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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.
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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 INTRODUCTION: 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 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. • 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, Botrytiscinerea, 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: • 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. SRI CONT Evaluation of most promising isolates against fungal pathogens KAI-35Vs FOC CAI-87 Vs MP Charcoal rot in Sorghum Sclerotium infection in chickpea KAI-161 Vs Botrytis CAI-97 Vs RB6 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. CAI-87,-54 Kai-35,-161 An uprooted chickpea plant with Fusarium infection Isolates positive for lipase production *Corresponding author Dr S Gopalakrishnan, Email:s.gopalakrishnan@cgiar.org