Actinomycetes and their secondary metabolites to control multiple pathogens of chickpea and sorghum S. Gopalakrishnan* and GV Ranga Rao S. Gopalakrishnan* and GV Ranga Rao ICRISAT, Patancheru, Hyderabad, Andhra Pradesh, India * Corresponding author: SRI CONT INTRODUCTION In the present study, 25 different herbal vermicomposts were screened for actinomycetes that contain antifungal potential against Fusarium wilt and collar rot of chickpea (caused by Fusarium oxysporum f. sp. ciceri and Sclerotium rolfsii, respectively) and charcoal rot of sorghum (caused by Macrophomina phaseolina ) and anti-insect potential against Helicoverpa armigera, the polyphagous pest of many crops. The promising ones were selected further for metabolite purification studies. MATERIALS AND METHODS  Prominent actinomycetes isolated with SCA by spread plate methods.  In-vitro antifungal activity by dual-culture assay.  In-vivo anti-insect activity by bioassay (on 3 rd instar Helicoverpa larvae)  Evaluated for PGP traits on respective selective media.  Actinomycetes identified by 16S rDNA analysis.  Metabolite production capability by solvent partitioning and bioassay.  Partial purification done by SPE and open column chromatography. RESULTS  Three most promising actinomycetes (CAI-21, CAI-26 and MMA-32) based on biocontrol and PGP traits were further studied  CAI-21 was identified as Streptomyces albus, while CAI-26 and MMA-32 were identified as S. champavatii and S. roseoviolaeus, respectively.  Culture filtrates of all the three actinomycetes completely inhibited FOC but not M. phaseolina completely. However, all the culture filtrates inhibited another pathogen of chickpea, Sclerotium rolfsii which causes collar rot.  Culture filtrates of all the actinomycetes showed 58-78% mortality over control.  Upon further fractionation of the culture filtrates of one of the actinomycetes (CAI-21) by open column chromatography, only 80% MeOH fraction showed inhibition of FOC. Molecular identification of the potential actinomycetes Control CA1-17 The list of herbal vermicomposts used in this study Jatropha curcas, Annona squamosa, Parthenium hysterophorus, Oryza sativa, Gliricidia sepium, Adhatoda vasica, Azadirachta indica, Capsicum annuum, Calotropis gigantea, Calotropis procera, Datura metal, Allium sativum, Zingiber officinale, Ipomoea batatas, Momordica charantia, Moringa oleifera, Argyranthemum frutescens, Nerium indicum, Allium cepa, Curcuma aromatica, Pongamia pinnata, Abacopteris multilineata, Nicotiana tabacum, Tridax procumbens and Vitex negundo The effect of culture filtrates of actinomycetes on FOC The effect of culture filtrates of actinomycetes on S. rolfsii The effect of culture filtrates of actinomycetes on H. armigera Fractionation of culture filtrates of CAI-21 on an open column chromatography: on FOC Strains Matched withNBAIM ACC No CAI-21 Streptomyces albus NAIMCC-B CAI-26 Streptomyces champavatii NAIMCC-B MMA-32 Streptomyces roseoviolaeus NAIMCC-B Biocontrol and PGP traits of the actinomycetes On FOC On M. phaseolina On S. rolfsii The effect of culture filtrate of CAI-21 on various pathogens