小菜蛾对阿维菌素的抗性风险评估及交互抗性的室内测定

Resistance Risk Assessment and Cross-Resistance of Plutella xylostella to Abamectin

在室内用阿维菌素对小菜蛾进行抗性选育,结果表明:小菜蛾对阿维菌素的抗性发展先慢后快,经过20代14次选育,与敏感种群相比,抗性指数为20.92倍。应用域性状分析法,小菜蛾对阿维菌素的抗性现实遗传力为0.1303,在致死率为50%～99%的选择压力下,预计小菜蛾对阿维菌素抗性增长10倍,需要2.4～15.9代。这表明小菜蛾对阿维菌素产生高水平抗性的风险很大。交互抗性测定结果表明,阿维菌素抗性小菜蛾种群对甲维盐具有明显的交互抗性,抗性指数为8.85倍;对多杀菌素、茚虫威、氟虫腈和溴虫腈类药剂无交互抗性或交互抗性不明显。

A laboratory selection was conducted for Plutella xylostella resistance to abamectin. The results showed that the resistance developed slowly at first and then quickly during the selection. After 14 times of selection during the 20 generations,P.xylostella exhibited 20.92-folds resistance to abamectin compared to the unselcetde parent strain. Estimation of realized heritability （h2） of resistance was studied based on the Tabashnik＇s method and the h2 for the entire selection experiment was 0.1303. It required 2.4 to 15.9 generations for P.xylostella to obtain 10 fold increase in resistance ratio under selective pressure of 50% to 99% mortality for each selective generation. These results suggested that P.xylostella might have the risk to develop high resistance to abamectin. The susceptibility of the resistant strain to other five insecticides was also tested. The results indicated that the resistant strain had an obvious cross-resistance to emamectin benzoate with a resistant ratio was 8.85 fold,but it had no or low cross-resistance to spinosad,indoxacarb,fiprronil and chlorfenapyr.