Microbial antagonism to Neovossia indica, causing Karnal bunt of wheat

The potentiality of fungal, bacterial and actinomycete biocontrol agents is olated from soil was investigated against Neovossia indica. Culture filtrat es of Trichoderma pseudokoningii, T. lignorum, T. koningii, Gliocladium ros eum, G. deliquescens, G. virens, fluorescent pseudomonad isolate (FP-VII), bacterial isolate Bact-II and an actinomycete isolate act-V, inhibited germ ination of teliospore and secondary sporidia of Karnal bunt fungus. Bioassa y test of the chloroform extracts of antagonists spotted on TLC plates indi cated the presence of bands of different Rf values. Three bands showing inv olvement of atleast three antifungal compounds in case of T. lignorum, T. k oningii, T. pseudokoningii, FP isolate (FP-VII), Bact-II and actinomycete i solate Act-V were observed. Bioassay of one of the purified compounds of T. koningii and T. pseudokoningii inhibited the mycelial growth of N. indica at 1000 and 500 ppm respectively while the compound from T. lignorum showed inhibition at 100 ppm.