl) from which 20.04 cm shoot
length was obtained. The lowest shoot length 12.90 cm was found from treatment
(Pl+Mi+As) statistically similar to the treatment (Pl+As) (Pl+Mi) and (G+Pl+As) for
shoot length of 13.18, 14.50 and 14.64 cm, respectively. Improved plant growth
characters by application of P. lilacinus in controlling root-knot nematodes was also
reported earlier by Walia et al. (1999), and Khan and Goswami (2000). So, the
Glomus effect on arsenic mediation and nematode controlling effect of P. lilacinum
marked well in aspect of shoot length.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 11. Shoot length of eggplant influenced by the eight P. lilacinum involved
treatments in different combination with Glomus sp., M. incognita and arsenic
b
dd cd c
a
cd c
0
5
10
15
20
25
30
Sho
ot
len
gth
(cm
)
Treatments
86
4.3.2. Root length
Fig. 12 represents that the root length of eggplant influenced by the eight P. lilacinum
treatments with different combination of Glomus sp., M. incognita and arsenic. It was
found that treatment (G+Pl) gave the highest root length 20.44 cm that was
remarkably different from all other treatments followed by treatment (C+Pl) gave the
root length of 15.14 cm. The lowest root length 11.58 cm was found from treatment
(Pl+Mi) statistically similar to (G+ Pl+Mi+As), (G+Pl+As) for 12.40 cm and 12.94
cm root length. This is validated by Hasan (2004), who narrated the better effect of P.
lilacinus on growth parameters.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 12. Root length of eggplant influenced by the eight P. lilacinum treatments with
different combination of Glomus sp., M. incognita and arsenic
b
dd
c c
a
c
b
0
5
10
15
20
25
Ro
ot
len
gth
(cm
)
Treatments
87
4.3.3. Leaf area
The role of P. lilacinum involved treatments on leaf area of eggplant in combination
of Glomus sp in arsenic amended soil challenged with Meloidogyne incognita is
presented in Fig. 13. Of eight P. lilacinum treatments, it was found that treatment
(G+Pl) gave the highest leaf area 48.18 cm2 that was statistically significant from all
other treatments followed by (C+Pl) from which 34.92 cm2 leaf area found. The
lowest leaf area 26.23 cm2 was found from treatment (Pl+Mi+As) statistically similar
to (G+Pl+As+Mi) for leaf area 29.25 cm2. Probably individual and combined effect
of this two bio-agent P. lilacinum and Glomus sp. contributed on healthy growth of
eggplant which triggers better leaf area.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 13. The role of P. lilacinum involved treatments on leaf area of eggplant in
combination of Glomus sp in arsenic amended soil challenged with Meloidogyne
incognita
bbcd
dbcd de
a
bc bc
0
10
20
30
40
50
60
Folia
r su
rfac
e (c
m2
)
Treatments
88
4.3.4. Chlorophyll content
Chlorophyll content of eggplant influenced by eight P. lilacinum treatments in
combination of Glomus sp. in arsenic amended soil challenged with Meloidogyne
incognita is shown in Fig. 14. Of eight P. lilacinum treatments, it was found that
treatment (G+Pl) gave the highest chlorophyll content 42.80 μg cm-2 that was
statistically different from all other treatments followed by (G+Pl+As) and (C+Pl) for
34.10 μg cm-2 and 34.20 μg cm-2 chlorophyll content. The lowest chlorophyll content
27.78 μg cm-2 was found from treatment (Pl+As) statistically similar to (Pl+Mi),
(Pl+Mi+As), (G+Pl+Mi+As) for 27.80, 27.86 and 28.10 μg cm-2 of chlorophyll
content, respectively. As P. lilacinum has been reported as soil ameliorates and which
keep the rhizosphere area safe for plant root growth as well as has synergistic relation
with Glomus sp. so the chlorophyll content increased due to their influence.
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Figure 14. Chlorophyll content of eggplant influenced by the role of eight P. lilacinum
treatments in combination of Glomus sp. in arsenic amended soil challenged with
Meloidogyne incognita
b
d d
b
d
a
dc
0
5
10
15
20
25
30
35
40
45
Ch
loro
ph
yll c
on
ten
t (u
g/cm
-2)
Treatments
89
4.3.5. Shoot fresh weight
Variation of shoot fresh weight of eggplant due to eight P. lilacinum treatments of
eggplant in combination of Glomus sp. in arsenic amended soil challenged with
Meloidogyne incognita is shown in Fig. 15. Among eight P. lilacinum treatments, it
was found that treatment (G+Pl) gave the highest fresh shoot weight 15.51 g that was
statistically different from other treatments followed by (C+Pl) from which 12.95 g
fresh shoot weight was obtained. The lowest fresh shoot weight 6.26 g was found from
treatment (Pl+Mi+As) that was statistically similar to the treatment of (Pl+Mi) for
shoot fresh weight 7.58 g. Though the presence of M. incognita and arsenic
contamination decreased the shoot weight but when P. lilacinum present in the
treatment combination with M. incognita, due to its nematophagous properties,
increased the normal plant growth in combination with Glomus sp.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 15. Variation of shoot fresh weight of eggplant due to eight P. lilacinum
treatments of eggplant influenced by the role of P. lilacinum in combination of
Glomus sp in arsenic amended soil challenged with Meloidogyne incognita
b
de
f
bc c
a
ef
d
0
2
4
6
8
10
12
14
16
18
Aer
ial f
resh
wei
ght
(g)
Treatments
90
4.3.6. Shoot dry weight
Shoot dry weight of eggplant influenced by P. lilacinum related treatments in
combination of Glomus sp in arsenic amended soil challenged with Meloidogyne
incognita is presented in Fig. 16. Among eight P. lilacinum treatments, the highest
result for dry shoot weight 1.91 g was found from the treatment (G+Pl) which was
significantly different from all other treatments followed by (C+Pl) that gave 1.63 g
dry shoot weight. The lowest dry shoot weight 1.08 g was found from treatment
(Pl+Mi+As) that was statistically similar to the treatment of (Pl+Mi) for 1.19 g shoot
dry weight. P. lilacinum gave better plant growth in the experiment of Davide et al.
(1987) which confirms our study viz. when P. lilacinum was in combination of
Glomus the growth parameters projected better results.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 16. Shoot dry weight of eggplant influenced by P. lilacinum related treatments in
combination of Glomus sp in arsenic amended soil challenged with Meloidogyne
incognita
ab
cdd
bcd cdbc
a
cd
0
0.5
1
1.5
2
2.5
Aer
ial d
ry w
eigh
t (g
)
treatments
91
4.3.7. Root fresh weight
Influence of P. lilacinum involved treatments combination on root fresh weightis
shown in Fig. 17. Results revealed that treatment (G+Pl) gave the highest fresh root
weight 11.06 g that was statistically different from all other treatments followed by
the treatment (C+Pl) gave result of 8.18 g. The lowest fresh root weight 5.26 g was
found from treatment (Pl+Mi+As) that was statistically similar to (Pl+ As) for 5.30 g
root fresh weight. P. lilacinum significantly increased root weights and other growth
characteristics in line with Gomathi et al. (2006) in brinjal. P. lilacinum provided
positive impact in combination with the Glomus sp.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 17. Root fresh weight of eggplant influenced by P. lilacinum related treatments
in combination of Glomus sp. in arsenic amended soil challenged with Meloidogyne
incognita
b
d dc c
a
bc bc
0
2
4
6
8
10
12
14
Fres
h r
oo
t w
eigh
t (g
)
Treatments
92
4.3.8. Root dry weight
Root dry weight of eggplant influenced by eight P. lilacinum involved treatments in
combination of Glomus sp in arsenic amended soil challenged with Meloidogyne
incognita is presented in Fig. 18. Of all the P. lilacinum treatments, treatment (G+Pl)
gave the highest dry root weight 1.76g compared to other treatment that was
statistically different from all other treatments followed by the treatments (C+Pl) for
1.38 g root dry weight. The lowest dry root weight 0.31 g was found from treatment
(Pl+As) that was statistically similar to the treatment (Pl+Mi+As) for root dry weight
0.40 g. This result is in support to the reports of Pandey and Dwivedi (2001) and
Dhawan et al. (2004) who recorded maximum root weight in P. lilacinus applied
treatment. Since both of two bio-agents have synergistic effect on each other so they
provided better dry weight in different individual and combined treatment.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 18. Root dry weight of eggplant influenced by P. lilacinum related treatments in
combination of Glomus sp in arsenic amended soil challenged with Meloidogyne
incognita
b
ec
d d
a
c
b
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Dry
ro
ot
wei
ght
(g)
Treatments
93
4.3.9. Soil colonization by P. lilacinum (CFU/g soil)
Influence of P. lilacinum in different combination with Glomus sp. in arsenic amended
soil challenged with Meloidogyne incognita on CFU/ g soil is shown in Fig. 19.
Among this P. lilacinum treatments, the highest obtained CFU 40.20 per gram soil
was from the treatment (G+Pl) that was statistically similar to the result of the
treatment (C+Pl) for 37.80 CFU/g soil. The lowest result was found from treatment
(Pl+Mi+As) with 14.80 CFU/ g soil. Lowest result from treatment (Pl+Mi+As) was
found may be due to the presence of M. incognita and arsenic combindly which
probably deteriorated the effect of P. lilacinum.
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Fig. 19. Influence of P. lilacinum in different combination with Glomus sp. in arsenic
amended soil challenged with Meloidogyne incognita on CFU/ g soil in dilution of
(1:1000)
a
cd
dcd
bc
a
bb
0
5
10
15
20
25
30
35
40
45
CFU
(1
0 4
) /g
so
il
Treatments
94
4.4. For P. lilacinum and M. incognita parallel treatments
4.4.1. Gall index
Gall index of eggplant influenced by P. lilacinum is shown in Fig. 20. Effect of P.
lilacinum on gall index was found highest in treatment (Pl+Mi+As) of 3.26 that was
statistically distinct from other treatments. The lowest gall index was found from the
treatment (G+Pl+Mi) that was statistically similar to (Pl+Mi) and (G+Pl+Mi+As) for
1.04, 1.50 and 1.50 gall index, respectively. The findings of the present study were
supported by the findings of Kiewnick et al. (2011). They reported the fungal bio-
control agent, P. lilacinus strain with the lowest dose of 2×105 CFU/g soil was already
sufficient to reduce root galling by 45%. Application of bioformulated P. lilacinus
significantly reduced root galling. This result confirms the report of Oclarit and
Cumagun (2009) and Khalil et al. (2012) that P. lilacinus is an effective biocontrol
agent of M. incognita against tomato.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Figure 20. Gall index of eggplant influenced by P. lilacinum
a
b
b
b
0
0.5
1
1.5
2
2.5
3
3.5
4
Gal
l in
dex
treatments
95
4.4.2. Number of eggmass/ root
Role of P. lilacinum on the number of eggmass/ root was represented in Fig. 21.
The lowest number of eggmass/ root was 5.80 at the treatment of (G+Pl+Mi) that
was statistically different from all other treatments. The highest number of eggmass/
root 13.6 was found from the treatment (Pl+Mi+As) that was statistically distinct
from all other combination of the P. lilacinum and M. incognita combined
treatment. The findings of the present study were supported by the findings of
Kiewnick et al. (2011). They reported the fungal bio-control agent, P. lilacinus
strain with the lowest dose of 2×105 CFU/g soil was already sufficient to reduce
number of egg masses by 69%. Application of bioformulated P. lilacinus
significantly reduced root galling and egg production by the nematode species. This
result validates the report of Oclarit and Cumagun (2009), and Khalil et al. (2012)
that P. lilacinus is an effective biocontrol agent of M. incognita against tomato.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 21. Role of P. lilacinum on the number of eggmass/ root
a
bb
c
0
2
4
6
8
10
12
14
16
Eggm
ass/
roo
t
Treatments
96
4.4.3. Number of egg/ eggmass
Figure 22 shows that the effect of P. lilacinum on the number of M. incognita egg/
eggmass. The effect of P. lilacinum on the highest number of egg/ eggmass 297.4 was
found highest in the treatment of (Pl+Mi+As) that was statistically different from all
other treatments. The lowest number of egg/ eggmass 164.0 was found from the
treatment of (G+Pl+Mi) which was statistically different from all other treatments.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 22. Effect of P. lilacinum on the number of M. incognita egg/ eggmass
a
b bc
0
50
100
150
200
250
300
350
Egg
No
./eg
gmas
s
Treatments
97
4.4.4. Eggmass colonization
Role of P. lilacinum on the number of eggmass colonization was represented in Fig.
23. Effect of P. lilacinum on eggmass colonization was found the highest (37.80%) in
the treatment of (G+Pl+Mi) that were differed significantly from all other treatments.
The lowest eggmass colonization was 22.70% found from the treatment (Pl+Mi+As)
that was also statistically significant from all other treatments. Aminuzzaman and Liu
(2011) reported more than 80% egg parasitism and 52% juvenile mortality of
Meloidogyne spp. by Paecilomyces lilacinus. Our results are in agreement with earlier
findings of Santos et al. (1992) who observed the variations of P. lilacinus for egg
parasitism on M. incognita.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 23. Role of P. lilacinum on the number of eggmass colonization
d
c b
a
0
5
10
15
20
25
30
35
40
45
Eggm
ass
colo
niz
atio
n
Treatments
98
4.4.5. Reproduction factor
Of all the P. lilacinum treatments, four treatments were in combination of M. incognita
and the influence of P. lilacinum on the reproduction factor for nematode is shown in
Fig. 24. P. lilacinum on reproduction factor of M. incognita was found the lowest in
the treatment of (G+Pl+Mi), where the reproduction factor was lowest 1.85 which was
statistically different from all other treatments. The highest reproduction factor 5.39
was found from the treatment of (Pl+Mi+As). This result was in agreement with the
findings of Udo et al. (2013). Park et al. (2004) reported the production of
leucinotoxin and other nematicidal compounds by P. lilacinus. The overall effect was
the decrease in population and pathogenicity of the nematode species.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 24. Role of P. lilacinum on reproduction factor of M. incognita
a
b b
c
0
1
2
3
4
5
6
Rep
rod
uct
ion
fac
tor
Treatments
99
4.5. For Meloidogyne incognita involved treatments
4.5.1. Number of eggmass/root
Number of eggmass/ root of M. incognita influenced by the effect of Glomus sp in
combination of P. lilacinum in arsenic amended soil is presented in Fig. 25. Among
eight M. incognita involved treatments, the highest eggmass/ root 65.50 was found
from the treatment (C+Mi) that was significantly different from all other treatments
followed by (Mi+As) which gave 30.80 eggmass/ root. The lowest number of
eggmass/ root 5.80 was obtained from treatment (G+Pl+Mi) that was also
significantly different from all other treatments followed by the treatments (Pl+Mi)
and (G+Pl+As+Mi) for 8.80 and 9.80 eggmass/ root respectively. This result validates
the report of Oclarit and Cumagun (2009) and Khalil et al. (2012) that P. lilacinus is
an effective biocontrol agent of M. incognita against tomato.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 25. Number of eggmass/ root of M. incognita influenced by the effect of Glomus
sp. in combination of P. lilacinum in arsenic amended soil
a
b
c
ef
d
fg
0
10
20
30
40
50
60
70
Eggm
ass/
ro
ot
Treatments
100
4.5.2. Gall index
Gall index of M. incognita influenced by the role of P. lilacinum and Glomus sp. in
arsenic amended soil challenged with Meloidogyne incognita is shown in Fig. 26.
Among eight Meloidogyne incognita involved treatments, the highest gall index 6.52
was found from the treatment (C+Mi) that was significantly different from all other
treatments followed by gall index for treatment of (Mi+As). The lowest gall index
1.04 was obtained from treatment (G+Pl+Mi), statistically similar to the gall index
1.50 and 1.50 for the treatment of (Pl+Mi) and (G+Pl+Mi+As), respectively. Nicolás,
et al. (2014) worked on the effect of Glomus intraradices on tomato plants inoculated
with the nematode at transplanting. He found the use of AMF favored tomato biomass
and reduced the number of galls and reproduction factor on the plants inoculated with
the nematode at transplanting.
C= Control, G= Glomus, Pl= P. lilacinum, Mi= M. incognita, As= Arsenic
Fig. 26. Gall index of M. incognita influenced by the role of P. lilacinum and Glomus
sp. in arsenic amended soil challenged with Meloidogyne incognita
a
b
ccd
e
d
e
e
0
1
2
3
4
5
6
7
8
Gal
l in
dex
Treatments
101
4.5.3. Number of egg/ eggmass
Fig. 27 shows that the results of the number of egg/ eggmass of M. inconita on
different combination with P. lilacinum and Glomus sp. in arsenic amended soil
challenged with Meloidogyne incognita. Of all M. incognita involved treatments, the
highest number of egg/ eggmass (480.6) was found from the treatment (C+Mi) that
was statistically different from all other treatments followed by the number of egg/
eggmass (330.2) from the treatment of (G+Mi). The lowest number of egg/ eggmass
164.0 was revealed from the treatment (G+Pl+Mi) that was statistically different from
all other treatments followed by the number of egg/ eggmass 190.4 for the treatment
(Pl+Mi+As). The other treatments also gave significantly different number of egg/
eggmass for different combination of the treatments. Since both the bio-agents have
the antagonistic effect against M. incognita, might be their combined effect
synergistically boosted the reduction of Number of egg/eggmass.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 27. Number of egg/ eggmass of M. incognita on different combination with P.
lilacinum and Glomus sp. in arsenic amended soil challenged with Meloidogyne
incognita
a
ce d
f
b
fg
0
100
200
300
400
500
600
No
. of
egg/
eggm
ass
Treatments
102
4.5.4. Reproduction factor
Reproduction factor of M. incognita influenced by the effect of Glomus sp. in
combination of P. lilacinum in arsenic amended soil is presented in figure28. Among
eight M. incognita involved treatments, the highest reproduction factor 14.4 was
found from the treatment (C+Mi) that was significantly different from all other
treatments followed by (Pl+Mi+As) which gave 5.39 reproduction factor. The lowest
reproduction factor 1.85 was obtained from treatment (G+Pl+Mi) that was also
significantly different from all other treatments followed by the treatments (Pl+Mi),
(G+Pl+As+Mi) and (Mi+As) for 3.09, 3.14 and 3.42 reproduction factor, respectively.
Nicolás, et al. (2014) worked on the effect of Glomus intraradices on tomato plants
inoculated with the nematode at transplanting. He found the use of AMF favored
tomato biomass and reduced the number of galls and reproduction factor on the plants
inoculated with the nematode at transplanting.
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
Fig. 28. Reproduction factor of M. incognita influenced by Glomus sp. in combination
of P. lilacinum in arsenic amended soil
a
dc
b
d
c
d
e
0
2
4
6
8
10
12
14
16
Rep
rod
uct
ion
fac
tor
Treatments
103
4.5.5. Nutrient uptake
Nutrient uptake influencd by the Purpureocillium lilacinum in combination with
Glomus sp. on shoot of eggplant in arsenic amended soil challenged with Meloidogyne
incognita presented in Table 4. The result revealed that among the 16 treatments, the
highest nutrient uptake was recorded in treatment (G + Pl) and those were 0.48 ppm
P, 0.62 ppm K, 3.10 ppm S in shoot which was significantly different from all other
treatments. It was conspicuously observed that with the arsenic toxicity, nutrient
uptake decreases. The lowest P uptake was found from the treatment (Pl + Mi + As)
that was statistically similar with (Pl + As) and (Mi + As). The lowest K uptake was
found from treatment (C + Mi) that was statistically similar to the result of treatment
(Mi + As). Again, the lowest S uptake was recorded in treatment in (C + As) which
was statistically similar with the treatment (Mi + As). Findings indicate that the
treatment combination with the arsenic and M. incognita decreases the nutrient
uptake. It was observed from the analysis, nutrient uptake (N, P, K, S) was increased
in the treatment combination of arbuscular mycorrhizal fungus (Glomus sp.).
Mycorrhizae inoculated treatment increased the nutrient uptake significantly in
contrast to other treatments. The best treatment combination was found (G+Pl) where
when Glomus sp. and P. lilacinum was combinedly inoculated to the soil. Moreover,
the treatment combination with the Glomus sp. increased the nutrient uptake rather
than the without-Glomus sp. treatment combination. The present results have the
similarity with the findings of Al-Amri (2013) who reported that AM inoculated
Broadbean plants had higher shoot and root, and N, P, K content than non-AM plants.
In his experiment, broad bean plants grown in wastewater contaminated soil. AM
broad bean plants had higher shoot and root P, N and K contents than nonAM plants.
104
Table 4. Influence of Purpureocillium lilacinum in combination with Glomus sp. on
phosphorus, potassium and Sulphur percentage of shoot of eggplant in arsenic
amended soil challenged with Meloidogyne incognita
Treatments Shoot
N (%) P (%) K (%) S (%)
C 1.00 g 0.25 de 0.17 gh 0.61 h
C + G 1.63 b 0.40 b 0.55 b 2.39 b
C + Pl 1.24 de 0.31 c 0.50 c 1.90 c
C + Mi 0.86 h 0.21 ef 0.12 i 0.43 i
C + As 0.80 hij 0.20 f 0.17 gh 0.33 i
G + As 1.52 c 0.38 b 0.37 e 1.55 d
Pl + As 0.76 ij 0.19 f 0.19 g 0.63 h
Mi + As 0.84 hi 0.21 ef 0.15 hi 0.42 i
G + As + Mi 1.29 d 0.32 c 0.50 c 1.02 f
Pl + Mi + As 0.74 j 0.18 f 0.24 f 0.45 i
G + Pl + As 1.58 bc 0.39 b 0.45 d 1.22 e
G + Pl + As + Mi 1.12 f 0.28 cd 0.35 e 0.92 fg
G + Mi 1.24 de 0.31 c 0.21 fg 0.88 g
G + Pl 1.92 a 0.48 a 0.62 a 3.10 a
Pl + Mi 0.77 ij 0.19 f 0.36 e 0.58 h
G + Pl + Mi 1.19 ef 0.29 c 0.24 f 0.67 h
CV (%) 5.35 5.35 7.92 3.75
C = Control, G = Glomus, Pl = P. lilacinum, Mi = M. incognita, As = Arsenic
105
Giri et al. (2005) assessed the effect of two arbuscular mycorrhizal (AM) fungi,
Glomus fasciculatum and G. macrocarpum on shoot and root dry weights and nutrient
content of Cassia tora in a semi-arid wasteland soil. The concentration of P, K, Cu,
Zn and Na was significantly higher in AM inoculated seedlings than non-inoculated
seedlings.
Mycorrhizal inoculation reduced the arsenic (As) concentration in shoots. This study
shows that among the eight arsenic involved treatment combinations when Glomus
sp. and P. lilacinum combinedly present in the treatment of (G+Pl+As) the nutrient
uptake was better than their individual combination with arsenic. This findings
supported by the experiment of Elahi et al. (2010) who evaluated the influence of
AMF inoculation on growth, nutrient uptake, arsenic toxicity and chlorophyll content
of eggplant grown in arsenic amended soil. The findings of the study indicated that
AMF inoculation not only reduces arsenic toxicity but also can increase growth and
nutrient uptake of eggplant shoot. Less arsenic content and higher chlorophyll and
nutrient uptake were recorded in mycorrhiza inoculated plants in compare to non-
inoculated plants. The findings emphasized that AMF inoculation reduced arsenic
translocation from soil to plant and increase growth and nutrient uptake and
chlorophyll content of eggplant.
The treatment combination of arsenic (As) and M. incognita reduced the nutrient
uptake of roots and shoots. This higher nutrient uptake in mycorrhizal plants might
be attributed to the contribution of fungal external mycelia which explore a large
volume of soil and thus absorb more nutrients (Gupta and Janardhanan, 1991).
Previous report showed that arbuscular mycorrhizal fungi increase plant uptake of
phosphate (Bolan, 1991).
106
4.5.6. Arsenic uptake
Arsenic uptake by shoot of eggplant influenced by Glomus sp in combination of P.
lilacinum in arsenic amended soil challenged with Meloidogyne incognita is presented
in Fig. 4. Among eight arsenic involved treatments, it was found that treatment
(G+Pl+As) gave lowest amount arsenic uptake 29.30 ppb of eggplant which was
statistically different from all other treatments followed by treatment (C+G). The
highest amount of arsenic uptake was recorded from treatment (C+As) ie. 60.70 ppb
which was statistically different from all other treatments. AMF can essentially
improve plant mineral nutrition and plant water relations (Li et al., 2014), and enhance
plant resistance to heavy metal contaminations (Hildebrandt et al., 2007). Recent
studies show that the arbuscular mycorrhizas naturally occur in As-contaminated soils
(Smith et al., 2010) and mycorrhizal inoculation can improve the As tolerance of
tomato (Liu et al., 2005b), maize (Bai et al., 2008) which corroborated to the present
findings.
Figure 29. Arsenic uptake by shoot of eggplant influenced by Glomus sp in
combination of P. lilacinum in arsenic amended soil challenged with Meloidogyne
incognita
a
fe
c c
b
g
d
0
10
20
30
40
50
60
70
Co
nce
ntr
atio
n (
pp
b)
Treatments
107
SUMMARY AND CONCLUSION
The serious arsenic contamination of groundwater in Bangladesh has come out
recently as the biggest natural calamity in the world. The people in 59 out of 64
districts comprising 126,134 km2 of Bangladesh are suffering due to the arsenic
contamination in drinking water. From a major review of studies conducted in
Bangladesh, and elsewhere in Asia, the report concludes that people may be exposed
to arsenic not only through drinking water, but indirectly though food crops irrigated
by contaminated groundwater. A number of studies have also reported a correlation
between arsenic in soil and reduction in crop yield.
This experiment was conducted to determine the influence of Glomus sp. and P.
lilacinum on growth of eggplant in arsenic amended soil challenged with M.
incognita. The investigation of results showed significant difference among
treatments in response to several combination of treatment. Of all treatments, the
highest shoot length, root length, fresh weight of shoot and root was found from
treatment (G+Pl) that was 26.50, 20.44, 15.51 and 11.06 cm, respectively. The lowest
shoot length (9.64 cm) and root length (7.16 cm) found from treatment (Mi + As) that
was statistically similar to treatment (C+Mi). Fresh weight of shoot found lowest
6.34g from treatment (C+Mi) followed by (Mi + As). The lowest fresh root weight
5.48 g was found from treatment (C) followed by (C+Mi), (Pl+ As) and (Mi + As)
which gave 4.82, 5.30g and 5.19g, respectively. Dry weight of shoot (0.94 g) and root
(0.27 g) that was recorded lowest from treatment (Mi+As) that was statistically similar
to the treatment (C+As) and (Mi+As), respectively. The highest dry weight of shoot
and root, leaf area and chlorophyll content of eggplant was revealed from treatment
(G+Pl) that was 1.91 g, 1.76 g, 48.18 cm2 and 42.18 μgcm-2, respectively. The lowest
leaf area 15.07 cm2 found from treatment (C+Mi) that was statistically different from
all other treatments followed by (Mi+As) and (C+As) which gave leaf area of 22.27
108
cm2 and 24.46 cm2, respectively. And the chlorophyll content 22.32 μg cm-2 was
recorded lowest from treatment (Mi + As).
Influence of Glomus sp. involved treatments combination on number of Glomus
spore/10 g soil and root infection shown that treatment (G+Pl) gave highest result. Of
eight AMF involved treatments 35.60 number of Glomus spore/10g soil and 58.30%
of root infection was recorded highest from treatment (G+Pl). The lowest root
infection and number of spore/10g soil found 34% and 15.80, respectively from
treatment (G+As+Mi).
Influence of P. lilacinum in different combination with Glomus sp. in arsenic amended
soil challenged with Meloidogyne incognita on CFU/ g soil is obtained highest 40.20
per gram soil from treatment (G+Pl) that was statistically similar with the result of the
treatment (C+Pl) for 37.80 CFU/g soil. The lowest CFU/ g soil was found from
treatment (Pl+Mi+As) with 14.80 CFU/ g soil.
Gall index, number of eggmass/ root, number of egg/ eggmass and reproduction factor
of M. incognita influenced by the role of P. lilacinum found lowest in treatment
(G+Pl+Mi) that was 1.04, 5.80, 164.0 and 1.85 respectively. On the other hand, the
highest gall index (6.52), number of eggmass/ root (65.60), number of egg/ eggmass
(480.6) and reproduction factor (14.4) was revealed from treatment (C+Mi). Eggmass
colonization of M. incognita found highest, 37.80% by the influence of Glomus sp.
and P. lilacinum involved treatment combination (G+Pl+Mi). The lowest eggmass
colonization was 22.70% found from the treatment (Pl+Mi+As) that was also
statistically significant from all other treatments.
109
The result revealed that among the 16 treatments, the highest nutrient uptake was
recorded in treatment (G + Pl) and those were 0.48% P, 0.62% K, 3.10% S in shoot
which was significantly different from all other treatments. It was observed that with
the arsenic toxicity, nutrient uptake decreases. The lowest P uptake 0.18% was found
from the treatment (Pl + Mi + As) that was statistically similar to (Pl + As) and (Mi +
As) for 0.19 and 0.21 % respectively. The lowest K uptake 0.12% was found from
treatment (C + Mi) that was statistically similar to the result of treatment (Mi + As)
for 0.15%. For S uptake, the lowest amount of uptake was 0.33% found from treatment
(C+As) that was statistically similar to (Pl+Mi+As) and (Mi+As).
Among eight arsenic involved treatments, it was found that treatment (G+Pl+As) gave
lowest amount arsenic uptake 29.30 ppb of eggplant which was statistically different
from all other treatments followed by treatment (C+G). The highest amount of arsenic
uptake was recorded from treatment (C+As) ie. 60.70 ppb which was statistically
different from all other treatments.
It is now recognized that AM fungi and Purpureocillium lilacinum can be harnessed
in order to improve productivity in agriculture by reducing the input of fertilizers
and/or by enhancing plant survival, thus offsetting ecological and environmental
concerns. AMF helps plant in nutrient uptake, reducing arsenic toxicity as well as
reducing plant diseases and insect attack through induced resistance. On the other
hand, P. lilacinum and AMF both have the management effect on M. incognita in
eggplant. (G+Pl) treatment can be recommended in the M. incognita infested and
arsenic contaminated soil of Bangladesh. In future the different species of Glomus
need to be considered in combination with different doses of P. lilacinum for
specification of treatment. As a result, this research will be a platform which will
minimize the farmers concern of expenditure for pesticide and fertilizer and also will
ensure the sustainable agriculture.
110
REFERENCES
Abdullahi, R. and Sheriff, H. H. (2013). Effect of arbuscular mycorrhizal fungi and
chemical fertilizer on growth and shoot nutrients content of onion under field
condition in Northern Sudan Savanna of Nigeria. J. Agril. Vet. Sci., 3: 85-90.
Adriano-Anaya, M. L., Gutiérrez-Miceli, F. A., Dendooven, L. and Salvador-
Figueroa, M. (2011). Biofertilization of banana (Musa spp. L.) with free-living
N2 fixing bacteria and their effect on mycorrhization and the nematode
Radopholus similis. J. Agril. Biot. Sustain. Dev., 3 (1): 1.
Aggangan, N. S., Tamayao, P. J. S., Aguilar, E. A., Anarna, J. A. and Dizon, T. O.
(2013). arbuscular mycorrhizal fungi and nitrogen fixing bacteria as growth
promoters and as biological control agents against nematodes in tissue-cultured
banana var. Lakatan. Philippine J. Sci., 142 (2):153-165.
Aggarwal, A., Kadian, N., Tanwar, A., Yadav, A. and Gupta, K. K. (2011). Role of
arbuscular mycorrhizal fungi (AMF) in global sustainable development. J.
Appl. Nat. Sci., 3 (2): 340-351.
Agrios, G. N. (1988). Plant Pathology, 3rd. Academic Press. Inc. New York, 803.
Ahmed, F. S., Killham, K., and Alexander, I. (2006). Influences of arbuscular
mycorrhizal fungus Glomus mosseae on growth and nutrition of lentil irrigated
with arsenic contaminated water. Plant and Soil, 283 (1-2): 33-41.
Ahmed, H. U. and Hossain, M. (1985). Crop disease survey and establishment of
herbarium at BARI. Final report of the project (1982-85), Plant Pathology Div.,
BARI, Joydebpur, Gazipur. P. 107.
Akhtar, M. S. and Siddiqui, Z. A. (2008). Arbuscular mycorrhizal fungi as potential
bioprotectants against plant pathogens. In Mycorrhizae: Sustain. Agril.
Forestry (pp. 61-97).
111
Akhtar, M. and Siddiqui, Z. (2009). Effects of phosphate solubilizing microorganisms
and Rhizobium sp. on the growth, nodulation, yield and root-rot disease
complex of chickpea under field condition. African J. Biot., 8 (15).
Akond, M. A., Mubassara, S., Rahman, M. M., Alam, S. and Khan, Z. U. (2008).
Status of vesicular-arbuscular (VA) mycorrhizae in vegetable crop plants of
Bangladesh. World J. Agril. Sci., 4(6): 704-708.
Al Agely, A., Sylvia, D. M., and Ma, L. Q. (2005). Mycorrhizae increase arsenic
uptake by the Hyperaccumulator Chinese Brake Fern (L.). J. Env. Qual., 34(6):
2181-2186.
Ali, M., Alam. M. Z. and Akanda, M. A. M. (1994). A technique of control soil borne
diseases of tomato and eggplant. IPSA-JICA publication No. 4. Institute of
Postgraduate Studies in Agriculture (IPSA), Gazipur-1703. Bangladesh. P. 10.
Al-Raddad, A.M., 1995. Interaction of Glomus mosseae and Paecilomyces lilacinus
on Meloidogyne javanica of tomato. Mycorrhiza, 5(3): 233-236.
Ambo, P. B. N., Ethiopia, E. A., Serfoji, P., Rajeshkumar, S. and Selvaraj, T. (2010).
Management of root-knot nematode, Meloidogyne incognita on tomato cv Pusa
Ruby. by using vermicompost, AM fungus, Glomus aggregatum and
mycorrhiza helper bacterium, Bacillus coagulans. J. Agril. Tech., 6 (1): 37-45.
Aminuzzaman, F. M. (2009). Biological control of root knot nematodes. Postdoctoral
Dissertation, Institute of Microbiology, Chinese Academy of Science, Beijing,
P. R. China.
Aminuzzaman, F. M. and Liu, X. Z. (2011). Biological control potentiality of
Paecilomyces lilacinus newly recorded from Bangladesh. TWAS ROESEAP-
UB symposium on industrial biotechnology towards a bio based economy of
developing countries, August 26-30. Beijing, China. p. 63.
Anastasiadis, I. A., Giannaku, I. O., Prophetou-Athanasiadou, D. A. and Gowen, S.
R. (2008). The combined effect of the application of a biocontrol agent
Paecilomyces lilacinus with various practices for the control of root knot
nematodes. Crop Prot., 27(3-5): 352-361.
112
Anwar and Van Gundy S. D., (1989). Influence of four nematodes on root and shoot
growth parameters in grapes. J. Nematol, 21: 276283.
Anwar S. A., Mckenry M. V. and Legari A. U. (2009). Host suitability of sixteen
vegetable crop genotypes for Meloidogyne incognita. J. Nematol, 41: 64-65.
Atkins, S. D., Clark, I. M., Pande, S., Hirsch, P. R., and Kerry, B. K. (2005). The use
of real-time PCR and species-specific primers for the identification and
monitoring of Paecilomyces lilacinum, FEMS Microbiol. Eco, 51:257-264.
Augé, R. M. (2004). Arbuscular mycorrhizae and soil/plant water relations. Canadian
J. Soil Sci., 84(4): 373-381.
Azcon-Aguilar, C., Jaime-Vaga, M.C. and Calvet, C. (2002). The contribution of
arbuscular mycorrhizal fungi to the control of soil-borne plant pathogens, in:
Gianinazzi, S., Schuepp, H., Barea, J.M., Haselwandeter, K. (eds), Mycorrhizal
technology in Agriculture: from genes to bioproducts, Birkhauser Verlag,
Switzerland.pp. 187-197.
Bai, J., Lin, X., Yin, R., Zhang, H., Junhua, W., Xueming, C. and Yongming, L. 2008.
The influence of arbuscular mycorrhizal fungi on As and P uptake by maize
(Zea mays L.) from As-contaminated soils. Appl. Soil Ecol., 38(2): 137-145.
Banuelos, J., Alarcón, A., Larsen, J., Cruz-Sánchez, S. and Trejo, D. (2014).
Interactions between arbuscular mycorrhizal fungi and Meloidogyne incognita
the ornamental plant Impatiens balsamina. J. Soil Sci. Plant Nutri., 14(1): 63-
74.
Barea, j. M., Azcon-Aguilar, C. and Azcon, R. (1997). Interactions between
mycorrizal fungi and rhizosphere micro-organisms within the context of
sustainable soil-plant system. In: Gange, A.C., Brown, V.K., (eds),
Multitrophic interactions in terrestrial system, Blackwell Scienc, Oxford,
UK.pp.65-77.
113
BBS, (2011). Year book of Agricultural Statistics of Bangladesh. Statistics Division,
Bangladesh bureau of Statistics (Monthly Statistical bulletin, Bangladesh,
December 2003). Ministry of Planning, Government of the peoples Republic
of Bangladesh. p. 55.
Beltrano, J., Ruscitti, M., Arango, M. C. and Ronco, M. (2013). Effects of arbuscular
mycorrhiza inoculation on plant growth, biological and physiological
parameters and mineral nutrition in pepper grown under different salinity and
p levels. J. Soil Sci. Plant Nutria.,13(1): 123-141.
Bhalerao, S. A. (2013). Arbuscular mycorrhizal fungi: a potential biotechnology tool
for phytoremediation of heavy metal contaminated soils. Inl. J. Sci. Nat.,4(1):
1-15.
Bhat M.S. and Mahmood I. 2000. Role of Glomus mosseae and Paecilomyces
lilacinus in the management of root-knot nematode on tomato. Arch.
Phytopathol. Plant Prot. 33 (2): 131–140.
Bolan NS (1991). A critical review on the role of mycorrhizal fungi in the uptake of
phosphorus by plant. Plant Soi.l, 134: 189–207.
Bonifacio, E., Nicoltotti, G., Zanini, E. and Cellerino, G.P. (1999). Heavey metal
uptake by mycorrizae of beech in contaminated and uncontaminated soils.
Fresenius Environ. Bull. 7: 408-413.
Bose T. K. and Som M. G. (1986). Vegetable crops in India. 1st Edn. Naya Prakash.
Kalkata. pp. 262-264.
Bremner, J. M., and Mulvaney, C. S. (1982). Nitrogen-total. Methods of soil analysis.
Part 2. Chemical and microbiological properties, (methodsofsoilan2). 595-
624.
Bridge, J. and Page, S. L. J. (1980). Estimation of root-knot nematode infestation
levels on roots using a rating chart. Tropical Pest Managements 26: 296-298.
Brundrett, M. C. and Abbott, L. K. (1994). Mycorrhizal fungus propagules in the
jarrah forest. New Phytologist, 127(3): 539-546.
114
Bücking, H., Liepold, E., and Ambilwade, P. (2012). The role of the mycorrhizal
symbiosis in nutrient uptake of plants and the regulatory mechanisms
underlying these transport processes. INTECH Open Access Publisher.
Budi, S. W., Blal, B. and Gianinazzi, S. (1999). Surface-sterilization of Glomus
mosseae spiorocarps for studying endomycorrhization in vitro. Mycorrhiza, 9:
65-68.
Burkert B. and Robson A, (1994). Zn uptake in subterranean clover (Trifolium
subterraneum) by three vesicular-arbuscular mycorrhizal fungi in a root free
sandy soil. Soil Biol. Biochem., 26: 1117–1124.
Cabanillas, E. and Barker, K. R. (1989). Impact of Paecilomyces lilacinus inoculum
density and application time on control of Meloidogyne incognita on Tomato.
J. Nematol, 21(1): 115-120.
Cabanillas, E., Barker, K. R. and Nelson, I. A. (1989). Growth of Isolates of
Paecilomyces lilacinus and their efficacy in biocontrol of Meloidogyne
incognita on Tomato. J. Nematol, 21 (2): 164-172.
Caporale, A. G., Sarkar, D., Datta, R., Punamiya, P., and Violante, A. (2014). Effect
of arbuscular mycorrhizal fungi (Glomus spp.) on growth and arsenic uptake
of vetiver grass (Chrysopogon zizanioides L.) from contaminated soil and
water systems. J. Soil Sci. Plant Nutria.,14(4): 955-972.
Cavagnaro, T. R., Langley, A. J., Jackson, L. E., Smukler, S. M. and Koch, G. W.
(2008). Growth, nutrition, and soil respiration of a mycorrhiza-defective
tomato mutant and its mycorrhizal wild-type progenitor. Functional Plant
Biol.,35(3): 228-235.
Chaubey, A. K., and Kumar, S. Bio-management of root knot nematode and root rot
disease by antagonistic fungi and rhizobacteria.
Chen, B., Xiao, X., Zhu, Y. G., Smith, F. A., Xie, Z. M., and Smith, S. E. (2007). The
arbuscular mycorrhizal fungus Glomus mosseae gives contradictory effects on
phosphorus and arsenic acquisition by Medicago sativa Linn. Sci. Total
Environ., 379(2): 226-234.
115
Colla G, Rouphael, Y. Cardarelli M, Tullio M, Rivera CM, and Rea E (2008).
Alleviation of salt stress by arbuscular mycorrhizal in zucchini plants grown at
low and high phosphorus concentration. Biol. Fertil. Soil., 44:501-509
Daniels, B. A. and Skipper. H. D. (1982). Mehods for the recovery and quantitative
srtimation of propagules from soil. In: N.C. Schenck, (ed), Methods and
Principles of Mycorrhizal Research. American Phytopathol. Soci., St Paul,
Minnesota, pp:244.
Das, G. P., Ramaswamy S. and Bari, M. A. (2000). Integrated crop management
practices for the control of the brinjal shoot and fruit borer in Bangladesh.
DAE-DANIDA Strengthening Plant Protection Services (SPPS) Project. Dept.
Of Agril. Extension. Khamarbari, Dhaka. 12pp
Davide, R.G. and Zorilla, R.A., (1987). Effects of a fungus, Paecilomyces lilacinus on
nodule formation and nematode infection on mungbean. Philippine
Phytopathol., (Philippines).
De La Peña, E., Echeverría, S. R., Van Der Putten, W. H., Freitas, H., and Moens, M.
(2006). Mechanism of control of root‐feeding nematodes by mycorrhizal fungi
in the dune grass Ammophila arenaria. New Phytologist. 169(4): 829-840.
De la Pena, E.1 and Moens (2007). Tritrophic interactions in coastal dunes:
Ammophila arenaria, root-lesion nematodes and plant mutualists. M. S. Afr. J.
Plant Soil. 24(4).
De, S., Sanyal, P.K., Sarker, A.K., Patel, N.K., Pal, S. and Mandal, S.C. (2009). Effect
of heavey metals and carbendazim on the in vitro growth of Purpureocillium
lilacinum (Thom.) Samson and Verticillium chamydosporium Goddard.
Proceedings of the Natinal Academy of Sciences India. Section B, Biol. Sci.,
(79): pp. 393-398.
116
Dhawan, S. C., Narayana, R. and Babu, N. P. (2004). Bio-management of root knot
nematode, Meloidogyne incognita in okra by Paecilomyces lilacinus. Ann. Pl.
Protec. Sci. 12(2): 356-359.
Dodd, J. C. (2000). The role of arbuscular mycorrhizal fungi in agro-and natural
ecosystems. Outlook on Agril., 29(1): 55-55.
Dong, Y., Zhu, Y. G., Smith, F. A., Wang, Y., and Chen, B. (2008). Arbuscular
mycorrhiza enhanced arsenic resistance of both white clover (Trifolium repens
Linn.) and ryegrass (Lolium perenne L.) plants in an arsenic-contaminated soil.
Env. Pollut, 155(1): 174-181.
Dos Santos, M.A., Ferraz, S. and Muchovej, J.J. (1992). Evaluation of 20 species of
fungi from Brazil for biocontrol of Meloidogyne incognita race 3.
Nematropica, 22(2): pp.183-192.
Eapen, S. J., Beena, B. and Ramana, K. V. (2005). Tropical soil microflora of spice-
based cropping systems as potential antagonists of root-knot nematodes. J.
Invertebrate Pathol.,88(3): 218-225.
Elahi, F. E., Mridha, M. A. U. and Aminuzzaman, F. M. (2010). Influence of AMF
inoculation on growth, nutrient uptake, arsenic toxicity and chlorophyll content
of eggplant grown in arsenic amended soil. Advan Nat. Appl. Sci, 4(2): 184-
192.
Elahi, F.E., Mridha, M.A.U. and Aminuzzaman, F.M. (2012). Role of AMF on Plant
growth, nutrient uptake, arsenic toxicity and chlorophyll content of chili
growth in arsenic amended soil. Bangladesh J. Agril. Res, 37(4): 635-644.
Elsen, A., Van der Veken, L., and De Waele, D. (2007). AMF-Induced bioprotection
against migratory plant-parasitic nematodes in banana. In International
Symposium on Recent Advances in Banana Crop Protection for Sustainable
Production and Improved Livelihoods 828 (pp. 91-100).
117
Esfahani, M. N. and Pour, B. A. (2006). The effects of Paeeilomyces lilacinus on the
pathogenesis of Meloidogyne javanica and tomato plant growth parameters.
Iran Agric. Res.,24 (2) and 25 (1): pp 67-76.
Farid, A.T.M., Roy, K.C., Hossain, K.M. and Sen, R. (2003). A study of arsenic
contaminated irrigation water and its carried over effect on vegetable. In:
Ahmed, M.F., Ali, M.A., Adeel, Z (eds) Fate of arsenic in the environments.
Proceedings of the international symposium on fate of arsenic in the
environments, ITN centre, BUET, Dhaka.
George, E. (2000). Nutrient uptake. In: Arbuscular Mycorrhizas: Physiology and
function. Kluwer Academic Press. p. 304-344.
Gerdemann, J.W. and Nicolson, T.H. (1963). Spores of mycorrizal endogone species
extracted from soil by wet-sieving and decanting. Trans. Br. Mydol. Soc.,46:
253-244.
Giovanetti, M. and Mosse, B. (1980). An evaluation of techniques for measuring
vesicular-arbuscular mycorrhizal infection in roots. New Phytologist. 84: 489-
500.
Giri, B., Kapoor, R. and Mukerji, K. G. (2005). Effect of the arbuscular mycorrhizae
Glomus fasciculatum and G. macrocarpum on the growth and nutrient content
of Cassia siamea in a semi-arid Indian wasteland soil. New Forests. 29(1): 63-
73.
Gomathi, C., Kumar, S., and Subramanian, S. (2006). Effective dose and methods of
delivery of Pasteuria penetrans against root knot nematode in brinjal. Ann. Pl.
Protec. Sci., 14(2): 452-455.
Gomes, M. P., Moreira Duarte, D., Silva Miranda, P. L., Carvalho Barreto, L.,
Matheus, M. T. and Garcia, Q. S. (2012). The effects of arsenic on the growth
and nutritional status of Anadenanthera peregrina, a Brazilian savanna tree. J.
Plant Nutri. Soil Sci.,175(3): 466-473.
118
Gomez, K.A. and Gomez, A.A. (1984). Statistical procedure for Agricultural
Research. 2nd ed./ Intl. Rice res. Inst., John Willy and Sons, New York,
chichester, Brisbane, Toranto, Singapore. p. 187-240.
Gonzalez‐Chavez, C., Harris, P. J., Dodd, J. and Meharg, A. A. (2002). Arbuscular
mycorrhizal fungi confer enhanced arsenate resistance on Holcus lanatus. New
Phytologist. 155(1): 163-171.
González-Chávez, M. D. C. A., del Pilar Ortega-Larrocea, M., Carrillo-Gonzalez, R.,
López-Meyer, M., Xoconostle-Cázares, B., Gomez, S. K. and Maldonado-
Mendoza, I. E. (2011). Arsenate induces the expression of fungal genes
involved in As transport in arbuscular mycorrhiza. Fungal biol., 115(12):
1197-1209.
González-Chávez, M. D. C. A., Miller, B., Maldonado-Mendoza, I. E., Scheckel, K.
and Carrillo-González, R. (2014). Localization and speciation of arsenic in
Glomus intraradices by synchrotron radiation spectroscopic analysis. Fungal
boil., 118(5): 444-452.
Gupta, ML and Janardhanan KK (1991). Mycorrhizal association of Glomus
aggregatum with palmarosa enhances growth and biomass. Plant Soil, 131:
261-263.
Gupta, V., Satyanarayana, T., and Garg, S. (2000). General aspects of mycorrhiza. In
Mycorrhizal Biology (pp. 27-44). Springer US.
Hajra, N., Shahina, F., and Firoza, K. (2013). Biocontrol of root-knot nematode by
arbuscular mycorrhizal fungi in Luffa cylindrica. Pakistan J. Nematol.,31(1):
77-84.
Hasan, N. (2004). Evaluation of a native strain of paecilomyces lilacinus against
Meloidogyne incognita in cowpea followed by lucerne. Annal. Plant Protec.
Sci, (India).
Herman, D. J., Firestone, M. K., Nuccio, E. and Hodge, A. (2012). Interactions
between an arbuscular mycorrhizal fungus and a soil microbial community
mediating litter decomposition. FEMS Microbiol. Ecol., 80(1): 236-247.
119
Hildebrandt, U., Regvar, M. and Bothe, H. (2007). Arbuscular mycorrhiza and heavy
metal tolerance. Phytochem., 68(1): p.139-146.
Hinata, K. (1986). Eggplant (Solanum melongena L.). in: Y.P.S. Bajaj (Ed).
Biotechnology in Agicultural and Forestry, J. Springer Verlag, Berlin,
Heidelberg. 2(1): 363-370.
Holbrook, B.A.D., Wilson, G.W.T and Figge, D.A.H. (1994). The influence of
Mycorrhizal symbiosis and fertilizer amendments on establishment of
vegetation in heavy metal mine spol. Environ. Pollut, 86:171-179.
Hunt, J. (1980). Determination of total sulphur in small amounts of plant material.
Analyst., 105(1246): 83-85.
Irfan, A. Z. I. Z., Ayoob, M., and JITE, P. K. (2011). Response of Solanum melongena
L. to inoculation with arbuscular mycorrhizal fungi under low and high
phosphate condition. Notulae Scientia Biologicae, 3(3): 70-74.
Islam, M. M. (2005). Management of phomopsis blight and fruit rot of eggplant
through chemicals and plant extracts. M.S. Thesis, Department of Plant
Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207, 60p.
Islam, S. (2006). The role of arbuscular mycorrhiza (AM) fungi on growth and
nutrient uptake of some legumes. M.S. Thesis. Dept. of Plant Path. Sher-e-
Bangla Agricultural University.
Jaime-Vega, M.C, Rodriguez-Romero, A.S. and Nunez, L.A.B. (2005). Effect of the
combined inoculation of arbuscular mycorrhizal fungi and plant growth
promoting rhizobacteria on papaya (Carica Papaya L.) infected with the root-
knot nematode Meloidogyne incognita. Fruits, 61: 1-7.
Jaizme-Vega, M. D. C., Rodríguez-Romero, A. S., and Barroso Núñez, L. A. (2006).
Effect of the combined inoculation of arbuscular mycorrhizal fungi and plant
growth-promoting rhizobacteria on papaya (Carica papaya L.) infected with
the root-knot nematode Meloidogyne incognita. Fruits, 61(03): 151-162.
120
Jatala, P. (1985). Biological control of Nematodes, In an Advanced Treatise on
Meloidogyne spp. Sasser J. and C. C Carter, (eds), North Carolina State
university Graphicd: Raleigh, NC, USA., pp: 303-308.
Jatala, P. (1986). Biological control of plant parasitic nematodes. Annual Rev.
Phytopatho, 24: 453-489.
Javaid, A. R. S. H. A. D., and Riaz, T. (2008). Mycorrhizal colonization in different
varieties of gladiolus and its relation with plant vegetative and reproductive
growth. Int. J. Agric. Biol., 10: 278-282.
Jefwa, J., Vanlauwe, B., Coyne, D., Van Asten, P., Gaidashova, S., Rurangwa, E., and
Elsen, A. (2008). Benefits and potential use of arbuscular mycorrhizal fungi
(AMF) in banana and plantain (Musa spp.) systems in Africa. In International
Conference on Banana and Plantain in Africa: Harnessing International
Partnerships to Increase Research Impact 879 (pp. 479-486).
Jones, J.B., Benjamin, B. and Mills, H.A. (1991). Plant analysis handbook, 1. Methods
of plant analysis and interpretation, Micro-macro Publ., Athens, GA, USA
213p.
Krishnappa K. R. and Rekha, D, I.J.S.N (2011). Interaction effect of arbuscular
mycorrhizal fungus, Glomus fasciculatum and root knot nematode
Meloidogyne incognita on biochemical parameters in tomato Shreenivasa,
2(3): 534-537
Kalele, D. N., Affokpon, A., Coosemans, J. and Kimenju, J. W. (2010). Suppression
of root-knot nematodes in tomato and Cucumber using biological control
agents. Afr. J. Hort. Sci, 3: 72-80.
Kapoor, R and Bhatnagar AK (2007). Attenuation of cadmium toxicity in mycorrhizal
celery (Apium graveolens L.). World J. Microbiol. Biotechnol. (in press).
121
Karagiannidis, N., Bletsos, F. and Stavropoulos, N. (2002). Effect of Verticillium wilt
(Verticillium dahliae Kleb.) and mycorrhiza (Glomus mosseae) on root
colonization, growth and nutrient uptake in tomato and eggplant seedlings.
Scientia Horticulturae, 94(1): 145-156.
Karimi, A. Khodaverdiloo, H., Sepehri, M., and Sadaghiani, M. R. (2011). Arbuscular
mycorrhizal fungi and heavy metal contaminated soils. African J. Microbiol
Res. 5(13): 1571-1576.
Kelkar, T. S. and Bhalerao, S. A. (2013). Beneficiary effect of arbuscular mycorrhiza
to Trigonella foenumgraceum in contaminated soil by heavy metal. Res. J.
Recent Sci, ISSN, 2277, 2502
Khalil M.S.E.H., Allam A.F.G., Barakat A.S.T. (2012). Nematicidal activity of some
bio-pesticide agents and microorganisms against root-knot nematode on
tomato plants under greenhouse conditions. J. Plant Prot. Res. 52 (1): 47–52.
Khan, A., Williams, K. L. and Nevalainen, H. K. M. (2006). Control of plant parasitic
nematodes by Paecilomyces lilacinus and Monacrosporium lysipagum in pot
trials. Biocontrol, 51(5): 643-658.
Khan, M.R. and Goswami, B.K., 2000. Effect of culture filtrates of Paecilomyces
lilacinus isolates on hatching of Meloidogyne incognita eggs. Annal. Plant
Protec. Sci., 8(1): pp.62-65.
Kiewick, S. and Sikora, R. A. (2006). Biological control of the root-knot nematode
Meloidogyne incognita by Purpureocillium lilacinum strain 251. Biological
control, 38: 179-187.
Kiewick, S., Neumann, S., Sikora, R. A. and Frey, J.E. (2011). Effect of Meloidogyne
incognita inoculum density and application rate of Purpureocillium lilacinum
strain 251 on biocontrol efficacy and colonization of egg masses analyzed by
real-time quantitative PCR. Phytopathol,101: 105-112.
122
Kiewnick, S. and Sikora R. A. (2004). Optimizing the efficacy of Paecilomyces
lilacinus (strain 251) for the control of root-knot nematodes. Commun. Agric.
Appl. Biol. Sc, 69 (3): 373-380.
Kiewnick, S. and Sikora, R. A. (2006 a). Biological control of the root-knot nematode
Meloidogyne incognita by Paecilomyces lilacinus strain 251. Biol. Control,
38: 179-187.
Kiewnick, S. and Sikora, R. A. (2006 b). Evaluation of Paecilomyces lilacinus
strain251 for the biological control of the northern root-knot nematode
Meloidogyne hapla Chitwood. J. Nematol.,8(1): 69 – 78.
Kiewnick, S., Mendoza, A. and Sikora, R. A. (2004). Efficacy of Paecilomyces
lilacinus (strain 251) for biological control of the burrowing nematode
Radopholus similis. J. Nematol, 36: 326-327.
Kiewnick, S., Neumann, S., Sikora, R. A. and Frey, J. E. (2011). Effect of
Meloidogyne incognita inoculum density and application rate of Paecilomyces
lilacinus strain 251 on biocontrol efficacy and colonization of egg masses
analyzed by real-time quantitative PCR. J. Phytopathol.,101 (1): 105-112.
Kim, D. Y., Lee, Y. J., Goo, N. I., Jung, J., and Kim, J. G. (2006, July). Effects of
arbuscular mycorrhizal fungi inoculation on arsenic and phosphorus uptake by
Trifolium repensin and Oenothera odorata Jacq. in Arsenic Contaminated Soil.
In The 18th World Congress of Soil Science.
Koske, R.E. and Gemma, J.H, (1989). A modified procedure for staining root to detect
VA mycorrhizas. Mycol. Res., 92: 486-505.
Leung, H. M., Ye, Z. H., and Wong, M. H. (2006). Interactions of mycorrhizal fungi
with Pteris vittata (Ashyperaccumulator) in As-contaminated soils. Env.
Pollut, 139(1): 1-8.
Li, T., Lin, G., Zhang, X., Chen, Y., Zhang, S. and Chen, B. (2014). Relative
importance of an arbuscular mycorrhizal fungus (Rhizophagus intraradices)
and root hairs in plant drought tolerance. Mycorrhiza, 24(8): 595-602.
123
Liu, X.Z. and Li, S.D. (2004). Fungal secondary metabolites in biological control of
crop pests in Handbook of Industrial Mycology, ed. Z.Q. An, New York:
marcel Dekker Inc, pp. 423-747.
Liu, Y., Zhu, Y. G., Chen, B. D., Christie, P. and Li, X. L. (2005). Influence of the
arbuscular mycorrhizal fungus Glomus mosseae on uptake of arsenate by the
As hyperaccumulator fern Pteris vittata L. Mycorrhiza. 15(3): 187-192.
Liu, Y., Zhu, Y.G., Chen, B.D., Christie, P. and Li, X.L., 2005. Yield and arsenate
uptake of arbuscular mycorrhizal tomato colonized by Glomus mosseae
BEG167 in As spiked soil under glasshouse conditions. Env. Int., 31(6): 867-
873.
Lopez-Llorca, L. V., J. G. Maciá-Vicente, and H-B. Jansson (2008). "Mode of action
and interactions of nematophagous fungi." Integrated management and
biocontrol of vegetable and grain crops nematodes. Springer Netherlands. 20.
51-76.
Manandhar Shrinkhala (2011). “Study on the bioprotective effect of endomycorrhizae
against M. graminicola in rice”. Lab. of Tropical Crop Improvement, Dept. of
Biosys., Faculty of Bioscience Engineering, Catholic University of Leuven,
3001 Leuven, Belgium.
Marro, N., Lax, P., Cabello, M., Doucet, M. E. and Becerra, A. G. (2014). Use of the
arbuscular mycorrhizal fungus Glomus intraradices as biological control agent
of the nematode Nacobbus aberrans parasitizing tomato. Brazilian Archives of
Biol. Tech., 57(5): 668-674.
Martin, S. B., Mueller, J. D., Saunders, J. A. and Jones, W. I. (1994). A survey of
South Carolina cotton fields for plant parasitic nematodes. Pl. Dis.,78: 717719.
Masadeh, B., Von Alten, H., Grunewaldt-Stoecker, G. and Sikora, R. A. (2004).
Biocontrol of root-knot nematodes using the arbuscular mycorrhizal fungus
Glomus intraradices and the antagonist Trichoderma viride in two tomato
cultivars differing in their suitability as hosts for the nematodes. J. Plant
Diseases Protec., 322-333.
124
Masri, B.M. (1997). Mycorrhizal inoculation for growth enhancement for growth
enhancement and improvement of the water relations in mungosteen (Garcinia
mangostana L.) seedlings. Ph.D. Thesis. University Putra, Malaysia, Serdong,
Malaysia.
Mittal, N., Saxena, G. and Mukerli, K. G. (1995). Integrated control of root-knot
disease in three crop plants using chitin and Paecilomyces lilacinus. Crop
Prot.14 (8): 647-651.
Mridha, M. A. H., Sultana, A., Sultana, N., Xu, H. L. and Umemura, H. (1999).
Biodiversity of VA mycorrhizal fungi of some vegetable crops in Bangladesh.
Proc. International Symposium on World Food Security and Crop Production
Technologies for Tomorrow, October 8-9. Kyoto, Japan 330-331.
Mridha, M. A. U., and Xu, H. L. (2001). Nature farming with vesicular-arbuscular
mycorrhizae in Bangladesh. J. Crop Prod, 3(1): 303-312.
Murphy, J. A. M. E. S. and Riley, J. P. (1962). A modified single solution method for
the determination of phosphate in natural waters. Analytica Chimica Acta. 27:
31-36.
Nisha, M. C and Rajeshkumar S. (2010). Effect of Arbuscular Mycorrhizal Fungi on
Growth and Nutrition of Wedilia chinensis (Osbeck) Merril. Indian J. Sci.
Technol., 3(6): 676–678.
Nogueira, M. A. and Cardoso, E. J. B. N. (2006). Plant growth and phosphorus uptake
in mycorrhizal rangpur lime seedlings under different levels of phosphorus.
Pesquisa Agropecuária Brasileira, 41(1): 93-99.
Noling, J. W. and Becker, J. O. (1994). The challenge of research and extension to
define and implement alternatives to ethylbromide. J. Nematol., 26: 573-586.
Oclarit E. L. Cumagun C.J.R. (2009). Evaluation of the efficacy of Paecilomyces
lilacinus as biological control agent of Meloidogyne incognita attacking
tomato. J. Plant Prot. Res. 49 (4): 337–340.
125
Oduor-owino, P. and Waudo, S. W. (1996). Effects of five fungal isolates on hatching
and parasitism of root-knot nematode eggs, juveniles and females. Nematol.
Medit, 24: 189-194.
Oduor-Owino, P. (2003). Integrated management of root-knot nematodes using
agrochemicals, organic matter and the antagonistic fungus, Paecilomyces
lilacinus in natural field soil. Nematol. Medit, 31: 121-123.
Orłowska, E., Godzik, B, and Turnau, K. (2012). Effect of different arbuscular
mycorrhizal fungal isolates on growth and arsenic accumulation in Plantago
lanceolata L. Env. Pollut. 168: 121-130.
Orr, C. C. and Robison, A. F. (1984). Assessment of cotton losses in western Texas
caused by Meloidogyne incognita. Pl. Dis. 68:284-292.
Ortas, I. (2010). Effect of mycorrhiza application on plant growth and nutrient uptake
in cucumber production under field conditions. Spanish J. Agril. Res.,8(S1):
116-122.
Pandey, R. C., and Dwivedi, B. K. (2001). Study on the effect of different biocontrol
agent against root knot disease of brinjal. Current Nematol, 12(1,2): 73-74.
Park, J.O., Hargreaves, J.R., McConville, E.J., Stirling, G.R., Ghisalberti, E.L.,
Sivasithamparan, K. (2004). Production of leucinostatis and nematicidal
activity of Australian isolates of Paecilomyces lilacinus (Thom) Samson. Lett.
Appl. Microbiol, 38 (3): 271–276.
Priyadharsini, P. and Muthukumar, T. (2015). Insight into the Role of Arbuscular
Mycorrhizal Fungi in Sustainable Agriculture. In Environmental Sustainability
(pp. 3-37). Springer India.
Rajan, S. K, Reddy, B. J. D. and Bagyaraj, D. J. (2000). Screening of Arbuscular Fungi
for Their Symbiotic Efficiency with Tectona grandis. Forest Ecol. Manage.,
126: 91–95
Rao, M. S., and Pavartha Reddy, P. (1998). Control of Meloidogyne incognita on
eggplant using Glomus mosseae integrated with Paecilomyces lilacinus and
neem cake [Solanum melongena L.-India]. Nematologia Mediterranea (Italy).
126
Rashid, M. M. (2000). A Guidebook of Plant Pathology. Dept. of Plant Pathology.
HSTU. Dinajpur. p:58
Requena, N., Perez-Soils, E., Azocon-Aguilar, C., Jeggries, P. and Barea, J.M. (2001).
Management of indigenous plant –microbe symbiosis aids restoration of
deserified ecosystems. Apl. Environ. Microbiol. 67: 495-498
Ronsheim, Margaret L. (2012). "The effect of mycorrhizae on plant growth and
reproduction varies with soil phosphorus and developmental stage." The
American Midland Naturalist. 167.1: 28-39.
Safir, G.R. (1994). Involvement of cropping systems, plant produced compounds and
inoculums production in the functioning of VAM fungi, in: Pfleger, F.L.,
Linderman R. G. (Eds), Mycorrhizae and plant health, APS press, Minnesota,
USA. p. 239-259.
Saha, N.K. (2008). Mycorrhizal status on crops grown in arsenic affected areas of
sonargaon district and effect of mycorrhiza on growth of some crops in arsenic
amended soil. M. S. Thesis, Dept. of Plant Path. Sher-e-Bangla Agricultural
University, Bangladesh.
Sankaranarayanan, C., and Sundarababu, R. (2009). Reciprocal influence of
arbuscular mycorrhizal fungus and root knot nematode and interaction effects
on blackgram. Nematologia Mediterranea. 37(2): 197-202.
Scannerini, S., and Bonfante-Fasolo, P. (1983). Comparative ultrastructural analysis
of mycorrhizal associations. Canadian J. Bot., 61(3): 917-943.
Schwarzott, D. Walker, C., and Schüßler, A. (2001). Glomus, the largest genus of the
arbuscular mycorrhizal fungi (Glomales), is nonmonophyletic. Mol. Phylogen.
Evol., 21(2): 190-197.
Sharma W. Trived P.C. (1997). Concomitant effect of Paecilomyces lilacinus and
vesicular arbuscular mycorrhizal fungi on root-knot nematode infested okra.
Ann. Plant Prot. Sci, 5 (1): 70–84.
127
Sharma, S. Parkash, V. and Aggarwal, A. (2008). Glomales I: A monograph of
Glomus spp. (Glomaceae) in the sunflower rhizosphere of Haryana, India.
HELIA, 31(49): 13-18.
Siddiqui, I. A., Qureshi, S. A., Sultana, V., Ehteshamul-Haque, S., and Ghaffar, A.
(2000). Biological control of root rot-root knot disease complex of tomato.
Plant and Soil, 227(1-2): 163-169.
Siddiqui, Z. A. and Akhtar, M. S. (2007). Biocontrol of a chickpea root-rot disease
complex with phosphate-solubilizing microorganisms. J. Plant Pathol, 67-77.
Siddiqui, Z. A. and Akhtar, M. S. (2008). Effects of fertilizers, AM fungus and plant
growth promoting rhizobacterium on the growth of tomato and on the
reproduction of root-knot nematode Meloidogyne incognita. J. Plant Interact,
3(4): 263-271.
Singh, P. K. Singh, M., Agnihotri, V. K., and Vyas, D. (2013). Arbuscular mycorrhizal
fungi: biocontrol against Fusarium wilt of chickpea. Int. J. Sci. Res, 3: 1-5.
Singh, Satyandra, and Nita Mathur (2010). "Biological control of root-knot nematode,
Meloidogyne incognita infesting tomato." Biocontrol Sci. Tech, 20.8: 865-874.
Smith, A. H., Lingas, E.O. and Rahman, M, (2000). Contamination by drinking
waterby arsenic in Bangladesh: a public health emergency. Bulletin of the
world health organization 78(9).
Smith, S. E., and Read, D. J. (2010). Mycorrhizal symbiosis. Academic press.
Smith, S. E., and Smith, F. A. (2012). Fresh perspectives on the roles of arbuscular
mycorrhizal fungi in plant nutrition and growth. Mycologia. 104(1): 1-13.
Smith, S. E., Christophersen, H. M. Pope, S., and Smith, F. A. (2010). Arsenic uptake
and toxicity in plants: integrating mycorrhizal influences. Plant and Soil,
327(1-2): 1-21.
Smith, S. E., Jakobsen, I., Grønlund, M., and Smith, F. A. (2011). Roles of arbuscular
mycorrhizas in plant phosphorus nutrition: interactions between pathways of
phosphorus uptake in arbuscular mycorrhizal roots have important implications
128
for understanding and manipulating plant phosphorus acquisition. Plant
Physiol., 156(3): 1050-1057.
Subarshan, C. and Chakraborty, S. (2001). Integrated management of root knot
nematode in eggplant. Indian J. Nemat., 31: 80-83.
Sun, M, H, M Gao, Li., Shi, Y.X., Li, B.J. and Liu, X.Z. (2006). Fungi and
actinomycetes associated with Meloidogyne spp. eggs and females in china and
their biocontrol potential. J. Invertebrate Pathol., 93: 22-28.
Syvertsen, J.P. and Graham, J.H. (1999). Phosphorus supply and arbuscular
mycorrhizas increase growth and net gas exchange responses of two citrus spp.
Grown at elevated (CO2). Plant and Soil. 208: 209-219.
Talukdar, M. J. (1974). Plant diseases in Bangladesh. J. Agril. Res, 1(1): 71.
Tanwar, A., Aggarwal, A., Kadian, N. and Gupta, A. (2013). Arbuscular mycorrhizal
inoculation and super phosphate application influence plant growth and yield
of Capsicum annuum. J. Soil Sci. Plant Nutri, 13(1): 55-66.
Trotta, A., Falaschi, P., Cornara, L., Minganti, V., Fusconi, A., Drava, G., and Berta,
G. (2006). Arbuscular mycorrhizae increase the arsenic translocation factor in
the As hyperaccumulating fern Pteris vittata L. Chemosphere, 65(1): 74-81.
Udo, I. A. Uguru, M. I. and Ogbuji, R. O. (2013). Pathogenicity of Meloidogyne
incognita Race 1 on tomato as influenced by different arbuscular mycorrhizal
fungi and bioformulated Paecilomyces Lilacinus in a dysteric cambisol soil. J.
Plant Protec. Res, 53(1): 71-78.
Ultra Jr, V. U. Tanaka, S., Sakurai, K., and Iwasaki, K. (2007). Effects of arbuscular
mycorrhiza and phosphorus application on arsenic toxicity in sunflower
(Helianthus annuus L.) and on the transformation of arsenic in the rhizosphere.
Plant and Soil 290(1-2): 29-41.
Usman, A. and M. A. Siddiqui (2012). Effect of some fungal strains for the
management of root-knot nematode (Meloidogyne incognita) on eggplant
(Solanum melongena). J. Agril. Tech., 8(1): 213-218.
129
van der Heijden, M., Rinaudo, V., Verbruggen, E., Scherrer, C., Bàrberi, P., and
Giovannetti, M. (2008). The significance of mycorrhizal fungi for crop
productivity and ecosystem sustainability in organic farming systems.
Vos, C. Claerhout, S., Mkandawire, R., Panis, B., De Waele, D. and Elsen, A. (2012).
Arbuscular mycorrhizal fungi reduce root-knot nematode penetration through
altered root exudation of their host. Plant and Soil, 354(1-2): 335-345.
Walia, R.K., Nandal, S.N. and Bhatti, D.S., (1999). Nematicidal efficacy of plant
leaves and Paecilomyces lilacinus, alone or in combination, in controlling
Meloidogvne incognita on okra and tomato. Nematologia Mediterranea, 27:
p.3-8.
Walker, H.L. and Connick, W.L. Jr. (1983). Sodium alginate for production and
formulation of mycoherbicides. Weed Sci, 31: 333-338.
Whitehead, A. D. and Hemming, A. K. (1965). Comparison of quantitative method of
extracting small vermiform nematodes from soil. Annal. Appl. Biol, 55: 25-38.
Williamson, V. M. and Hussey, R. S. (1996). Nematode pathogenesis and resistance
in plants. J. Plant Cell, 8: 1735-1745.
Xia, Y. S., Chen, B. D., christie, P., Wang, Y. S. and Li, X. L. (2007). Arsenic uptake
by arbuscular mycorrhizal maize (Zea mays L.) grown in an arsenic-
contaminated soil with added phosphorus. J. Env. Sci, 19(10): 1245-1251.
Yang, H., Dai, Y., Wang, X., Zhang, Q., Zhu, L. and Bian, X. (2014). Meta-analysis
of interactions between arbuscular mycorrhizal fungi and biotic stressors of
plants. Sci. World J.
Zhang, X., Ren, B. H., Wu, S. L., Sun, Y. Q., Lin, G. and Chen, B. D. (2015).
Arbuscular mycorrhizal symbiosis influences arsenic accumulation and
speciation in Medicago truncatula L. in arsenic-contaminated soil.
Chemosphere, 119: 224-230.