苹果轮纹病菌对苯醚甲环唑和氟硅唑的敏感性及其交互抗性

 为明确苹果轮纹病菌对苯醚甲环唑和氟硅唑的敏感性状况,本研究采用菌丝生长速率法检测了90个采自山东省各地区的苹果轮纹病菌对苯醚甲环唑和氟硅唑的敏感性。实验结果表明,苯醚甲环唑和氟硅唑对轮纹病菌的EC₅₀平均值分别为0.198 1±0.247 1 μg·mL^-1和0.117 4±0.121 8 μg·mL^-1。频次分布图显示,苹果轮纹病菌群体中出现了敏感性降低的亚群体。三唑类杀菌剂苯醚甲环唑、氟硅唑和戊唑醇之间具有交互抗性;而三唑类杀菌剂苯醚甲环唑、氟硅唑、戊唑醇与代森锰锌之间不存在交互抗性。田间试验结果表明,苯醚甲环唑和氟硅唑对高敏感性和低敏感性病菌引起的枝干轮纹病具有同等的防治效果。本研究结果为田间防控苹果轮纹病的杀菌剂合理轮换使用提供了理论依据。

Sensitivity of Botryosphaeria dothidea to difenoconazole and flusilazole and cross-resistance of different fungicides

The sensitivities of Botryosphaeria dothidea,the causal agent of apple ring rot,to difenoconazole and flusilazole fungicides were determined in 90 isolates collected from 17 cities of Shandong, China by measuring the mycelial growth on the fungicide-amended media. The means of the 50％ effective concentration values(EC₅₀) were 0.198 1±0.247 1 μg·mL^-1 and 0.117 4±0.121 8 μg·mL^-1,respectively. The results of frequency-analysis showed that low resistant subcolony had been discovered. There was cross-resistance among difenoconazoel,flusilazole and tebuconazole,but no cross-resistance between triazole fungicides and mancozeb. Difenoconazoel and flusilazole presented the same control effect to apple ring rot caused by high sensitivity and low sensitivity isolates through trunk artificial inoculation. The results provided a theoretical basis for using fungicides efficiently to prevent and control apple ring rot in the field.