Madi, L., Dept. Plant Pathol. and Microbiol., Hebrew University of Jerusalem, Fac. Agric., Food Environ. Qual. S., Rehovot 76100, Israel
Katan, T., Department of Plant Pathology, ARO, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Katan, J., Dept. Plant Pathol. and Microbiol., Hebrew University of Jerusalem, Fac. Agric., Food Environ. Qual. S., Rehovot 76100, Israel
Henis, Y., Dept. Plant Pathol. and Microbiol., Hebrew University of Jerusalem, Fac. Agric., Food Environ. Qual. S., Rehovot 76100, Israel

Ten wild-type strains and two benomyl-resistant mutants of Talaromyces flavus were examined for theft ability to secrete the cell wall-degrading enzymes chitinase, β-1,3-glucanase, and cellulase, to parasitize sclerotia of Sclerotium rolfsii, to reduce bean stem rot caused by S. rolfsii, and to secrete antifungal substance(s) active against Verticillium dahliae. The benomyl-resistant mutant Ben(R)TFI-R6 overproduced extracellular enzymes and exhibited enhanced antagonistic activity against S. rolfsii and V. dahliae compared to the wild-type strains and other mutants. Correlation analyses between the extracellular enzymatic activities of different isolates of T. flavus and their ability to antagonize S. rolfsii indicated that mycoparasitism by T. flavus and biological control of S. rolfsii were related to the chitinase activity of T flavus. On the other hand, production of antifungal compounds and glucose-oxidase activity may play a role in antagonism of V. dahliae by retardation of germination and hyphal growth and melanization of newly formed microsclerotia.