长期施药果园中的苹果轮纹病菌对戊唑醇和甲基硫菌灵的敏感性

Susceptibility of Botryosphaeria dothidea to tebuconazole and thiophanate-methyl

为了监测果园中苹果轮纹病菌对戊唑醇和甲基硫菌灵敏感水平的变化,采用菌丝生长速率法测定了采集自山东烟台地区和北京市昌平区,有较长施药史苹果园中的苹果轮纹病菌对戊唑醇和甲基硫菌灵的敏感性。结果表明：戊唑醇对连续施用戊唑醇5年、每年施药1-2次的果园中苹果轮纹病菌的EC50为0.017 4-0.114 3μg/mL,即该类果园中苹果轮纹病菌对此药的敏感性仍然保持在较高水平,与野生菌株的敏感性非常接近,没有出现敏感性分化的抗药亚群体;甲基硫菌灵对连续施用甲基硫菌灵10年、每年施药2次的果园中苹果轮纹病菌的EC（50）为0.846 4-4.677 4μg/mL,果园中苹果轮纹病菌与野生菌株相比EC50平均值约上升3.15倍,最低值和最高值分别是已报道敏感性基线的1.19倍和6.59倍,没有出现敏感性发生显著分化的抗药性亚群体。

In order to monitor the susceptibility of Botryosphaeria dothideato tebuconazole and thiophanate-methyl in orchards with long history of using these two fungicides,the susceptibility of B.dothidea isolates collected from represented orchards to these two fungicides was determined based on mycelium growth rate.The results showed that the EC50 values of tebuconazole against 69 isolates collected from Yantai,Shandong Province with application of tebuconazole for 1-2 times each year for 5 years ranged from0.017 4 to 0.114 3μg/mL with no appeared resistant sub-populations.The EC50 values of thiophanate-methyl against 34 isolates collected from Changping District,Beijing with application of thiophanate-methyl for 2 times each year for 10 years ranged from0.846 4to 4.677 4μg/mL with no appeared resistant sub-populations.The maximum and minimum values were 1.19 and6.59 times of the reported susceptible baseline,respectively.