2009年我国部分麦区小麦白粉菌群体对三唑酮和嘧菌酯的敏感性测定

自1976年以来,三唑酮一直就是我国防治小麦白粉病的主要药剂.1991年首次在山东省发现抗性菌株,之后其他地区也相继有抗药性菌株的报道.本实验室从1995年就开始监测小麦白粉菌对三唑酮的抗药性,研究结果表明,平均抗性水平和抗性菌株的频率均总体呈上升趋势1-3].

Sensitivity of Blumeria graminis f.sp. tritici isolates to triadimefon and azoxystro-bin in 2009 in China

The isolates of Blumeria graminis f. sp. tritici were sampled and isolated from 7 provinces/cities, and the sensitivity of 110 isolates to triadimefon and 130 isolates to azoxystrobin were tested using seed treatment and detached leaf segment methods, respectively. The results showed that the mean EC⁵⁰ of the isolates to triadimefon was 118.24 mg·L_-1, and the mean resistance factor (Rf) was 56.58. The frequency of resistant isolates to triadimefon reached 99.09%. The high resistant isolates (Rf＞40) accounted for 49.09%, and the moderate resistant isolates (10＜Rf≤40) accounted for 47.27%, while only one sensitive isolate accounted for 0.91% was detected in Hubei Province . The base-line of B. graminis f. sp. tritici to azoxystrobin was 41.03 mg·L_-1. No significant cross-resistance was observed between triadimefon and azoxystrobin for B. graminis f. sp. tritici. These results will provide some references for the chemical control of wheat powdery mildew disease as well as the appropriate use of the fungicides.