禾谷镰孢菌对戊唑醇敏感基线的建立和不同杀菌剂的交互抗性

The sensitive baseline of Fusarium graminearum to tebuconazole and cross resistance against diverse fungicides

为了明确禾谷镰孢菌对三唑类杀菌剂戊唑醇的敏感性及该药剂与其他杀菌剂的交互抗性,采用菌丝生长速率法测定了河南、山东和河北等不同地区的120个禾谷镰孢菌单孢菌株对戊唑醇的敏感性,同时测定了10株敏感菌株对异菌脲、福美双、百菌清、苯醚甲环唑和多菌灵的交互抗药性。结果表明:戊唑醇对禾谷镰孢菌的菌丝生长具有明显的抑制作用,EC50范围为0.007 2～0.200 7μg/mL,最大值与最小值相差27.875倍,平均值为(0.102 6±0.045 4)μg/mL,其敏感性频率呈近似正态分布,可作为禾谷镰孢菌对戊唑醇的相对敏感性基线。戊唑醇与上述不同作用机制杀菌剂之间相关系数低,均无交互抗性。

120 strains of Fusarium graminearum collected from different regions of Henan, Shandong and Hebei provinces were determined by mycelia growth inhibition method in order to confirm the sensitivity of F. graminearurn to the triazole fungicides tebuconazole. Sensitivity of ten sensitive strains to iprodione, thiram, chlorothalonil, difenoconazole and carbendazim were tested by the same method to make sure that cross resistance was existed or not between tebuconazole and other diverse active mechanism fungicides. The results showed that mycelial growth of F. graminearurn was affected by tebuconazole,with a mean EC50 of （0. 102 6 ±0. 045 4） μg/mL,a difference of 27. 875 times between the highest and the lowest ranging from 0. 007 2 to 0. 200 7μg/mL, which could be regarded as the baseline sensitivity of F. grarninearurn to tebuconazole because frequency distribution of the 120 strains was similar to Gaussian distribution pattern. Linear regression result showed no positive-correlated cross resistance between tebuconazole and other diverse active mechanism fungicides.