Primary Study on Induction and Characteristics of Dimethachlon-resistant Strains of Coniothyrium minitans

Six dimethachlon-resistant mutants of Coniothyrium minitans were obtained by ultraviolet irradiation and chemical-taming in order to acquire strains being able to integrate with dimethachlon against sclerotinia rot diseases. The results of characteristics of mutant strains showed that growth rates of mutant strains (colony diameter 57.00 ~62.75 mm, biomass 6.38 ~8.63 mg/mL) except D-1 were larger than parent strain (colony diameter 54.00 mm, biomass 5.91 mg/mL); spore yields of most mutant strains (logarithm of spore yields 7.33 ~8.16) were less than parent strain (8.40); EC50 values of mutant strains were 2.23 ~191.84 folds higher than parent strain; only mutant strains D-3 and U-6 had slight chitinase activities and glucanase activities of mutant strains(9.18 ~17.61 U) but U-4 enhanced compared with parent strain(8.96 U).In general, mutant strain U-6 had not only higher chitinase activities but also possessed chitinase activities. Besides, U-6 maintained faster growth rate, so it is a strain worthy of further development.