Abstract:

Disposed with UV., the spores of Trichoderma strains were cultivated in media adding high concentration of Trichoderma metabolites to get high antibiotic-production mutants, taking Rhizoctonia solani as indicator, and using confront culture and metabolites plate culture methods. 6 mutants with strong inhibitory action to Rhizoctonia solani were screened. According to the activity of their fermentation liquid, high producing antibiotic mutants, TD103-UV-4 and TD103-UV-13 with good genetic stability, were gained, and the growth rates were 1.86 and 1.95 times compared with the original strain respectively, and the activity of fermented product improved obviously. The inhibitory rate of metabolites produced by TD103-UV-4 against RS was more than 80%, and the antibiotic production capacity increased by 47.1%, meanwhile, its metabolites had a strong inhibition against other phytopathogenic fungi, such as Botrytis cinerea.