抗联苯菊酯枸杞蚜虫羧酸酯酶活性及4种常用杀虫剂对酶的抑制作用

Activity of carboxylesterase and inhibition effect of four insecticides on Car E in bifenthrin-resistant population of Aphis sp.

采用玻璃管药膜法,测定了联苯菊酯对中国内蒙古地区枸杞蚜虫的毒力,同时研究了不同抗性水平枸杞蚜虫羧酸酯酶(Car E)的活性,比较了敏感种群Ⅰ和高抗性种群Ⅴ的K_m和V_(max)值,以及毒死蜱、三唑磷、灭多威及氧乐果4种常用杀虫剂对联苯菊酯不同抗性水平枸杞蚜虫Car E的抑制作用。结果表明:与实验室饲养的敏感种群Ⅰ(LC_(50)值为0.057 mg/L)相比,不同地区枸杞蚜虫对联苯菊酯均产生了一定程度的抗性,其中种群Ⅴ的LC_(50)值为4.344 mg/L,抗性倍数达76.2,已达到高抗性水平。随着对联苯菊酯抗性水平的提高,枸杞蚜虫Car E的比活力逐渐增大,高抗性种群Ⅴ的比活力[0.533μmol/(min·mg)]是敏感种群Ⅰ[0.287μmol/(min·mg)]的1.9倍。进一步比较敏感种群Ⅰ和高抗性种群Ⅴ的K_m和V_(max)值,发现K_m值几乎无变化,但高抗种群Ⅴ的V_(max)值是敏感种群Ⅰ的2.08倍。4种杀虫剂对不同抗性水平枸杞蚜虫Car E的抑制作用不同,但均随着试虫抗性水平的升高,抑制中浓度(I_(50))值增大。表明羧酸酯酶在枸杞蚜虫对联苯菊酯的抗性中具有重要作用。

The toxicity of bifenthrin to Aphis sp.was determined by the method of the residual film in glass tube.Carboxylesterase activity of Aphis sp.was measured.The Km and V（max） of carboxylesterase in populationⅠand populationⅤwas studied.And the inhibition effects of 4 insecticides（chlorpyrifos,triazophos,methomyl and omethoate）to Car E in different populations were determined.The results showed that Aphis sp.had resistance to bifenthrin in different levels compared with the sensitive populationⅠof Aphis sp..LC（50） of the sensitive populationⅠwas 0.057 mg/L,and it was 4.344 mg/L in the case of populationⅤ.The resistance of populationⅤto bifenthrin was 76.2-fold to that of the sensitive population,which could be classified as high level resistance.The activity of Car E increased with the increasing of resistance levels.There was no significant different in Km between sensitive populationⅠand high resistant populationⅤ.However,the V（max） of resistant populationⅤwas 2.08-fold compared with the sensitive populationⅠ.Inhibition effects of 4 insecticides to Car E of different populations were different,and I（50） increased with the increasing of resistance level to bifenthrin.Carboxylesterase plays an important role in the resistance of Aphis sp.to bifenthrin.