三七圆斑病菌槭菌刺孢对嘧菌酯、咪鲜胺和苯醚甲环唑的敏感性及生存适合度分析

采用菌丝生长速率法测定了采自云南省5个三七主要产区的34株三七圆斑病原菌槭菌刺孢Mycocentrospora acerina (R. Hartig) Deighton对嘧菌酯、咪鲜胺和苯醚甲环唑的敏感性，并对不同敏感性菌株进行了生存适合度测定。结果表明:咪鲜胺、嘧菌酯及苯醚甲环唑对所有供试槭菌刺孢的菌丝生长均有明显的抑制作用，3种杀菌剂的EC₅₀值分别在0.03~1.91 mg/L、0.18~2.36 mg/L和0.45~2.15 mg/L之间，即该菌株对咪鲜胺的敏感性对高于嘧菌酯和苯醚甲环唑；低敏感性菌株的致病力和菌丝生长速率与敏感性菌株间无显著差异，说明供试槭菌刺孢菌株在当地均具有较高的生存适合度。

Sensitivity and fitness analysis of round spot of Panax notoginseng Mycocentrospora acerina to azoxystrobin, prochloraz and difenoconazole

The sensitivities of 34 strains of Mycocentrospora acerina to azoxystrobin, prochloraz and difenoconazole were tested using the mycelium growth rate method, the strains were isolated from 5 major origins of Panax notoginseng in Yunnan Province. The survival fitness was also analyzed. The results showed that those fungicides had high inhibition effect on the mycelium growth of strains. The EC₅₀ values of prochloraz, azoxystrobin and difenoconazole to all tested strains are in the range of 0.03-1.91 mg/L, 0.18-2.36 mg/L and 0.45-2.15 mg/L, respectively. The sensitivities of all strains to prochloraz were higher than that of azoxystrobin and difenoconazole. The difference of mycelial growth for the sensitive and the insensitive strains was not significant, which demonstrated that all strains showed high survival fitness in field.