Introduction
Cotton is
cultivated as an annual crop and shares a great part in the world’s economy. Pakistan is the fourth cotton producing country in the
world; however, it stands at 10th position in terms of yield (Shuli et al.
2018). It is the backbone of Pakistan economy; its contribution in GDP
(Gross Domestic Product) is 0.8% and 4.5% in agriculture value addition (Economic Survey of Pakistan 2018–2019).
Cotton grows well in areas having 50 mm rainfall
annually with heavy showers at the time of boll formation (Nazir
2007). Maximum yield in cotton depends on unfavorable temperature conducive
for disease development and minimum insect pest attacks throughout the growing
season. Among all factors responsible for low yield, plant parasitic nematodes
such as Meloidogyne incognita and root rot fungi such as Rhizoctonia bataticola
are considered key pests producing galls and rotting on cotton roots (Agrios 2005; Anwar and Mckerny
2007). Many studies on interactions between fungi and endoparasitic
nematodes have been well documented (Powell 1971; Tu
and Cheng 1971; Kellam and Schenck
1980; Atilano et
al. 1981; Edin et al. 2019). Meloidogyne spp. not only causes malfunctioning of roots but also
facilitates penetration of fungal pathogens (Singh 1975).
Pakistan
lies between 24o 00' N and 79o
00' E, with subtropical climate and
is vulnerable to climate change. The favorable conditions for the optimal
growth of Meloidogyne
spp. are short winter, high temperature, sandy
loam soil and hot climate (Maqbool 1987). Srinivas et al. (2017) tested the effect of seven
temperature regimes on growth of R. bataticola and observed maximum mycelial
growth at 35oC followed by 30oC and 25oC.
Anwar and Mckerny (2007) reported that environmental
changes particularly favor root rot fungi and root-knot nematodes, thus, their
interaction leads to the crop failure.
M. incognita and R. bataticola are more prevailing pathogens in cotton
growing areas of Sindh and Punjab (provinces of Pakistan) and responsible for
high yield losses in cotton (Iqbal et al. 2012; Khan et al. 2017). The modifications
induced by root-knot nematodes, either local or systemic, increase the
susceptibility of host plants to other soil-borne fungi (Siddique
et al. 2004). Cotton varieties
cultivated in Pakistan are unable to reach their genetic potential because of
biotic (root rot fungi; root knot nematodes) and abiotic (temperature) factors.
The data presented in literature indicated that there are few resistant
varieties of cotton against root-knot nematodes (Cook 1997; Robinson 1997;
Kirkpatrick 1989; Anwar and Mckenry 2007; Khan et al. 2017). Using resistant varieties
is a cheaper, more effective and eco-friendly approach for the management of Meloidogyne spp.
(Sultana et al. 2013; Becker et al. 2003). This study was planned to
identify resistant varieties of cotton against these potential pathogens and to
evaluate the synergistic effect of M.
incognita and R. bataticola
on cotton.
Materials and Methods
Collection
of cotton varieties
Thirty cotton varieties were collected from different
research stations and institutes (i.e. Cotton Research Station Multan, Vehari, Bahawalpur, Faisalabad and Cotton Research
Institute Multan). The experiments were done in research area at Department of
Plant Pathology, University of Agriculture Faisalabad, under greenhouse trial
following three sets using three replicates per experiment under completely
randomized design. Firstly, the screening of cotton varieties was done to
assess their responses against M.
incognita and R. bataticola
whereas their interaction was studied in next experiment. All the experiments
were repeated twice.
Screening
against M. incognita
The earthen pots having diameter of 20 cm were
sterilized with 4% formaldehyde solution. The soil having 6% clay, 70% sand, 3%
organic matter and 21% silt used in experiments was thoroughly mixed, air dried
and sieved (3.5 mm pore size sieve) to remove debris and stones. The soil was
also sterilized at 120°C for 20 min in an oven and then stored for two weeks at
25°C (Talavera and Mizukubo 2003). After germination,
one plant per pot was maintained. The irrigation of plants was done carefully.
The excessive irrigation or overhead watering was avoided to eliminate the risk
of nematode drying or leaching out of the soil, especially for the first few
days after nematode inoculation. M.
incognita (isolated from cotton and identified based on morphological
characteristics) was mass cultured on the roots of the susceptible tomato
variety viz. Money Maker by single egg mass culture for regular supply. Second
stage juveniles (J2s) were extracted according to procedure
described by Hussy and Barker (1973). Nematode suspension was prepared by
pouring culture into a measuring cylinder and mixed vigorously by stirring and
blowing. The counting of nematodes was done by taking 1 mL aliquots in a
counting dish, repeated thrice and total population was estimated by
multiplying the mean of three aliquots with total volume. Approximately 1000
nematodes were inoculated per pot after 60 days of planting. Root-knot galling
index rated 0 to 5 was used in experiments to study the response of cultivars
against M. incognita (Quesenberry et al.
1989; Anwar and Mckenry 2007) (Table 1).
Screening
against R. bataticola
Resistance of cotton varieties was also evaluated
against R. bataticola,
a fungus causing root rot. R. bataticola (isolated from infected cotton roots and
identified based on morphological characteristics) was cultured on PDA, 39 g
per 1000 mL of water, in a 9 cm Petri plate. After pouring and inoculation,
plates were kept at 28±2°C in an incubator (Sharma et al. 2012). The inoculation of R. bataticola was done on sixty days old
cotton plants by picking the fungal colony along with PDA with spatula at the
rate of 2 g mycelial mat/plant. The disease severity was calculated using
appropriate disease rating scale (Ruppel et al. 1979) (Table 2).
Interaction
of M. incognita and R. bataticola
A total of ten varieties were chosen, five varieties;
CM-482, FH-169, MNH-554, FH-183, BT-8 were selected on the basis of
resistant/susceptible response against M.
incognita and five varieties; FH-177, P-5, CRS-2007, FH-4243, CRIS-134 on
the basis of resistant/susceptible response against R. bataticola to assess the synergistic
effect of both pathogens. M. incognita were applied by making
holes around each plant at rate of 1 J2 /g soil. R. bataticola was inoculated by picking the fungal colony along with PDA with
spatula at the rate of 2 g mycelial mat/plant. The experiment was
conducted in three sets and the data was collected after 7, 15 and 30 days. The
parameters calculated were J3 stage, J4 stage, J2
second stage, root rot severity, dry shoot weight, fresh shoot weight, dry root
weight and fresh root weight. Data was managed by calculating means of repeated experiments
and data presented in tables are from all replicated experiments. Standard errors of mean
were calculated in Microsoft Excel 2010 and were statistically analyzed using Statistics 8.1 and
SAS 9.3 software at 5% significant level (Steel et al. 1997).
Results
Screening of cotton varieties against M. incognita
Table 1: Root-knot galling index (Quesenberry et al. 1989; Anwar et al. 2007)
Ratings |
Number of galls |
Response |
0 |
No gall |
HR |
1 |
1-2 |
R |
2 |
3-10 |
MR |
3 |
11-30 |
MS |
4 |
31-100 |
S |
5 |
˃ 100 galls per root system |
HS |
Table 2: Disease rating scale of root rot of cotton (Ruppel et al.
1979)
Scale |
Status |
Root severity |
0 |
HR |
No visible lesions on roots
and yellowing of leaves. |
1-2 |
R |
Superficial, arrested dry
lesions, at the point of inoculation, non-active lesions on tap root, no
rooting. Total infected area ˂5%(1)or 5-10%(2) |
2.1-4 |
MR |
Deep dry rot at point of
inoculation total infected area 10-25% (2.1-3) or 25-50% (3.1-4). |
4.1-6 |
MS |
Extensive rot of upper half
of tap root. Total infected area 50-75%(4.1-5)or ˃75%(5.1-6) |
6.1-8 |
S |
More than 75% of tap root
blackened, with rot extended well into the interior (6.1-7), roots usually
misshapen most of the foliage yellowed and wilted (7.1-8). |
8.1-9 |
HS |
Plant dead 100% rotted,
plants can be easily pulled from ground. |
Table 3: Screening of cotton cultivars against M.
incognita
S. No. |
Varieties |
No. of Galls |
Galling Index |
Response |
S. No. |
Varieties |
No. of Galls |
Galling Index |
Response |
1 |
BS-252 |
461.00a |
5a |
HS |
16 |
CM-482 |
171.33fghij |
5a |
HS |
2 |
S-one 886 |
127.67jkl |
5a |
HS |
17 |
NIBGE-2 |
187.67efghi |
5a |
HS |
3 |
MNH-554 |
36.67nop |
3.6d |
MS |
18 |
A-501 |
204.67efg |
5a |
HS |
4 |
FH-183 |
15.67op |
2.6e |
MR |
19 |
BH-186 |
351.00c |
5a |
HS |
5 |
PB-896 |
45.33nop |
4cd |
S |
20 |
VH-329 |
155.67ghijk |
5a |
HS |
6 |
FH-177 |
239.00de |
5a |
HS |
21 |
CRS-2007 |
146.67hijk |
5a |
HS |
7 |
FH-169 |
111.00klm |
4.6ab |
S |
22 |
S-3 |
395.00bc |
5a |
HS |
8 |
K-2129 |
267.67d |
5a |
HS |
23 |
CIM-573 |
439.33ab |
5a |
HS |
9 |
Akbar 802 |
67.67mno |
4.3bc |
S |
24 |
FH182 |
386.33bc |
5a |
HS |
10 |
MNH 886 |
193.33efgh |
5a |
HS |
25 |
BT-12 |
218.33def |
5a |
HS |
11 |
FH-142 |
407.00abc |
5a |
HS |
26 |
BT-8 |
2.67p |
1.6f |
R |
12 |
CM-615 |
81.33lmn |
4.3bc |
S |
27 |
P-5 |
132.67ijkl |
5a |
HS |
13 |
Red acala |
219.67def |
5a |
HS |
28 |
BH-172 |
386.33bc |
5a |
HS |
14 |
CRIS-134 |
111.00klm |
4.7ab |
S |
29 |
BT-10 |
144.00hijk |
5a |
HS |
15 |
FH-4243 |
168.33fghij |
5a |
HS |
30 |
P-11 |
5.33p |
2f |
MR |
Values sharing common letters in each column do not
differ significantly at P ≤ 0.05 according to least significant difference
test.
In this experiment number of galls was calculated and
results showed that the number of galls varied significantly among all
varieties. The varieties BS-252 (461) and CIM-573 (439.3) showed maximum number
of galls. The smaller number of nematode galls was counted in variety FH-183
(15.6), P-11 (5.3) and BT-8 (2.6). Overall, twenty-one varieties showed highly
susceptible response while only four varieties showed susceptible response to M. incognita. MNH-554 was moderately
susceptible variety whereas two varieties (P-11 and FH-183) were moderately
resistant. Only single variety BT-8 showed resistant response (Table 3).
Screening
of cotton cultivars against R. bataticola
Only one variety (CRIS-134) showed resistant response
against R. bataticola.
Overall, nine varieties were moderately resistant; eleven varieties were rated
moderately susceptible whereas eight varieties were susceptible to R. bataticola.
Maximum disease severity (8.1) was calculated in variety FH-177 (Table 4).
Screening
of cotton cultivars infected with Meloidogyne incognita
and Rhizoctonia bataticola
Results showed that presence of M. incognita significantly induced severe root rot in those
varieties that were resistant against R. bataticola. CRS-2007, FH-4243 and CRIS-134 were
moderately susceptible, moderately resistant and resistant against R. bataticola
but they were highly susceptible and susceptible against M. incognita, respectively (Table 3, 4). According to results taken
after 7 days of data collection shown positive increase in disease severity as
1.4% root rot severity was noted in CRS-2007, 1.3% severity in FH-4243 and 2.1%
severity in CRIS-134 with 1.33 g, 1.5 g and 1.5 g fresh root weight whereas 2.4
g, 2.3 g and 2.7 g fresh shoot weight, respectively. Number of juveniles (J2)
isolated from infected roots of varieties CRS-2007, FH-4243 and CRIS-134 were
82.2, 64.3 and 130.8, respectively (Table 5). Correlation analysis (0.976**
=Pearson’s correlation coefficient) and regression equation (y=0.0194x-0.1553)
of root-knot nematode (M. incognita)
with root rot fungus (R. bataticola) showed highly significant relationship (R2=0.9314)
between M. incognita (J2 second
stage) and R. bataticola
after 7 days at P<0.01 (Fig. 1; Table 6). Data collected after 15 days shown
3.8% disease severity in variety CRS-2007, 2.8% in FH-4243 and 4.4% in
CRIS-134. Variety FH-177 and CM-482 was highly susceptible and susceptible to M. incognita and R. bataticola with maximum disease severity,
4.6% and 4.8%, respectively. Increase in disease severity in cultivars
resistant to R. bataticola
represents the direct involvement of nematodes as the number of J2
developing stage (J3) counted in CRS-2007, FH-4243 and CRIS-134 was
29.53, 21.83 and 93.23 with 3.8 g, 3.3 g and 3 g fresh root weight and 6.1 g,
6.4 g and 5.4 g fresh shoot weight, respectively showing highly significant
correlation (0.813** =Pearson’s correlation coefficient: R2=0.4947)
between M. incognita and R. bataticola
at P˂0.01 (Table 5 and 6: Fig. 2). After 30 days no J2s were
isolated from the samples whereas number of J4 counted in varieties,
FH-4243, CRIS-134, MNH-554, resistant to R.
bataticola were 22.43, 29.17 and 7.06,
respectively. A significant relationship (0.694* =Pearson’s
correlation coefficient: R2=0.3218) was observed between nematodes
(J4) and root rot severity at P<0.05 (Table 6: Fig. 3). Varieties
that were moderately resistant (FH-183) and resistant (BT-8) against nematode
showed minimum disease severity with maximum fresh shoot weight and fresh root
weight in all experiments after 7, 15 and 30 days (Table 5).
Table 4: Screening of cotton cultivars against R.
bataticola
S. No. |
Varieties |
Severity |
Status |
S. No. |
Varieties |
Severity |
Status |
1 |
BS-252 |
6.13±0.14 d |
S |
16 |
CM-482 |
7.50±0.20b |
S |
2 |
S-one 886 |
6.97±0.08c |
S |
17 |
NIBGE-2 |
6.40±0.20d |
S |
3 |
MNH-554 |
2.13±0.14k |
MR |
18 |
A-501 |
5.43±0.24e |
MS |
4 |
FH-183 |
2.47±0.18jk |
MR |
19 |
BH-186 |
4.60±0.17f |
MS |
5 |
PB-896 |
3.07±0.08hi |
MR |
20 |
VH-329 |
4.43±0.20f |
MS |
6 |
FH-177 |
8.10±0.11a |
HS |
21 |
CRS-2007 |
5.57±0.17e |
MS |
7 |
FH-169 |
5.57±0.24e |
MS |
22 |
S-3 |
4.50±0.11f |
MS |
8 |
K-2129 |
3.57±0.08g |
MR |
23 |
CIM-573 |
5.23±0.20e |
MS |
9 |
Akbar 802 |
2.67±0.14ij |
MR |
24 |
FH182 |
6.10±0.11d |
S |
10 |
MNH 886 |
6.40±0.20d |
S |
25 |
BT-12 |
4.63±0.17f |
MS |
11 |
FH-142 |
3.43±0.20gh |
MR |
26 |
BT-8 |
5.43±0.6e |
MS |
12 |
CM-615 |
6.40±0.17d |
S |
27 |
P-5 |
7.37±0.12bc |
S |
13 |
Red acala |
3.57±0.08g |
MR |
28 |
BH-172 |
4.33±0.12f |
MS |
14 |
CRIS-134 |
1.70±0.11l |
R |
29 |
BT-10 |
5.57±0.21e |
MS |
15 |
FH-4243 |
2.20±0.15k |
MR |
30 |
P-11 |
3.57±0.12g |
MR |
Values sharing
common letters in each column do not differ significantly at P ≤0.05 according
to least significant difference test. [R= resistant, MR= moderately resistant, S=
susceptible, MS= moderately susceptible, HS= highly susceptible]
Table 5: Screening of cotton cultivars infected with M. incognita and R. bataticola
After 7 days |
||||||||
Varieties |
J2 second stage |
J2developing stage |
J4 |
Root rot |
FRW |
DRW |
FSW |
DSW |
FH-177 |
138.83±2a |
0.83±.16h |
0.00 |
2.6±0.05ab |
1.1±0.05g |
0.50±0.05f |
2.9±0.11e |
1.4±0.05d |
P-5 |
119.4±2d |
4.93±0.59g |
0.00 |
1.9±0.05cd |
1.63±0.03e |
0.83±0.03de |
2.6±0.05efg |
1.27±0.03de |
CRS2007 |
82.2±1.5f |
11.8±0.55e |
0.00 |
1.4±0.29de |
1.33±0.03f |
0.46±0.13f |
2.4±0.05fgh |
1.17±0.03de |
FH-4243 |
64.3±2g |
19.56±0.52c |
0.00 |
1.3±0.08e |
1.5±0.05e |
0.73±0.03e |
2.3±0.05gh |
1.13±0.03e |
CRIS-134 |
130.8±2.8b |
0.66±0.16h |
0.00 |
2.1±0.05bc |
1.5±0.05e |
0.73±0.03e |
2.7±0.05ef |
1.33±0.03de |
CM-482 |
132.4±1.2b |
14.43±0.29d |
0.00 |
2.7±0.05a |
1.1±0.05g |
0.53±0.03f |
2.1±0.05hi |
1.17±0.16de |
FH-169 |
125.3±0.92c |
7.47±0.29f |
0.00 |
2.3±0.05abc |
1.8±0.03d |
0.9±0.05cd |
1.93±0.03i |
0.80±0.05f |
MNH554 |
98.7±0.89e |
53.16±1.52a |
0.00 |
1.9±0.05cd |
2.1±0.05c |
1b±0.05c |
3.53±0.12d |
1.8±0.1c |
FH-183 |
55.4±2.4h |
13.37±0.96de |
0.00 |
0.7±0.37f |
2.3±0.05b |
1.06±0.03b |
4.4±0.05c |
2±0.05c |
BT-8 |
27.9±1.3i |
21.93±0.74b |
0.00 |
0.3±0.33fg |
2.5±0.05a |
1.1±0.0ab |
5.06±0.08b |
2.37±0.03b |
After 15 days |
||||||||
Varieties |
J2 second stage |
J2developing stage |
J4 |
Root rot |
FRW |
DRW |
FSW |
DSW |
FH-177 |
20.1±2.8a |
4.83±0.44g |
7.40±0.20h |
4.6±0.05b |
2.9±0.08h |
1.3±0.1f |
5.5±0.05hi |
2.7±0.05f |
P-5 |
13.5±0.31c |
17.63±0.37e |
30±0.28e |
3.3±0.05e |
3.3±0.05f |
1.53±0.03e |
5.8±0.05g |
2.83±0.03ef |
CRS2007 |
7±0.31e |
29.53±0.29c |
80.70±0.62b |
3.8±0.05d |
3.8±0.05e |
1.83±0.03d |
6.1±0.05f |
2.9±0.05def |
FH-4243 |
17.5±0.45ab |
21.83±0.76d |
44.93±0.38d |
2.8±0.05f |
3.3±0.05f |
1.6±0.05e |
6.4±0.05e |
3.1±0.05cde |
CRIS-134 |
15±0.50bc |
93.23±1.51a |
98.47±1.46a |
4.4±0.05c |
3g±0.05h |
1.47±0.03e |
5.4±0.05i |
2.67±0.03f |
CM-482 |
17.3±0.55b |
8.7±0.43f |
8.87±0.40h |
4.8±0.06a |
3.1±0.05g |
1.53±0.03e |
5.6±0.05h |
2.7±0.05f |
FH-169 |
16.7±0.72b |
16.2±0.41e |
21.23±0.46f |
4.8±0.05a |
4±0.05d |
1.97±0.03cd |
6.3±0.05e |
3.07±0.08cde |
MNH554 |
10.5±0.37d |
33.90±0.45b |
57.50±0.62c |
4.2±0.03c |
4.23±0.03c |
2.03±0.03bc |
7±0.05d |
3.37±0.03c |
FH-183 |
6±0.28e |
22.5±0.45d |
20.3±0.33f |
1.9±0.03g |
4.46±0.03b |
2.17±0.06b |
7.4±0.05c |
3.2±0.35cd |
BT-8 |
2.9±0.24f |
3.90±0.20g |
16.00±0.37g |
1.8±0.05h |
4.67±0.03a |
2.16±0.03b |
7.8±0.05b |
3.8±0.05b |
After 30 days |
||||||||
Varieties |
J2 second stage |
J2developing stage |
J4 |
Root rot |
FRW |
DRW |
FSW |
DSW |
FH-177 |
0.00 |
44.53±1.25b |
28.47±0.46a |
6.3±0.05c |
4.5±0.05g |
2.07±0.03efg |
6.93±0.08gh |
3.2±0.05ef |
P-5 |
0.00 |
33.0±1.4d |
25.47±0.29c |
5.3±0.05f |
4.1±0.05i |
1.9±0.11g |
7.5±0.05ef |
3.47±0.03de |
CRS2007 |
0.00 |
22.5±0.45f |
14.50±0.36e |
5.6±0.05e |
4.3±0.05h |
2±0.05fg |
7.9±0.05de |
3.67±0.12cd |
FH-4243 |
0.00 |
18.3±0.47g |
22.43±0.29d |
4.9±0.05g |
4.8±0.05f |
2.1±0.03ef |
7.2±0.05fg |
3.09±0.06efg |
CRIS-134 |
0.00 |
54.47±0.55a |
29.17±0.61a |
6.2±0.05c |
4.3±0.05h |
2.03±0.03efg |
6.7±0.15h |
3±0.05fg |
CM-482 |
0.00 |
36.2±0.66c |
26.83±0.21b |
6.9±0.03a |
4.2±0.05hi |
1.97±0.03fg |
6.1±0.15i |
2.8±0.05g |
FH-169 |
0.00 |
13.27±0.13h |
12.07±0.52f |
6.7±0.05b |
5±0.05e |
2.2±0.05de |
8.3±0.15d |
3.6±0.10d |
MNH554 |
0.00 |
30.23±0.52e |
7.06±0.06g |
5.9±0.03d |
5.4±0.05d |
2.33±0.05d |
9.6±0.05c |
4±0.15c |
FH-183 |
0.00 |
3.1±0.36i |
5.23±0.12h |
3.6±0.05h |
5.7±0.05c |
2.6±0.05c |
10.07±0.08c |
4.6±0.11b |
BT-8 |
0.00 |
3.10±0.05i |
7.37±0.18g |
3.3±0.05i |
6.2±0.05b |
2.83±0.03b |
11.5±0.15b |
4.9±0.05b |
Values sharing
common letters in each column do not differ significantly at P ≤0.05 according
to least significant difference test.
J= juvenile, FRW= fresh root weight, DRW= dry root
weight, FSW= fresh shoot weight, DSW= dry shoot weight
Fig. 1: Regression equation showing the effect of M. incognita and R. bataticola on root rot disease severity
Table 6: Correlation of M. incognita
with R. bataticola
Stage |
After 7 days |
J2 Second
stage |
Root rot
severity |
|
0.976** 0.000 |
|
After 15 days |
J2 Second
stage |
Root rot
severity |
|
0.813** 0.002 |
|
After 30 days |
J4 stage |
Root rot
severity |
|
0.694* 0.018 |
Upper values
indicated Pearson’s correlation coefficient;
Lower values
indicated level of significance at 5% probability.
* = Significant (P<0.05); ** = Highly
significant (P<0.01)
Fig. 2: Regression equation showing
the effect of M. incognita and R. bataticola
on root rot disease severity
Fig. 3: Regression equation showing
the effect of M. incognita and R. bataticola
on root rot disease severity
Discussion
M.
incognita is a very devastating and wide spread plant parasitic
nematode. It not only causes damage to the roots but also provide space for
entry to other soil-borne microorganisms. Cultivation of resistant varieties is
a cheaper, more eco-friendly and effective method to reduce the population of M. incognita. Zhan et al. (2018) reported that cultivars breed with high level of resistance could
reduce Meloidogyne
population below economic damage. Mohanta and Mohanty (2012) conducted experiment to screen fifty-six
okra cultivars/germplasm for their resistance to M. incognita. Present results are in line with
these findings as the thirty cotton varieties were evaluated against root-knot
nematode. Three varieties showed moderately resistant and resistant responses
with the lowest nematode population whereas all other varieties showed
susceptible responses with poor vigor and growth. Limited work has been done
and reported on the screening of cotton varieties against M. incognita. This study is also supported by Anwar and Mckenry (2007) that there are few investigations on
screening of cotton varieties against M.
incognita. However, different researchers have reported varying levels of
resistance and susceptibility on okra varieties against M. incognita (Sheela et al. 2006; Vinícius-Marin et al. 2017; Silva et al. 2019). Results in this study showed that susceptible
varieties had more number of females and number of galls as compared to
resistant cultivars. The findings in this study are in line with findings
reported by Hussain et al. (2014). They found higher number of eggs, galls and females
per plant in susceptible cultivars. After the entrance in roots, various
compatible and incompatible reactions occur because of resistance (R) genes
that lead to the visible reactions observed in the plant cells (Davis et al. 2000). The study concurs with the
findings of Klink and Matthews (2009) and Ali and Abbas (2016) where they
concluded that root-knot nematode infected all genotypes with different level
of pathogenicity, which might be due to R genes. Mechanism of M. incognita infection and response of
hosts had been elaborated by many researchers (Bendezu
and Starr 2003; Williamson and Kumar 2006; Gheysen
and Vanholme 2007; Ali et al. 2018). In this study, one variety was resistant and nine
varieties were moderately resistant. Pande et al. (2004) supported the present
evidences by conducting a trial on forty-seven chickpea germplasm
against R. bataticola
and among them 3 germplasm were resistant, 22
moderately resistant, 19 susceptible and 3 highly susceptible. Similar study
was conducted by Khan et al. (2013)
for sixty chickpea germplasm evaluation against R. bataticola,
out of which 9 were resistant, 10 moderately resistant, 7 moderately
susceptible, 17 susceptible and 17 highly susceptible.
Results from this study revealed that the presence of M. incognita significantly induced root
rot severity in cotton varieties that were resistant against R. bataticola.
This study concurred with Wheeler et al. (2019) that demonstrated the presence of M. incognita was favorable for the development of wilt symptom. Giant cells caused by nematodes produce metabolites that are significant source of food for R. bataticola. These swellings in roots
increase fungal activity within root tissues and after colonization, the
fungus moved into xylem tissues and caused wilting symptom (Hua
et al. 2019). In this
study, maximum disease severity was noted at second stage (J2) of
M. incognita. Correlation and
regression equations for M. incognita and R. bataticola proved the significance of their interaction
statistically. Interaction between nematode and fungi was first
reported on cotton by Atkinson (1982). Al-Hazmi
and Al-Nadary (2015) reported that in the presence of M. incognita, the maximum severity caused by R. solani was observed in Phaseolus vulgaris. Various studies has been conducted by several
scientists on nematode and fungus interaction in various crops (Back et al. 2002; Back et al. 2006; Abuzar 2013; Safiuddin et al. 2014). Al-Hazmi and Al-Nadary (2015) reported the similar results that
synchronized inoculation of fungus and nematode increased the disease index of
fungus and root gall caused by nematodes. The cotton varieties resistant
against M. incognita showed minimum
disease severity with maximum fresh shoot weight and fresh root weight whereas
there were variations in shoot-root weight in susceptible and resistant
cultivars. Zwart et al. (2019) elaborated
that affected plants produce more roots to overcome the limitations caused by
nematodes and root efficiency reduced in the damage caused by root-knot
nematode resulted in poor
root-shoot ratio, the developing females withdraw the nutrients causing further
damage, between the inoculum level and root weight a significant direct relationship
was found, as the inoculum density increased, the root weight also enhanced. Setty and Wheeler (1968) and Afshar
et al. (2014) explained that the
higher root weight in affected plants might be due to amino acids, more
tryptophan and larger amount of growth substance. It had inverse impact
on shoot length. In this study inverse relationship was shown between root and
shoot weight. The findings are contradictory to the hypothesis of Wareing (1970), that shoot and root are dependent on each
other for carbohydrates, growth substances and nutrients. However, any reduction in root growth limit the shoot growth or vice
versa.
Conclusion
This study concluded that interaction of M. incognita and R. bataticola disturbed the coordination
between roots and shoots leading to poor plant growth. The disease severity
caused by R. bataticola
with the presence of M. incognita
increased to hundred percent. Thus, the cultivation of resistant and moderately
resistant cotton cultivars in the field would help in reducing disease
severity. Further studies are needed to investigate the interaction and
resistant mechanism(s) as indicated in this study.
Author Contributions
MAK carried out research work. SAK and MYW
provided technical support. HR, NA, RB, WA, MI, MA, MAZ, QS, RMI, UW and AM
helped in writing the manuscript.
References
Abuzar S
(2013). Antagonistic effects of some fluorescent Pseudomonas strains against
root rot fungi (Rhizoctonia solani and Fusarium
oxysporum) and root-knot nematodes (Meloidogyne incognita) on chili (Capsicum
annum). World Appl
Sci J 27:1455‒1460
Afshar FJ, N Sasanelli,
S Hosseininejad, ZT Maafi
(2014). Effects of the root-knot
nematodes Meloidogyne incognita and M. javanica on olive plants growth in
glasshouse conditions. Helminthologia 51:46‒52
Agrios GN (2005). Plant Pathology, 5th
edn. Elsevier Academic Press, London
Al-Hazmi AS, SN Al-Nadary (2015). Interaction between Meloidogyne incognita
and Rhizoctonia solani on
green beans. Saudi J Biol Sci 225:570‒574
Ali MA, A Abbas
(2016). Analysis of reporter proteins GUS and DsRed
driven under the control of CaMV35S promoter in syncytia induced by beet cyst
nematode Heterodera schachtii in
Arabidopsis roots. Adv Life Sci
3:89‒96
Ali MA, MS Anjam,
MA Nawaz, HM Lam, G Chung (2018). Signal transduction in plant–nematode
interactions. Intl J Mol Sci
19:1648
Anwar SA, MV Mckenry (2007). Variability in reproduction of four populations of Meloidogyne incognita on six cultivars of cotton.
J Nematol
39:105‒110
Atilano RA, JA Menge, SD Van Gundy
(1981). Interaction between Meloidogyne arenaria and Glomus fascicuqlatus in grape. J Nematol 13:52
Atkinson GF (1892). Some
diseases of cotton. Bulletin, Alabama Agricultural Experiment Station,
p: 19‒29
Back MA, PPJ Haydock,
P Jenkinson (2002). Disease complexes involving plant
parasitic nematodes and soilborne pathogens. Plant Pathol
51:683‒697
Back MA, PPJ Haydock,
P Jenkinson (2006). Interactions
between the potato cyst nematode Globodera rostochiensis and diseases caused by Rhizoctonia solani AG3
in potatoes under field conditions. Eur
J Plant Pathol 114:215‒223
Becker JO, V Morton, D Hofer (2003). Abamectin
seed coating: A new nematicide plant protection tool.
J Nematol
35:324
Bendezu IF, J Starr (2003). Mechanism of resistance to Meloidogyne arenaria in
the peanut cultivar. J Nematol
35:115‒118
Cook CG (1997). Tolerance
to Rotylenchulus reniformis
and resistance to Meloidogyne incognita race 3 in high-yielding breedinglines of upland cotton. J Nematol 29:320‒326
Davis EL, RS Hussey, TJ Baum, J Bakker, A Schots, MN Rosso, P Abad (2000). Nematode
parasitism genes. Annu Rev Phytopathol
38:365–396
Economic
Survey of Pakistan (2018–2019). In: Government of Pakistan. Finance Division Economic Adviser's Wing,
Islamabad, Pakistan
Edin E,
M Gulsher, M Andersson Franko, JE Englund, A Flöhr, J Kardell,
M Viketoft (2019). Temporal interactions between
root-lesion nematodes and the fungus Rhizoctonia solani lead to reduced potato yield. Agron J 9:361
Gheysen G, B Vanholme (2007). RNAi from plants
to nematodes. Trends Biotechnol 25:89‒92
Hua
GKH, P Timper, P Ji (2019).
Meloidogyne incognita intensifies the severity of Fusarium wilt on watermelon caused by Fusarium oxysporum f.
sp. niveum.
Can J Plant Pathol
41:261‒269
Hussain MA, T Mukhtar, MZ Kayani (2014). Characterization of
susceptibility and resistance responses to root-knot nematode (Meloidogyne incognita) infection in okra germplasm. Pak
J Agric Sci 51:309–314
Hussy RS, KR Barker (1973). Comparison of methods for collecting inocula of Meloidogyne spp., including a new technique. Plant Dis 57:1025‒1028
Iqbal
M, MZ Iqbal, RSA Khan, K Hayat (2012). Comparison of obsolete and modern varieties in view to stagnancy in
yield of cotton (G. hirsutum L.). Asian J Plant Sci
4:374‒378
Kellam
MK, NC Schenck (1980). Interactions
between a vesicular-arbuscular mycorrhizal
fungus and root-knot nematode on soybean. Phytopathology
70:293–296
Khan MA, SA Khan, I Haq, R Waseem (2017). Root
Rot Disease Complex of Cotton: A Menace to Crop in Southern Punjab and its
Mitigation through Antagonistic Fungi. Pak
J Zool 49:1817‒1828
Khan RA, AT Bhat, K Kumar
(2013). Screening of Chickpea germplasm against dry root rot caused by Rhizoctonia bataticola (Taub.) Butler. Asian
J Pharm Clin Res 6:211‒212
Kirkpatrick TL (1989). Response of four root
knot nematode/Fusarium
wilt resistant cotton breeding lines when grown in a field infested with both Meloidogyne incognita and Fusarium oxysporum f.sp.
Vasinfectum,
p:41. In: Proceedings of Beltwide Cotton Products Research Conference, January 2‒7, 1989. National Cotton Council of America,
Memphis, Tennessee, USA
Klink VP, BF Matthews (2009). Emerging
approaches to broaden resistance of soybean to soybean cyst nematode as
supported by gene expression studies. Plant
Physiol 151:1017‒1022
Maqbool MA (1987). Classification and
distribution of plant parasitic nematodes in Pakistan. Pak J Nematol
5:15‒17
Mohanta S, KC Mohanty
(2012). Screening of okra germplasms/varieties
for resistance against Meloidogyne incognita. J Plant Prot
Environ 9:66‒68
Nazir SL
(2007). Control of root rot of cotton with compost rice straw fortified with
antagonistic fungi. J Nematol
35:324
Pande S,
KG Kishore, JN Rao (2004). Evaluation of Chickpea line for resistance
to dry root rot caused by Rhizoctonia bataticola. ICRISAT, Hyderabad, India
Powell NT (1971). Interactions
between nematodes and fungi in disease complexes. Annu
Rev Phytopathol 9:253–274
Quesenberry KH, DD Baltensperger, RA Dunn,
CJ Wilcox, SR Hardy (1989). Selection for tolerance to root
knot nematode in red clover. Crop Sci 29:62‒65
Robinson AF (1997). Resistance
to Meloidogyne incognita race 3 and Rotylenchulus reniformis in
wild accessions of Gossypium hirsutum and G. barbadense
from Mexico. Suppl. J Nematol 29:746‒755
Ruppel EG,
CL Schneider, RJ Hecker, GJ Hogaboam
(1979). Creating epiphytotics
of Rhizoctonia root rot and evaluating for resistance
to Rhizoctonia solani in sugarbeet field plots. Agriculture Resource Centre Baghadad, Iraq
Safiuddin, SA Tiyagi, R Rizvi, I Mahmood (2014). Biological control of
disease complexes involving Meloidogyne incognita
and Rhizoctonia solani
on growth of okra through microbial inoculants. J Microbiol Biotechnol
Res 4:46‒51
Setty KGH, AW Wheeler (1968). Growth substances in roots of tomato (Lycopersicon esculentum
Mill.) infected with root-knot nematodes (Meloidogyne spp.). Ann Appl Biol 61:495‒501
Sharma
M, R Ghosh, RR Krishnan, UN Nagamangala,
SK Chamarthi, RK Varshney,
S Pande (2012). Molecular and morphological diversity in Rhizoctonia
bataticola isolates causing dry root rot of
chickpea (Cicer arietinum
L.) in India. Afr J Biotechnol 8949‒8959
Sheela MS, R Malu, S Shaiju (2006). Screening of okra varieties for resistance against Meloidogyne incognita. Ind J Nematol 36:292‒293
Shuli F, AH Jarwar, X
Wang, L Wang, Q Ma (2018). Overview of the cotton in Pakistan and its future prospects.
Pak J Agric Res
31:396–407
Siddique IA,
SS Shaukat, A Khan (2004). Differential impact of some Aspergillus spp on Meloidogyne javanica biocontrol by Psedumonas flourescens. J
Appl Microbiol 39:74‒83
Silva EHC, RS Soares,
HO Borges, CA Franco, L T Braz, PLM Soares (2019). Quantification of the damage caused by Meloidogyne enterolobii in okra. Pesqui Agropecu Bras
54; Article e00050
Singh ND (1975). Effect of inoculums levels and plant
age on pathogenecity of Meloidogyne incognita and Rotylenchulus reniformis to tomato and lettuce. Plant Dis 9:905‒908
Srinivas P, S Ramesh, P Sharma, N Reddy, B Pushpavathi
(2017). Effect of temperature
on Rhizoctonia bataticola
and dry root rot in chick pea. Intl
J Curr Microbiol Appl Sci 6:3349‒3355
Steel RG, JH Torrie,
DA Deekey (1997). Principles and
Procedures of Statistics. A Biometrical approach,
3rd edn. McGraw Hill Book Co. Inc.,
New York, USA
Sultana R, BA Bugio, GR Phanwar, WA Phanwar, S Kumar
(2013). Effect of excessive
irrigation on the breakdown of root rot diseases in cotton crop from Sakrand Sindh. Sind
Uni Res J 45:15‒16
Talavera M, T Mizukubo
(2003). Influence of soil conditions, spore densities and nematodes age on Pasteuria penetrans
attachment to Meloidogyne incognita. Span J Agric Res 1:57‒63
Tu
CC, YH Cheng (1971). Interaction of Meloidogyne javanica and Macrophomina phaseoli in kenaf root rot. J
Nematol 3:39
Vinícius-Marin
M, LS Santos, LA Gaion,
HO Rabelo, CA Franco, GM Diniz,
LT Braz (2017). Selection of
resistant rootstocks to Meloidogyne enterolobii
and M. incognita for okra (Abelmoschus esculentus).
Chil J Agric Res
77:58‒64
Wareing PF
(1970). Growth and its co-ordination in trees. In:
Physiology of Tree Crops, Luckwill LC, CV Cutting
(Eds.). Symp., Long Ashton Res. Sta. Uni. Bristol, Acad. Press, New
York, USA
Wheeler DL, J Scott, JKS Dung, DA Johnson
(2019). Evidence of a trans-kingdom plant disease complex
between a fungus and plant-parasitic nematodes. PLoS One 14; Article e0211508
Williamson
VM, A Kumar (2006). Nematode resistance in plants: The battle underground. Trends Genet 22:396‒403
Zhan LP, DI Zhong,
DL Peng, PE Huan, LA Kong,
SM Liu, LI Ying, ZC Li, WK Huag (2018). Evaluation of
Chinese rice varieties resistant to the root-knot nematode Meloidogyne graminicola. J Integr Agric
17:621‒630
Zwart RS, M Thudi, S Channale, PK Manchikatla, RK Varshney, JP Thompson (2019). Resistance to plant-parasitic nematodes in chickpea:
Current status and future perspectives. Front
Plant Sci 10; Article 966