[Antagonistic mechanisms of trichoderma spp. against Phytophthora nicotianae].

Antagonistic mechanisms of Trichoderma viride M3, Tv04-2, and T. harzianum ThB, were studied against Phytophthora nicotianae, the pathogen of stem blight disease on Schizonepeta tenuifolia by dual-culture, hydrolase activity, volatile and nonvolatile substances. Results indicated that competitive, mycoparasitism and antagonism were the antagonistic mechanisms of three Trichoderma spp. against P. nicotianae. Hydrolase activity showed that M3 was the highest for beta-1, 3-glucanases activity while ThB was the highest for proteases activity among the three T. strains, and they could produce volatile and non-volatile substances, also.