session 5.4 arbuscular mycorrhizal assoc and growth response of faidherbia
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Arbuscular mycorrhizal association and growth response of Faidherbida albida (Del.) A. Chev. as influenced by land use type, in the Northern Ethiopia
By: Mengsteab Hailemariam
February 2014
1. Introduction1. Introduction
1.1. Background and justification
Faidherbida albida:Leguminous agroforestry tree, used in arid and semiarid zones of Africa for soil conservation and soil fertility improvements.
Establishment and growth in dryland areas is very slow due to hostile environmental conditions.
plants possess against stress, grow in association with number of soil micro-organisms that can alleviate the stress symptoms.
AM are common underground symbiosis in revegetation by contributing to nutrient cycling processes
Cont’d…
before considering inoculation, a site's native inoculum potential should be evaluated Relationship between propagule abundance and plant
growth response is almost certainly not linear.
important to include plant response to different soil inoculum sources.
Cont’d…
The objectives of the study were: To determine spore abundance of AM in the soils
of F. albida trees grown in different LUs;
To estimate the extent of AM colonization of root of F. albida trees grown in different LUs, and
To investigate the effect of inoculation on the growth performance of F. albida seedlings;
2. Materials and methods2. Materials and methods
GH experiment was conducted in MU (130 290 N and 390 28 E altitude 2200 m.a.s.l.)
F. albida trees grown on different Lus, same agro-climatic condition and season were selected.
samples were collected for Spore analysisSpore analysis, AM colonization, , AM colonization, physico-chemical physico-chemical
analysisanalysis and and green house experimentgreen house experiment. .
Cont’d…
Soil properties OM, Total N, Ava. P, Exchangeable bases (Na, K, Ca
and Mg), and CEC, BD, pH and EC, and Soil texture
Spores: Extracted from 100g of air-dried sub-samples by wet
sieving and decanting method followed by flotation-centrifugation in 50% sucrose (Brundrret et al., 1996).
identified to genius level (Brundrett et al., 1996, and INVAM)
Cont’d…
AM colonization %estimated by the gridline intersect method
(Giovannetti and Mosse, 1980).
AM fungal inoculum preparation propagated on Sorghum bicolor plants 50 gm of fungal inoculums was added to each
experimental seedlings. controls were prepared without AM fungal propagules
Cont’d…
Seed treatment, planting and growing conditionsSeed treatment, planting and growing conditions
Seeds collected were surface sterilized and allowed to germinate on petridish and sown
Potted seedlings watered to field capacity.
Four treatments, arranged in CRD of five replication
Plants harvested after 12 weeks of growth and growth parameters were determined.
Cont’d…
Statistical analysisStatistical analysis
Data were subjected to ANOVA using SAS statistical software (SAS, version 9).
Relationship were evaluated by employing Pearson’s correlation coefficient.
Result and discussionResult and discussion
Soil properties and vegetation characteristicsSoil properties and vegetation characteristics
Significant difference in N, P, K, OC, Ca, Mg, Na, CEC and textural classes (P<0.05) showed in the three LUs.
Cul. and gra. Lands: weeds and variety of grasses, but area exlo. : grasses, herbaceous plants, shrubs species.
Significant (P<0.05) difference in DBH and Height of trees observed
Table 1: Mean plot characteristics of each LUT (Mean ± S.E of three replicates).
Soil properties
Unit
Land use type Cultivated land Grazing land
Area exclosure F P
pH (H2O, 1:2.5) 6.90 ± 0.09 6.71 ± 0.29 6.97a± 0.17 0.16 0.8522EC (ds/m) 0.15 ± 0.03 0.18 ± 0.05 0.11 ± 0.03 1.12 0.3857O.C (%) 1.003a ± 0.019 1.028 a± 0.061 0.8 b± 0.049 7.16 0.0257N (%) 0.074a ± 0.002 0.062a ± 0.06 0.035b ± 0.005 19.68 0.0023
Av.P (ppm) 13.07a ± 0.91 10.17 a± 1.46 1.46b ± 0.4925.68 0.0011
K (centmol(+)/kg 1.078a ± 0.057 0.778b ± 0.075 0.221c ± 0.03455.68 0.0001
Ca (centmol(+)/kg 2.67a ± 0.291 2.6 a± 0.208 1.4b ± 0.116 10.8 0.0103
Mg (centmol(+)/kg 2.58a ± 0.265 1.78b ± 0.104 1.18c ± 0.25710.09 0.0121
Na (centmol(+)/kg 0.507a ± 0.023 0.362ba ± 0.029 0.217b ± 0.00245.96 0.0002
CEC meq/100gm 6.20ba ± 0.378 7.733a ±0.698 4.80b ± 0.378 8.33 0.0185BD (g/cm3) 1.616 ± 0.039 1.471 ± 0.039 1.529 ± 0.037 3.64 0.0924
sand % 68.33b ± 0.67 86.33a ± 2.91 91.00a ± 1.1642.04 0.0003
silt % 19.00a ± 1.16 5.67b ± 1.76 3.0b ± 1.5538.15 0.0004
clay % 12.67a ± 0.67 8.0b ± 1.15 6.0b± 0.019.75 0.0023
Tex. Class Sandy loam Sandy Sandy DBH cm 49.4a±2.5 48.8a±6 16.4b±1.2 23.88 0.0014Height m 9.7a±0.9 7.9ba±0.4 6b±0.8 5.92 0.0381Crown diameter m 11.7b±0.7 14.6a±1.2 7.6c±0.5 15.75 0.0041
AM spore abundanceAM spore abundance
significant differences (F=24.01, P<0.0014) observed among samples collected from three LUs.
highest spores on soil samples from area exclo. and lowest from gra. land.
four genera recorded in all LUs. Glomus: abundant and frequent genus in all LUs
followed by Gigaspora Scutellospora and Acaulospora
AM root colonizationAM root colonization
Significant (F= 11.62, P= 0.0086) variation observed among tree root grown on different LUTs (Table 2).
Table 2: Spore abundance (100 gm-1 of dry soil) and AM root colonization of F. albida trees grown on different LUs. Mean ± S.E of three replications.
Land use type Spore abundance
F P AM root colonization
F P
Area exclosure 3041.3a ±148.34
24.01
0.0014 71.1a±1.7 11.62 0.0086
Grazing land 1364.0c ±205.56
66.5a±1.4
Cultivated land 2002.7b ±159.02
61.5b±1.1Means in the same column followed by same letter do not differ significantly at P<0.05
Growth parametersGrowth parameters Inoculated seedlings were colonized by AM fungal
structures (A, V, H) (Table 3).
None from control group were colonized.
the greater growth attained by the plants which were colonized by AM fungi.
significant (P<0.05) growth enhancements of seedlings inoculated with AMF was recorded.
AM colonization was not significantly correlated (r = 0.317, P = 0.376) with spores abundance.
Means in the same row followed by same letter do not differ significantly at P<0.05
Table 3: growth parameters of F. albida seedlings inoculated with AM fungal inoculums collected from the rhizosphere soils of F. albida trees grown on different LUs and AM un- inoculated seedlings. Mean ± S.E of five replicationsGrowth Parameters Unit Soils collected land use type
(AM-) Control
(AM+) Area exclosure
(AM+) Grazing land
(AM+) Cultivated land F value
P value
Height cm 44.0b ±4.16 96.67a±8.09 99.0a±8.96 67.0ba±6.56 13.32 0.0018
Shoot dry mass gm 2.06c±0.17 8.51a±0.39 8.21a±0.32 5.32b±0.49 67.57 <.0001
Root dry mass gm 1.09c±0.13 5.31a±0.79 5.19ba±0.48 2.73b±0.22 18.24 0.0006
Root: Shoot gg-1 0.529a±0.008 0.618a±0.063 0.629a±0.034 0.516a±0.008 2.64 0.1211
Root length cm 607.8d±100.5 3149.1a±189.9 2416.3b±309.8 1605.3c± 204.1 25.93 0.0001
Leaf number num 244.3c±20.4 725a±59.5 715.7a±59.29 609b±66.46 17.12 0.0007
Branch number num 2.33b± 0.88 5.00ba± 1.73 9.00a± 2.31 8.00ba±1.53 3.19 0.0840
AM
colonization % 0.0c±0.0 32.89a±1.60 30.25ba±2.14 25.23b±2.37 71.11 <.0001
Conclusion and recommendationConclusion and recommendation AM association can be influenced by LU systems, age of
trees, and environmental conditions
higher number of spores with low AM colonization observed in cultivated land compared with grazing lands, implies low level of infective AM populations.
Significant growth enhancement was recorded on AM inoculated seedlings.
Cont’d… higher growth performance observed on area exclo and
gra. Land soils emphasis the importance of prior native soil mycorrhizal
potentials for better plant growth improvement and environment protection.
investigating the potential of AM on growth performance of this tree spp. associated with different water levels and fertilizer application is needed, and
field experiment is needed to confirm the inoculation effects of these AM inocula, and
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