黄瓜白粉病菌对苯醚菌酯敏感基线的建立及室内抗药性风险评价

Determination of sensitivity baseline of Sphaerotheca fuligine to ZJ0712 and assessment of Its laboratory resistant risk

采用叶碟保湿培养法测定了59株黄瓜白粉病菌对苯醚菌酯的敏感性,并建立了敏感基线。结果表明:苯醚菌酯对59个菌株的平均EC50为(0.0105±0.0028)μg/mL,其敏感性频率分布呈连续性单峰曲线,没有出现敏感性下降的抗药性亚群体。因此,该敏感基线可以作为监测田间病原菌对苯醚菌酯敏感性变化的参考。室内采用药剂驯化得到4株抗药性突变体,其抗性指数均高于150,且抗药性状能够稳定遗传。室内抗药性风险评价显示,4株抗药性突变体在致病力、竞争力上与亲本菌株相比无明显差异或优于亲本菌株。综合分析表明,黄瓜白粉病菌对苯醚菌酯具有较高的室内抗药性风险。因此,在该药的使用过程中应当采取相应的抗性治理措施。

The sensitivity of the 59 Sphaerothecafuligine strains to ZJ0712 was determined by the leaf discs assay. The results showed that the mean of EC50 values was （0. 010 5 ±0. 002 8）μg/mL. The sensitivity frequency of S. fuligine strains to ZJ0712 distributed as a unimodel curve, which showed there was no resistant subpopulation among these strains. Thus, it could be used as baseline-sensitivity of S. fuligine to ZJ0712 for field resistance monitoring. In laboratory, four ZJ0712-resistant mutants were obtained through fungicide adaptation. The resistance of all mutants was stable and the resistance factor was more than 150. In vitro, as compared to their parental strains, the pathogenicity and the competition of resistant mutants were no significantly difference or excelled them. The results suggested that ZJ0712 was a high risk fungicide in laboratory and appropriate precautions against resistance development should be taken.