梨黑星病菌对氟硅唑的敏感性及与不同杀菌剂之间的交互抗性

Sensitivity of Venturia nashicola to flusilazole and cross-resistance against diverse fungicides

采用孢子芽管长度法,测定了采自河北省不同地区的88个梨黑星病菌Venturia nashicola菌株对氟硅唑的敏感性,并测定了10个相对敏感菌株和5个相对抗性菌株对甲基硫菌灵、醚菌酯、福美双和苯醚甲环唑的敏感性。结果表明:不同地区黑星病菌对氟硅唑的敏感性存在一定差异,平均EC50值为(1.382 1±0.927 6)μg/mL;氟硅唑对未使用过麦角甾醇生物合成抑制剂(EBI)类杀菌剂的75个梨黑星病菌菌株的平均EC50值为(1.167 6±0.612 8)μg/mL,最大值是最小值的16.91倍,其敏感性分布频率呈连续性单峰曲线,且符合正态分布,故可作为敏感基线用于监测田间梨黑星病菌对氟硅唑的敏感性变化。不同菌株对5种药剂的敏感性相互关系分析表明,氟硅唑和苯醚甲环唑之间呈显著正相关,但与醚菌酯、甲基硫菌灵和福美双之间均不存在交互抗性关系。

The sensitivity of eighty-eight Venturia nashicola strains collected from four different regions in Hebei Province to flusilazole was tested by germ-tube length method,and the sensitivity of ten relatively sensitive strains and five relatively resistant strains to thiophanate-methyl,kresoxim-methyl,thiram and difenoconazole was also tested by the same method.The results showed that there were some differences among all the sensitivity with the mean EC50 value of（1.382 1±0.927 6） μg/mL.With a frequency of the sensitivity followed a normal distribution curve,the mean EC50 value of 75 strains collected from the field where EBIs fungicides had never been used was（1.167 6±0.612 8） μg/mL and the maximum was 16.91 times to the minimum,which could be regarded as the baseline sensitivity of V.nashicola to flusilazole for field resistance monitoring.The correlation between flusilazole and difenoconazole was significantly positive,but there was no cross-resistance with other three different fungicides.