甜菜夜蛾对三种拟除虫菊酯类杀虫剂的抗性遗传力及风险评估

Realized resistance heritability and resistance risk of Spodoptera exigua to cyhalothrin,fenvalerate and alpha-cypermethrin.

在室内抗性选育的基础上，应用数量遗传学中的域性状分析法，分别研究了甜菜夜蛾（Spodoptera exigua）对三氟氯氰菊酯、氰戊菊酯和顺式氯氰菊酯3种拟除虫菊酯类杀虫剂的抗性现实遗传力（h^2）。并对3种药剂在不同杀死率下的抗性发展速率进行了预测．结果表明，用三氟氯氰菊酯、氰戊菊酯、顺式氯氰菊酯分别连续汰选12、10和10代后，甜菜夜蛾对3种药剂的抗性分别提高了18．1、27．6和45．4倍。抗性现实遗传力分别为0．2567、0．3571和0．4239．假设遗传力为实验室汰选估算值的一半、药剂杀死率为50％～90％、预计抗性增长10倍时，三氟氯氰菊酯需要约9～20代，氰戊菊酯需要约6～14代，顺式氯氰菊酯需要约5～12代．甜菜夜蛾对以上3种拟除虫菊酯类杀虫剂均存在抗性风险．相比之下，顺式氯氰菊酯和氰戊菊酯的抗性风险大于三氟氯氰菊酯．

In this paper, Spodoptera exigua from Fuzhou of Fujian Province was continuously selected and bred to test its resistance to cyhalothrin, fenvalerate and alpha.cypermethrin, and to evaluate its realized resistance heritability （ h^2） and resistance risk. The results showed that after 12, 10, and 10 generations, the resistance of S. exigua to cyhalothrin, fenvalerate and alpha-cypermethrin was increased by 18.1-, 27.6-, and 45.4-fold, and the realized resistance heritability was 0. 2567, 0. 3571 and 0. 4239, respectively. Assuming that the h2 of field S. exigua population was half of these values, it required 9 - 20 generations for cyhalothrin, 6 - 14 generations for fenvalerate, and 5 -- 12 generations for alpha-cypermethrin to obtain 10-fold increase in resistance under selective pressure of 50% -90% mortality for each selective generation. Of the three pyrethroids, the resistance risk to cyhalothrin was smaller than that to fenvalerate and alpha-cypermethrin,