effect of gibberellic acid and potassium silicate on
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Pure Appl. Biol., 7(1): 8-19, March, 2018 http://dx.doi.org/10.19045/bspab.2018.70002
Published by Bolan Society for Pure and Applied Biology 8
Research Article
Effect of gibberellic acid and potassium
silicate on physiological growth of Okra
(Abelmoschus esculentus L.) under
salinity stress
Qasim Ayub*, Shah Masaud Khan, Ayub Khan, Ijaz Hussain, Zahoor
Ahmad and Muhammad Affan Khan Department of Agricultural Sciences, University Of Haripur, KP-Pakistan *Corresponding author’s email: qasimkhan.alizai@gmail.com Citation
Qasim Ayub, Shah Masaud Khan, Ayub Khan, Ijaz Hussain, Zahoor Ahmad and Muhammad Affan Khan. Effect of
gibberellic acid and potassium silicate on physiological growth of Okra (Abelmoschus esculentus L.) under salinity
stress. Pure and Applied Biology. Vol. 7, Issue 1, pp8-19. http://dx.doi.org/10.19045/bspab.2018.70002
Received: 23/09/2017 Revised: 22/12/2017 Accepted: 23/12/2017 Online First: 01/01/2018
Abstract The aim of this investigation was to improve salt tolerance abilities in okra (Abelmoschus
esculentus L.) by foliar application of potassium silicate and seed priming with GA3. A pot
experiment was conducted at Awan Nursery Farm, Haripur, to investigate whether seed priming
with GA3 and foliar application of potassium silicate could ameliorate the toxic effects of salinity
on okra growth. Two okra cultivars Sabz Pari and Mehak Pari were exposed to two levels of NaCl
(control and 50mM) according to the saturation percentage of soil. Seeds of okra were primed with
three levels of GA3 (50mg/L, 75mg/L and 100mg/L) before sowing. After 18 days of germination
okra plants were treated with three levels of potassium silicate (2mmol, 3mmol and 4mmol)
exogenously as foliar spray to protect the plants against salt stress. Data for different growth
parameters such as root length, shoot length, plant height, root and shoot fresh weight, root and
shoot dry weight were collected. Okra cultivar Sabz Pari showed maximum resistance towards
salinity as compared to Mehak Pari. Applications of GA3 decreased the harmful effects of salinity
and enhanced the overall growth of okra whereas silicon failed to impart any significant difference
on okra.
Keywords: Gibberellic Acid; Growth; Okra; Potassium silicate; Salinity
Introduction Okra (Abelmoschus esculentus L.) also
known as lady finger in English and bhindi in
Urdu, is a green flowering plant belong to
family Malvacae. It is grown for its edible
seed pods in tropical and sub-tropical
regions. Okra is annual or perennial
depending on the climatic conditions. It
grows up to 2m high, having leaves 10cm to
20cm in length. Diameter of okra flowers are
4 to 8, having white or yellow petals, with a
red or purple spot on each petal base. Fruit of
okra is a capsule shaped pod having length up
to 18 cm, each pod contain numerous white
edible seeds. Okra is cultivated for its fibrous
pods. It has high heat and drought tolerance
among most of the vegetables, and can also
give better yield in heavy soils and in soils
Ayub et al.
9
with low moisture content, but it have low
tolerance against chills and frosts. Okra is a
popular vegetable among both the consumers
and farmers because it is rich in vitamins and
minerals [1]. Greenish yellow okra oil is also
obtained from okra seeds, which can be used
as bio fuel [2].
Many abiotic stresses like high and low
temperatures, drought and salinity reduces
the growth and productivity of crops [3] but
among these, salt stress imparts a severe
reduction in plants growth and reproduction
[4]. According to some estimates about
831x106 hector lands is affected by salinity
[5] whereas one-half of total irrigated land
(which is about 2.5 x 108 hector) is severely
affected by salinity [6].
Elevated salt concentrations inside plant
tissues reduces the growth and development
by altering physiological processes, such as
change in ions balance, water status, mineral
nutrition, open and closing of stomata, and
rate of photosynthesis [7]. Most plants are
sensitive to salt having relatively low salt
tolerance or show clear reduction in growth
at lower salinity levels [8, 9]. Salt stress
causes osmotic and ionic stress which in turn
affects plant growth at both whole plant and
at cellular level [10]. Higher number of toxic
ions of salts in soil decreases soil water
potential and availability of water to plants
[11]. This shortage of available water under
saline conditions causes dehydration at
cellular level and eventually osmotic stress
occurs. Excess of toxic Sodium and chloride
ions hinders the uptake of useful ions such as
Potassium, Calcium and Manganese [12].
Numerous plant hormones are recognized for
their fruitful effects on those plants which are
exposed to salinity; among these hormones
Gibberellins (GA3) has attained the prime
attentions of scientists [13]. Gibberellic acid
activates the cells of seeds during
germination to generate mRNA molecules,
which contains the code for hydrolytic
enzymes [14]. GA3 enhances the stem
elongations [15], for example when dwarf
bean treated with GA3, turn them into a
climbing bean [16]. Gibberellins (GA3) play
an important part in different stages of plant
growth and development, such as
germination [16-20], stem enlargement and
flower development [21]. GA3 also increases
vegetative growth in plants such as leaf area,
leaf length and width [22].
Silicon is the second most widely found
element in the earth crust, whose
accumulation rate in plants is similar to those
other macro-elements nutrients like calcium,
magnesium and phosphorus [23]. The
beneficial effects of silicon vary in different
growing conditions, these effects are usually
most prominent when plants are exposed to a
verity of abiotic or biotic stresses [24]. It has
been reported by many scientists that silicon
reduces the harmful effects of various abiotic
stresses such as manganese, aluminum and
heavy metal toxicities, soil salinity, drought
stress, chilling and freezing injuries [25].
Moreover, it has been suggested that silicon
enhances the growth of plants and reduces the
toxic effects of salinity by reducing the
specific ion effect of salinity [26]. The effect
of silicon on plant growth depends upon
silicon doses and crop [27]. Among all
minerals silicon is only element whose
excessive amounts do not damage plants due
to its polymerization property and non
dissociation at physiological pH [24].
GA3 and silicon have been used on number of
crops and the main aim of this study in to find
out beneficial outcomes of GA3 and
potassium silicate (silicon) on okra when
grown under salt stress, and to investigate
suitable gibberellic acid and potassium
silicate rate for okra when subjected to
salinity stress.
Materials and methods
Current study was conducted at Awan
Nursery farm Haripur, during summer 2016.
Two okra verities were used namely Sabz
Pari and Mehak Pari. Both verities were
Pure Appl. Biol., 7(1): 8-19, March, 2018 http://dx.doi.org/10.19045/bspab.2018.70002
10
selected from local market. Pots of 18 inch
diameter were filled with dam silt. In order to
fulfill plants nutritional requirements
farmyard manure were added in each pot.
Eight seeds were planted in each pot, after 10
days of germination, plants were thinned to
five plants per pot. The experiment was laid
in Complete Randomized Design (CRD).
Each treatment was replicated three times.
Averages were calculated for recorded data
in each replication. These averages were then
subjected to statistical analysis for ANOVA
and LSD [28]. Data were analyzed by using
statistical software Statistix 8.1.
Seed treatment with GA3
The seeds of okra were treated with 50,
75,100 mg/L solution of GA3 before sowing.
Seed were kept in 50ml size beakers for 8
hours, each beaker was properly air tightened
by polyethen sheet.
Silicon levels and application
During this study three silicon level 2mM,
3mM and 4mM were used. Potassium silicate
was mixed in distillated water and was
applied to plants exogenously two days
before the salt application in order to lower
the harmful effect of salt and to prevent plants
from scorches and leaf burning.
Salinity levels
Two salinity levels i.e. control and 50mM
were used for the experiment. Plants were
subjected to salt 20 days after the
germination. In order to prevent plants from
osmotic stress due to salt, final concentration
of salinity i.e. 50mM was completed in two
steps. In first step 25mM salt was applied,
and remaining 25mM of salt was added two
days later.
Parameters
Shoot length (cm)
Measuring rod was used for measurement of
shoot length. One plant form each replication
is taken and the length of shoot is measured
from base to the tip of shoot.
Root length (cm)
The length of root was measured in
centimeter with the help of measuring rod.
One plant from each replication was uprooted
and the length of root was measured from
base to the tip of longest root.
Plant height (cm)
Total plant height was calculated by adding
the root length and shoot length of each plant.
Shoot fresh weight (gm)
The weight of shoots was measured by using
digital balance. The roots were detached from
the stem and the stem is cut into two or three
small pieces so that the weight of long stems
can easily be calculated.
Root fresh weight (gm)
The fresh weight of roots was measured by
using digital balance. The roots were washed
properly to remove any dust ore mud on
them. Then these washed roots were dried on
tissue paper to remove any extra water on
them.
Shoot dry weight (gm) The shoots were kept in oven for 24 hours at
a temperature of 60̊ C. After 24 hours the
dried shoots were weighted by using a digital
balance.
Root dry weight (gm)
To find the dry weight of shoots, shoots were
oven dried and were kept in oven for 24 hours
at 60̊ C. After 24 hours the shoots are
weighted for dry weight by using a digital
balance.
Results and discussions
Shoot Length (cm)
Statistically significant differences were
observed in salt, treatment and variety for
shoot length, whereas the interactions
salt*variety and treat*variety were
statistically significant (Table 1).
Maximum shoot length (38.92 cm) was
observed in control while minimum shoot
growth (37.21cm) was observed at 50mM
salinity (Table 2). The maximum shoot
length in non-saline soils may be due to fact
that these plants have osmotically adjusted
Ayub et al.
11
themselves in a way which helps in cell
elongation hence [29].
The okra cultivar Sabz Pari showed the
maximum shoot length (41.76cm) when
grown in non-saline conditions. Similarly the
minimum shoot length (36.09cm) was
observed in Mehak Pari when grown in
50mM salinity (Table 3); same results were
found by [30]. The decreased growth of shoot
because of salinity is due to low water
potential inside plants tissues which cause a
decrease in cell turgidity; this low cell turgor
reduced cell elongation and cell division [31].
At higher salinity closing of stomatal walls
occurred which limits carbon dioxide
absorption by the plant, as CO2 is main
energy source for plants and their growth
development depend upon amount of
absorbed CO2, thus a reduced stem growth
obtained [32].
The maximum shoot length (44.66cm) was
noted in Sabz Pari when treated with 4mMol
potassium silicate, whereas as minimum
shoot length (34.33cm) was observed in
Mehak Pari when treated with 3mM silicon
(Table 3). These results indicate that silicon
have imparted a significant increase in shoot
length of okra. Silicon is considered as
essential element for plants because silicon
deficient plants show many growth
abnormalities [33]. Plant root absorb silicon
in the form of Silicic acid [(Si (OH)4] [34].
This difference in shoot length among okra
cultivars may be due to availability of silicon
to plant, which mainly depend on soil pH,
presence of aluminum and iron oxide [35]
and plant species [24].
Table 1. Analysis of variance table of shoot length (SL), root length (RL), plant height (PH),
shoot fresh weight (SFW), root fresh weight (RFW), shoot dry weight (SDW), root dry weight
(RDW)
Source DF S L(cm) R L (cm) P H (cm) SFW (g) RFW (g) SDW (g) RDW (g)
Salt 2 61.714** 1.190NS 45.76** 0.093NS 0.17554** 0.0805NS 0.04030**
Treat 1 11.567* 1.361NS 16.07* 0.191* 0.01301** 0.1862* 0.00609**
Variety 6 260.762** 663.048** 1755.43** 154.714** 2.80869** 62.0576** 0.91354**
Salt*Treat 1 2.853NS 2.718* 6.07NS 0.082NS 0.00482* 0.0830NS 0.00112NS
Salt*Variety 6 96.429** 0.429NS 109.71** 0.347* 0.45762** 0.3219* 0.20800**
Treat*Variety 1 53.067** 3.687* 50.68** 0.146* 0.02657** 0.1529* 0.01016**
Salt*Treat*Variety 6 1.290NS 3.567* 1.96NS 0.081NS 0.02084** 0.0877NS 0.00714*
Error 6 4.993 1.161 4.18 0.052 0.00156 0.0518 0.00185
Total 54
Root length (cm)
Analysis of variance showed that interactions
salt*treatment, treatment*variety and
salt*treatment*variety were statistically
significant for P<0.005 (Table 1).
Maximum root length (15.81cm) was shown
by Sabz Pari while the Mehak Pari showed
the minimum root length (10.89cm) (Table
2). This difference in root length of both
tested cultivars of okra may be attributed to
genetic makeup of each cultivar and the
climatic conditions in which both cultivars
were grown [36].
The maximum root length (14.00cm) was
observed in plants which were grown in
control and non-saline soil, whereas the
minimum root length (12.00cm) observed in
plants grown under 50mM salinity and
treated by 2mMol solution of potassium
silicate (Table 3). These results suggest that
neither GA3 nor Si have imparted prominent
reduction to lower the toxic effect of salinity
but salinity reduces the root length of okra. A
decrease in root length with the increments in
salinity in present assessment confirmed the
results of previous studies [37- 30]. Roots of
plants are directly grown in growth media
Pure Appl. Biol., 7(1): 8-19, March, 2018 http://dx.doi.org/10.19045/bspab.2018.70002
12
containing toxic salt ions, which prevent the
long time root growth [40].
The maximum root length (16.50cm) was
observed in Sabz Pari when treated with
100mg/L of GA3, while minimum root length
(9.16cm) was observed in Mehak Pari when
treated with 100mg/L of GA3 (Table 3).
These outcomes are similar with those of [41]
who noted same increment on root length of
barley when treated with GA3. This increase
in root length of okra plants may be due to
proven fact that GA3 increases cell division
and elongation [42].
Table 2. Mean of salt, treatment and variety for shoot length (SL), root length (RL) plant
height (PH) and shoot fresh weight (SFW)
Salt SL (cm) RL (cm) PH (cm) SFW (g)
S1 38.929 A 13.119 A 51.810 A 4.7452 A
S2 37.214 B 12.881 A 50.333 A 4.6786 A
Treatment
T1 36.917 B 13.417 A 50.333 B 4.9667 A
T2 37.417 B 12.667 A 50.083 B 4.7917 AB
T3 37.833 B 12.917 A 50.750 B 4.6833 B
T4 37.833 B 12.833 A 50.667 B 4.6333 B
T5 38.000 B 12.667 A 50.667 B 4.6417 B
T6 38.500 AB 13.000 A 51.500 B 4.6333 B
T7 40.000 A 13.500 A 53.500 A 4.6333 B
Variety
V1 39.833 A 15.810 A 55.643 A 6.0690 A
V2 36.310 B 10.190 B 46.500 B 3.3548 B
Plant height (cm)
Results concerning interaction of salt*variety
and treatment*variety, were statistically
highly significant (P<0.001), whereas the
interaction salt*treatment and
salt*treatment*variety were non-significant
(P>0.005) (),
Sabz Pari showed the maximum plant height
(57.52cm) when grown under control,
similarly the minimum plant height
(46.09cm) was noted in Mehak Pari when
grown in 50mM salinity (Table 2). These
results are in accord with [29, 36] who also
reported that increasing salt level cause a
significant decrease in height of okra plants.
The prominent symptoms of soil salinity on
okra plants were stunted growth [43]. Those
okra plants which were grown under non
saline soils may have osmotically adjusted
themselves according to growing conditions
due to which plants have managed to attain
desirable cell enlargement hence showed
maximum plant height [30]. The decreased
plant height under saline soil can be
attributed to toxic effect of sodium and
chloride ions and lower water potential in
root zone [44].
The maximum plant height was noted in Sabz
Pari (66.32cm) when treated with 4mM
silicon solution, while the minimum plant
height was observed in Mehak Pari
(44.66cm) when treated with 3mM solution
of potassium silicate (Table 2). These results
are in accord with [45] who noted that at
increasing levels of silicon, the height of
wheat plants also increased.
Shoot fresh weight (g)
The interactions Salt*Variety and
Treat*Variety were significant for P<0.005
whereas the interactions salt*treatment and
salt*treatment*Variety were non-significant
(Table 1).
Ayub et al.
13
Table 3. Mean of interactions salt x treatment, salt x variety and treatment x variety for
shoot length (SL) root length (RL) plant height (PH) and shoot fresh weight (SFW)
Salt x Treatment SL (cm) RL (cm) PH (cm) SFW (g)
S1xT1 38.167 BCDE 14.000 A 52.16 ABCD 5.1833 A
S1xT2 38.167 BCDE 12.333 BCD 50.50BCDEF 4.8167 B
S1xT3 38.667ABCD 12.833ABCD 51.500 BCDE 4.7000 B
S1xT4 38.00ABCDE 12.167 CD 50.167 DEF 4.6167 B
S1xT5 39.500 ABC 13.333 ABC 51.500 BCDE 4.6333 B
S1xT6 39.667 AB 13.00ABCD 52.667 ABC 4.6500 B
S1xT7 40.333 A 13.833 A 54.167 A 4.6167 B
S2xT1 35.667 E 12.83ABCD 48.500 F 4.7500 B
S2xT2 36.667 DE 13.00ABCD 49.667 EF 4.7667 B
S2xT3 37.000 CDE 13.00ABCD 50.000 DEF 4.6667 B
S2xT4 37.667 BCDE 13.500 AB 51.167 BCDE 4.6500 B
S2xT5 36.500 DE 12.000 D 49.833 DEF 4.6500 B
S2xT6 37.333 BCDE 13.00ABCD 50.333 CDEF 4.6167 B
S2xT7 39.667 AB 13.16ABCD 52.833 AB 4.6500 B
Salt x Variety
S1xV1 41.762 A 15.762 A 57.524 A 6.0381 A
S1xV2 36.524 BC 10.000 B 46.905 C 3.4524 B
S2xV1 37.905 B 15.857 A 53.762 B 6.1000 A
S2xV2 36.095 C 10.381 B 46.095 C 3.2571 C
Treatment x Variety
T1XV1 36.333 EFG 15.667 A 52.000 E 6.1167 AB
T2xV1 37.167 DEF 15.500 A 52.667 E 6.2500 A
T3xV1 38.333 CDE 15.833 A 54.167 DE 6.1000 AB
T4xV1 39.000 CD 16.500 A 55.500 CD 6.1000 AB
T5xV1 40.667 BC 16.000 A 56.667 BC 6.0167 AB
T6xV1 42.667 AB 15.500 A 58.167 AB 5.9333 B
T7xV1 44.667 A 15.667 A 60.333 A 5.9667 B
T1xV2 37.500 DEF 11.167 BC 48.667 F 3.8167 C
T2xV2 37.667 DEF 9.833 DE 47.500 FG 3.3333 D
T3xV2 37.333 DEF 10.000 CDE 47.333 FG 3.2667 D
T4xV2 36.667 DEFG 9.167 E 45.833 GH 3.1667 D
T5xV2 35.333 FG 9.333 DE 44.833 H 3.2667 D
T6xV2 34.333 G 10.500 BCD 46.667 FGH 3.3333 D
T7xV2 35.333 FG 11.333 B 45.222 GH 3.3000 D
T1=Control T2=GA3 50mg/L, T3= GA3 75mg/L, and T4= GA3 100 mg/L, T5= Si 2mMol, T6=Si 3mMol,
T7=Si 4 mMol, S1= control, S2=50mM, V1=SABZ PARI V2=MEHAK PARI
Maximum shoot fresh weight was notes in
Sabz Pari (6.03 gm) when grown under
control, whereas the minimum shoot fresh
weight (3.25 gm) was seen in Mehak Pari
when subjected to 50mM salinity (Table 2).
These results are in accordance with [46] who
reported that saline medium have adversely
affected the shoot fresh weight of okra. Plants
grown under saline stress failed to set off the
dehydration avoidance mechanism which
made the root membranes resistant for toxic
ions of Na+ and Cl- and failed to keep
stomatal conductance up to desirable rate
[47], thus plants could not bear the high salt
stress and experienced the drop in growth of
fresh weight [30]. Soil salinity causes soil
Pure Appl. Biol., 7(1): 8-19, March, 2018 http://dx.doi.org/10.19045/bspab.2018.70002
14
water stress, which hinders the development
of the growing tissues as a result decrease in
shoot fresh weight occurs [7].
Sabz Pari showed highest shoot fresh weight
(6.25 gm) when treated with 50mg/L GA3
solution whereas the minimum shoot fresh
weight (3.16 gm) was noted in Mehak Pari
when treated with 100mg/L of GA3 (Table 2).
[48] have also reported an increase in shoot
fresh weight of okra plants when treated with
GA3. GA3 is usually related with cell
division, physiological growth of plants,
these hormones manages seed germination,
leaf expansion, stem enlargement and
flowering [49, 50].
Root fresh weight (g)
The maximum value of root fresh weight
(1.14 gm) was noted in those okra plants
which were treated with 50 mg/L GA3
solution and grown under control, while
minimum root fresh weight (0.91 gm) was
noted in plants grown under 50 mM salinity
and treated with 4 mM silicon (Table 4).
These results are in agreement with those of
[48] who noted similar increase in root fresh
weight of okra when treated with GA3. The
results of current study confirmed the
beneficial effect of GA3 treatment on Okra
plants, plants showed maximum root fresh
weight which were treated with GA3 as
compared to those plants which were treated
only with salt.
The maximum root fresh weight (1.21gm)
was show by Sabz Pari under control, while
minimum root fresh weight (0.70gm) was
noted in Mehak Pari when grown in 50 mM
salt level (Table 4). Salinity negatively
affected the root dry weight of both cultivars.
Similar reduction in root fresh weights of
Cabbage, Sugar beet, Paniculate amaranth
and Pak-choi due to salinity was also noted
by [51- 53]. Roots have less salt tolerance
than the shoots, because roots were grown
directly in saline soil having high
concentrations of Na+ ion in root zone, which
imparts osmotic effects and reduces growth
and development of roots [54-56].
Maximum root fresh weight (1.21gm) was
noted in Sabz Pari when treated with 75mg/L
GA3 and minimum root fresh weight (0.74
gm) was observed in Mehak Pari when
treated with 4mM silicon (Table 4). [48]
observed similar increase in the root fresh
weight of okra and [56] in soya beans when
treated with GA3
Shoot dry weight (g)
Sabz Pari showed maximum shoot dry
weight (3.10g) under control, whereas Mehak
Pari showed minimum shoot dry weight
(1.25g) when grown under 50mM salinity
(Table 4). These findings were in agreement
with [29, 46, 58] who noted that salinity
imparted significant reduction in shoot dry
weight of okra. It was evident that at 50mM
salinity, decrease in dry shoot weight of
plants was more as compared to that of
control. Plants which were treated with
higher salinity level (50mM) cannot avoid
dehydration, have high sodium and chloride
ion toxicity inside roots, and experienced low
stomatal conductance, all these factors
contributed towards reduction in dry weight
of shoots [30, 47].
The maximum shoot dry weight (3.25g) was
noted in Sabz Pari when treated with 50mg/L
GA3, whereas the minimum shoot dry weight
(1.16g) was noted in Mehak Pari when
treated with 100mg/L GA3 (Table 4). [48]
also confirmed these results who reported
that GA3 enhances the shoot dry weight of
okra; while working on tomato plants an
increase in shoot dry weight was noted when
treated with GA3 [59, 60].
Root dry weight (g)
Sabz Pari showed maximum root dry weight
(0.91g) under control, whereas Mehak Pari
showed minimum root dry weight (0.60g)
when grown under 50mM salinity (Table 4).
These findings were similar to [30, 61].
Reason for this reduced root dry weight under
salinity stress could be, insufficient
Ayub et al.
15
photosynthesis, fewer stomatal conductance,
and therefore inadequate carbon dioxide
uptake [62, 63] which in turn produced less
dry root mass. Salinity also decreases cell
division and cell expansion [64]. The
reduction in root dry weight may be because
of reduced root length which is commonly
seen in plants grown under salt stress [55,
56].
Table 4. Mean of interaction salt x treatment x variety for root fresh weight (RFW), shoot
dry weight (SDW) and root dry weight (RDW)
SALT x TREATMENT x VARIETY RFW(g) SDW (g) RDW (g)
S1xT1xV1 1.0700 F 3.1667 AB 0.7700 FGH
S1xT2xV1 1.1533 CDE 3.3000 A 0.8533 CDE
S1xT3xV1 1.2167 ABC 3.1000 ABC 0.9167 ABC
S1xT4xV1 1.1867 ABCD 3.0667 ABC 0.8867 ABCD
S1xT5xV1 1.1533 CDE 3.0000 ABC 0.8533 CDE
S1xT6xV1 1.1733 BCDE 2.8667 BC 0.8733 BCDE
S1xT7xV1 1.1800 BCD 2.7667 C 0.8800 ABCDE
S1xT1xV2 1.1133 EF 2.2000 D 0.8133 EFG
S1xT2xV2 1.1367 DE 1.2667 E 0.8367 DEF
S1xT3xV2 0.8533 HI 1.3000 E 0.7533 GHI
S1xT4xV2 0.8133 IJ 1.1667 E 0.6800 JKL
S1xT5xV2 0.9267 G 1.2667 E 0.7233 HIJ
S1xT6xV2 0.9033 GH 1.4667 E 0.7700 FGH
S1xT7xV2 0.8600 HI 1.4333 E 0.6933 IJK
S2xT1xV1 1.2233 AB 3.0667 ABC 0.9200 ABC
S2xT2xV1 1.2133 ABC 3.2000 AB 0.9133 ABC
S2xT3xV1 1.2133 ABC 3.1000 ABC 0.9133 ABC
S2xT4xV1 1.1900 ABCD 3.1333 ABC 0.8900 ABCD
S2xT5xV1 1.2267 AB 3.0333 ABC 0.9267 AB
S2xT6xV1 1.2467 A 3.0000 ABC 0.9467 A
S2xT7xV1 1.2233 AB 3.1667 AB 0.9133 ABC
S2xT1xV2 0.7200 KLM 1.4333 E 0.6200 LMN
S2xT2xV2 0.7633 JK 1.3333 E 0.6633 JKLM
S2xT3xV2 0.7467 KL 1.1667 E 0.6467 KLMN
S2xT4xV2 0.7367 KL 1.2667 E 0.6367 KLMN
S2xT5xV2 0.6867 LM 1.2333 E 0.5867 NO
S2xT6xV2 0.6600 MN 1.1333 E 0.5933 MN
S2xT7xV2 0.6200 N 1.2333 E 0.5200 O
T1=Control T2=GA3 50mg/L, T3= GA3 75mg/L, and T4= GA3 100 mg/L, T5= Si 2mMol, T6=Si 3mMol,
T7=Si 4mMol, S1= control, S2=50mM, V1=SABZ PARI V2=MEHAK PARI
It was observed that Sabz Pari showed
maximum root dry weight (0.91g) when
treated with 50mg/L GA3, whereas the
minimum root dry weight (0.60g) was
showed by Mehak Pari treated with 4mM
silicon (Table 4). The increase in root dry
weight could be attributed to the fact that GA3
enhance cell growth, and cell division [65],
due to this increased number of cells okra
plants treated with GA3 showed maximum
root dry weight. The promoting effects of
GA3 increased the multiplication of ribose
and polyribosome, which caused an
increment towards biomass of aerial plant
parts, improved activity of enzymes, may
also result in biomass gathering in plants as
they grow. GA3 increase membrane
permeability which in turn facilitated
Pure Appl. Biol., 7(1): 8-19, March, 2018 http://dx.doi.org/10.19045/bspab.2018.70002
16
assimilation and consumption of mineral
nutrients [66]. This would have contributed
towards enhancing the capacity of the treated
plants for increased biomass production.
Conclusions and recommendations
It is obvious that salt stress have imparted
destructive effects on the growth and
development of okra. However, the response
to salinity differs greatly among both okra
cultivars; Sabz Pari showed maximum
tolerance against salt stress as compared to
Mehak Pari. The use of exogenous GA3 and
Potassium Silicate under salt stress condition
has been found to be very much effective to
alleviate salt induced damages and increased
the root length, shoot length, plant height,
root and shoot fresh weight, root and shoot
dry weight of tested okra cultivars.
Authors’ contributions Conceived and designed the experiments:
SM Khan, Performed the experiments: Q
Ayub, Analyzed the data: A Khan & MA
Khan, Contributed reagents/ materials/
analysis tools: I Hussain & Z Ahmad, Wrote
the paper: Q Ayub.
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