Evaluation of antagonistic and plant growth promoting properties of actinomycetes isolated from herbal vermicompost

*Corresponding author Dr S Gopalakrishnan, Email: s.gopalakrishnan@cgiar.org

SRICONT

INTRODUCTIONINTRODUCTION: : Pesticides are used extensively in agriculture to control insect pests and plant Pesticides are used extensively in agriculture to control insect pests and plant pathogens however; their use has led to environmental pollution and health hazards. Hence there is an urgent pathogens 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 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. 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 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.toxins and antibiotics which not only control plant diseases but also help in growth and vitality of the plant.

Evaluation of the Herbal vermicompost actinomycetes isolates against Fungal pathogens of Chickpea and Sorghum

Publications: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 2011Gopalakrishnan, et al., (2011). Evaluation of Actinomycetes isolated from herbal vermicompost for biological control of Fusarium wilt of chickpea. Crop Protection DOI j.cropro.2011.03.006Gopalakrishnan, 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.

K. Deepthi*, P. Humayun, V. Srinivas, J. Simi, M. Sreevidya, G. Alekhya and S. K. Deepthi*, P. Humayun, V. Srinivas, J. Simi, M. Sreevidya, G. Alekhya and S. GopalakrishnanGopalakrishnan

MATERIALS AND METHODS:MATERIALS AND METHODS:•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.

RESULTS: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.

Evaluation of most promising isolates against fungal pathogens

CAI-87 Vs MP KAI-35 Vs FOC

KAI-161 Vs Botrytis CAI-97 Vs RB6

Isolates Zone of inhibition in mm

FOC 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 -

CAI-97 7.6 13.5 12.7 4.0 8.0 0.0 -

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 +

An uprooted chickpea plant with Fusarium infection

Isolates positive for lipase production

CAI-87,-54 Kai-35,-161

0.0

5.0

10.0

15.0

20.0

25.0

CAI-155 KAI-35 KAI-161

Promising Actinomycetes

Zo

ne

of

inh

ibit

ion

(in

mm

)

FOC M. phaseolina B.cinerea RB-6 RB-24 RB-115

Sclerotium infection in chickpea Charcoal rot in Sorghum