禾谷镰孢菌对苯醚甲环唑的敏感性基线及与其他杀菌剂敏感性的相关性分析

由禾谷镰孢菌引起的赤霉病是小麦上的重要病害，可严重影响小麦的产量并降低小麦的品质。苯醚甲环唑属于三唑类杀菌剂，是甾醇脱甲基化抑制剂，具有较高的抑菌活性。采用菌丝生长速率法测定了于2016—2017采集自河南省的107株禾谷镰孢菌对苯醚甲环唑的敏感性。结果表明:苯醚甲环唑对禾谷镰孢菌菌丝的生长具有较强的抑制效果，其有效抑制中浓度(EC₅₀)值范围为0.0128~0.6079 mg/L，符合正态分布，平均EC₅₀值为(0.2239 ± 0.1192) mg/L。因此，这些敏感性数据可以作为河南省禾谷镰孢菌对苯醚甲环唑的敏感性基线。通过对苯醚甲环唑与其他7种杀菌剂氟环唑、多菌灵、氰烯菌酯、氟唑菌酰羟胺、戊唑醇、丙硫菌唑及叶菌唑对20株禾谷镰孢菌的log₁₀ EC₅₀值之间的Spearman’s rho (ρ) 相关性分析发现:苯醚甲环唑与叶菌唑之间具有较低水平的相关性，与其他供试杀菌剂之间无相关性。本研究可为监测河南省禾谷镰孢菌对苯醚甲环唑的抗药性发展和防控小麦赤霉病合理用药提供依据。

Baseline sensitivity of Fusarium graminearum to difenoconazole and sensitivity correlation to other fungicides

Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most important destructive diseases of wheat, which leads to the decline in wheat yield and quality. Difenoconazole, a triazole fungicide, is an exemplary demethylation inhibitor of ergosterol biosynthesis with broad-spectrum and high-efficiency fungicidal activity. In this study, 107 isolates of Fusarium graminearum collected from Henan Province from 2016 to 2017 were assayed to determine their sensitivity to difenoconazole based on the mycelial growth inhibition by the fungicide. The results showed that difenoconazole had a high inhibitory effect on the mycelial growth of F. graminearum, and the EC₅₀ value was in range of 0.0128 to 0.6079 mg/L with a normal distribution, and the mean EC₅₀ value was (0.2239 ± 0.1192) mg/L (mean ± SD). Spearman’s rho (ρ) for the log₁₀ of the EC₅₀ values of 20 isolates of F. graminearum between difenoconazole and epoxiconazole, carbendazim, phenamacril, pydiflumetofen, tebuconazole, prothioconazole, and metconazole were analysed. The sensitivity correlation analysis showed that there was low level correlation between difenoconazole and metconazole, but no correlation with other tested fungicides.Therefore, these sensitivity data could be used as the baseline sensetivity of F. graminearum to difenoconazole in Henan Province and provide reference for the sensitivity monitoring to difenoconazole in the F. graminearum population and fungicide reasonable application.