西花蓟马抗辛硫磷种群的抗性机制及交互抗性

为明确西花蓟马对辛硫磷的抗性风险,研究了西花蓟马抗辛硫磷种群对其他杀虫剂的交互抗性及其对辛硫磷的抗性机制.交互抗性测定结果表明,西花蓟马抗辛硫磷种群对辛硫磷与毒死蜱、高效氯氟氰菊酯和灭多威存在中等水平的交互抗性,对溴虫腈、吡虫啉、甲维盐和多杀菌素存在低水平交互抗性,对啶虫脒和阿维菌素不存在交互抗性.酶抑制剂与辛硫磷的增效剂测定结果表明,胡椒基丁醚(PBO)、三丁基三硫磷酸酯(DEF)和磷酸三苯酯(TPP)对西花蓟马抗辛硫磷种群(XK)、田间种群(BJ)和敏感种群(S)均起到了显著的增效作用(P＜0.05),马来酸二乙酯对西花蓟马抗辛硫磷种群和敏感种群增效作用均不显著,但对田间种群增效作用显著(P＜0.05).生化测定发现:除田间种群西花蓟马乙酰胆碱酯酶活性提高不显著外,西花蓟马抗辛硫磷种群和田间种群的细胞色素P450含量(2.79和1.48倍)、细胞色素b5含量(2.88和1.88倍)及O-脱甲基酶活性(2.60和1.68倍)、羧酸酯酶活性(2.02和1.61倍)和乙酰胆碱酯酶活性(3.10倍)均显著高于敏感种群(P＜0.05)；谷胱甘肽-S-转移酶酶活性也有一定程度提高(1.11和1.20倍),但不显著(P＞0.05).表明其体内解毒代谢酶和靶标酶活性提高是西花蓟马对辛硫磷产生抗性的重要原因.

Resistance mechanisms and cross-resistance of phoxim-resistant Frankliniella occidentalis Pergande population

To understand the resistance risks of Frankliniella occidentalis Pergande against phoxim,this paper studied the resistance mechanisms of phoxim-resistant F.occidentalis population against phoxim and the cross-resistance of the population against other insecticides.The phoxim-resistant population had medium level cross-resistance to chlorpyrifos,lambda-cyhalothrin,and methomyl,low level cross-resistance to chlorfenapyr,imidacloprid,emamectin-benzoate,and spinosad,but no cross-resistance to acetamiprid and abamectin.The synergists piperonyl butoxide(PBO),s,s,s-tributyl phosphorotrithioate(DEF),and triphenyl phosphate(TPP) had significant synergism(P<0.05) on the toxicity of phoxim to the resistant(XK),field(BJ),and susceptible(S) populations,while diethyl maleate(DEM) had no significant synergism to XK and S populations but had significant synergism to BJ population.As compared with S population,the XK and BJ populations had significantly increased activities of mixed-functional oxidases P450(2.79-fold and 1.48-fold),b5(2.88-fold and 1.88-fold),O-demethylase(2.60-fold and 1.68-fold),and carboxylesterase(2.02-fold and 1.61-fold,respectively),and XK population had a significantly increased acetylcholine esterase activity(3.10-fold).Both XK and BJ population had an increased activity of glutathione S-transferases(1.11-fold and 1.20-fold,respectively),but the increment was not significant.The increased detoxification enzymes activities in F.occidentalis could play an important role in the resistance of the plant against phoxim.