Exploring soil biology to understand high yields due to

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Transcript Exploring soil biology to understand high yields due to

Evaluation of antagonistic and plant growth promoting properties of actinomycetes isolated from
herbal vermicompost
K. Deepthi*, P. Humayun, V. Srinivas, J. Simi, M. Sreevidya, G. Alekhya and S. Gopalakrishnan
Evaluation of the Herbal vermicompost actinomycetes isolates against Fungal pathogens of Chickpea and
Sorghum
Isolates
INTRODUCTION: Pesticides are used extensively in agriculture to control insect pests and plant pathogens
Zone of inhibition in mm
MP
B.cinerea
*RB-6
*RB-24
*RB-115
S.rolfsii
CAI-13
7.2
12.2
14.0
10.0
6.7
0.0
+
CAI-54
6.1
2.8
0.0
1.0
1.0
0.0
-
CAI-84
5.8
0.0
2.0
0.0
0.0
0.0
-
CAI-85
12.0
7.1
11.7
3.7
6.0
0.0
-
CAI-87
15.4
11.7
13.7
5.3
6.0
0.0
-
CAI-93
6.0
9.8
11.3
7.3
9.7
7.0
-
MATERIALS AND METHODS:
CAI-97
7.6
13.5
12.7
4.0
8.0
0.0
-
•The herbal vermicompost samples have been spread plated on starch casein agar and the most prominent
isolates have been selected and evaluated for their biocontrol and PGP traits.
•The initial screening has been done by performing dual culture assay (against plant pathogens of chickpea
and sorghum viz. Sclerotium rolfsii, Rhizoctonia bataticola (three strains viz. RB-6, -24 and -115) Fusarium
oxysporum f.sp. ciceri, Botrytis cinerea, and Macrophomina phaseolina causes collar rot, dry root rot, Fusarium
wilt, Botrytis grey mould diseases in chick pea and charcoal rot in sorghum, respectively).
•The isolates have also been evaluated for their biocontrol and PGP traits such as lipases, protease, cellulase,
siderophore, HCN, Chitinase and Indole acetic acid production. as well as wilt sick field conditions.
•The promising isolates against Rb-6, 24 &115 have been further evaluated by Blotter paper assay method.
•The isolates which showed greater antagonistic activity have been further evaluated for their secondary
metabolite production.
CAI-104
6.2
0.0
10.5
2.3
1.0
0.0
-
CAI-132
10.8
7.0
13.3
3.0
2.3
0.0
-
CAI-134
5.0
0.0
6.7
0.0
1.7
0.0
-
CAI-140
8.8
14.7
18.5
4.0
8.0
0.0
-
CAI-155
10.0
14.3
15.7
10.3
12.0
0.0
-
KAI-35
13.9
21.1
13.0
12.7
14.0
13.3
+
KAI-161
14.3
20.1
14.3
13.7
15.3
14.0
+
however; their use has led to environmental pollution and health hazards. Hence there is an urgent need to look for an
alternative, which are less toxic, environment friendly, economical and which can effectively control insect pests and diseases.
One of the most promising area of interest is biological control. Actinomycetes play a greater role in biological control as they
produce many extracellular metabolites like toxins and antibiotics which not only control plant diseases but also help in
growth and vitality of the plant.
RESULTS:
•A total of 15 have been studied for their activity, out of which 10 actinomycetes (CAI-13, -85, -87, -93, -97,140,-155 and KAI-35, -161, -180) were found to have broad spectrum activity against all fungal pathogens.
•Almost all the isolates have been found to utilize cellulose, lipids, proteins, chitin and produced
siderophore, indole acetic acid and hydrogen cyanide.
•The following cultures, CAI-13, -85, -87,-155, KAI-35,-161 &180 prevented infection of chickpea roots by
Rb series.
Zone of inhibition (in mm)
FOC
25.0
20.0
15.0
10.0
5.0
0.0
CAI-155
KAI-35
KAI-161
SRI
CONT
Promising Actinomyce te s
FOC
M. phaseolina
B.cinerea
RB-6
RB-24
RB-115
Evaluation of most promising isolates against fungal pathogens
CAI-87 Vs MP
KAI-35 Vs FOC
Sclerotium infection in chickpea
KAI-161 Vs Botrytis
An uprooted chickpea plant with Fusarium infection
Charcoal rot in Sorghum
CAI-97 Vs RB6
CAI-87,-54
Kai-35,-161
Isolates positive for lipase production
Publications:
Gopalakrishnan, et al., (2011). Managing soil-borne plant pathogenic fungi using actinomycetes isolated from herbal
vermicompost. Submitted in “World J of Microbiology and Biotechnology” on 19th Mar 2011
Gopalakrishnan, et al., (2011). Evaluation of Actinomycetes isolated from herbal vermicompost for biological control
of Fusarium wilt of chickpea. Crop Protection DOI j.cropro.2011.03.006
Gopalakrishnan, et al., (2010). Evaluation of bacteria isolated from rice rhizosphere for biological control of sorghum
caused by M. phaseolina. World J of Microbiology and Biotechnology
Gopalakrishnan, et al., (2010). Efficacy of Jatropha, Annona and Parthenium biowash on Sclerotium rolfsii, FOC and M.
phaseolina pathogens of chickpea and sorghum. African J of Biotechnology 9 (47) 8048-8057.
*Corresponding author Dr S Gopalakrishnan, Email: [email protected]