葡萄胶孢炭疽菌对3种麦角甾醇脱甲基抑制剂类杀菌剂的敏感性

系统比较了从云南省主要葡萄产区采集的57株葡萄胶胞炭疽菌Colletotrichum gloeosporioides对三唑类脱甲基抑制剂烯唑醇、腈菌唑及咪唑类脱甲基抑制剂咪鲜胺的敏感性、交互敏感性及敏感性与生存适合度的相关性等指标。结果表明:供试菌株对咪鲜胺的EC50值在0.01~1.58 mg/L之间,高于其对烯唑醇(EC50值为0.05~25.45 mg/L)和腈菌唑(EC50值为0.49~192.93 mg/L)的敏感性;部分菌株对烯唑醇和腈菌唑的敏感性显著降低,而对咪鲜胺仍保持较高的敏感性;供试菌株对烯唑醇和腈菌唑的敏感性具有显著的相关性,而对咪鲜胺的敏感性与对烯唑醇和腈菌唑的敏感性之间则无显著相关性。低敏感性菌株的致病力和菌落生长速率与敏感菌株无显著差异,具有较高的生存适合度。

Sensitivity of Colletotrichum gloeosporioides causing grape anthracnose to three sterol demethylation inhibitor (DMI) fungicides

The sensitivity,cross sensitivity,the relationship of sensitivity and fitness of 57 isolates of Colletotrichum gloeosporioides (Penz.) Penz.& Sacc.,collected from main grape production districts of Yunnan Province,to diniconazole,myclobutanil and prochloraz were tested.The results indicated that the EC₅₀ values of all isolates to prochloraz ranged from 0.01 mg/L to 1.58 mg/L,lower than that to diniconazole (0.05-25.45 mg/L) and myclobutanil (0.49-192.93 mg/L).Based on frequency distribution of EC₅₀ values of C.gloeosporioides populations to the three sterol demethylation inhibitor (DMI) fungicides,it was revealed that sensitivity of some isolates to diniconazole and myclobutanil had significantly decreased,but almost all isolates still kept higher sensitivity to prochloraz.The sensitivity correlation analysis for the isolates to the three DMI fungicides showed that the sensitivity of isolates to diniconazole and myclobutanil had remarkable correlation,however there were no correlation between prochloraz and diniconazole (or myclobutanil).There was no significant difference between low sensitive isolates and sensitive isolates on pathogenicity and colony growth,which indicated that low sensitive isolates still had relatively high survival fitness.