小麦白粉病菌对喹氧灵和苯菌酮的敏感基线及药剂的生物活性

采用离体叶段法,分别测定了从河北、河南、湖北、陕西和四川5省分离的53个小麦白粉病菌单孢菌株对苯菌酮和喹氧灵的敏感性,并分析了白粉病菌对三唑酮和苯菌酮以及喹氧灵之间的 交互抗性。结果表明:小麦白粉病菌群体对苯菌酮和喹氧灵的平均EC50值分别为(0.001 9±0.000 6) 和(0.013 1±0.002 0) mg/L,苯菌酮比喹氧灵具有更高的抑菌活性;小麦白粉病菌对三唑酮和苯菌酮与喹氧灵之间均不存在交互抗性(R2值分别为0.102 6和0.491 9);室内盆栽试验结果显示:接种前1 d和接种后1d施药,苯菌酮和喹氧灵对小麦白粉病的保护与治疗作用防效分别为92.21%、84.25%和82.43%、70.25%,表明这2种药剂不仅具有优异的保护作用,同时还具有较好的治疗作用。

Baseline sensitivity of Blumeria graminis f.sp.tritic to metrafenone, quinoxyfen and bioactivitives of these fungicides

The sensitivity of 53 Blumeria graminis f.sp.tritic(Bgt) strains to metrafenone and quinoxyfen were determined by leaf segment assay.The results showed that the mean EC₅₀ values is (0.001 9±0.0006) mg/L for metrafenone and (0.013 1±0.002) mg/L for quioxyfen;The sensitivity of Bgt to metrafenone was significantly lower than that of quinoxyfen,suggesting metrafenone has higher intrinsic activity on Bgt;Tradimefon showed no cross-resistance with metrafenone and quinoxyfen(R²=0.102 6,0.491 9,respectively).The curative and preventive activities of the two fungicides on Bgt in wheat were evaluated.With metrafenone and quinoxyfen fungicides treatments 1 days after inoculation and 1 days before inoculation,the efficacy of preventive and curative efficacy of the two fungicides were 92.21% and 84.25%,82.43% and 70.25%,respectively.Suggesting both fungicides had good curative and preventive properties.