小菜蛾对辛硫磷的抗性选育及其乙酰胆碱酯酶和羧酸酯酶活力变化

Selection of Plutella xylostella with Resistance to Phoxim and Its Changes in Activity of Acetylcholinesterase and Carboxylesterase

在室内模拟田间药剂的选择压力,用辛硫磷对小菜蛾(Plutella xylostella)逐代处理,以选育其抗性种群,并测定乙酰胆碱酯酶(acetylcholinesterase,AChE)和羧酸酯酶(carboxylesterase,CarE)的活性变化。选育至12代,对辛硫磷抗性增长到4.524倍。生化分析表明,抗性品系AChE和CarE活性均显著高于敏感品系。在抗性选育过程中,小菜蛾AChE酶活性增长迅速,其比活力由F0的0.035μmol/L.mg.min上升为F12的0.209μmol/L.mg.min;小菜蛾不同选育世代CarE酶活性差异显著,F12比活力增长到F0的12.944倍。

The selection of Plutella xylostella with resistance to Phoxim and its changes in the activity of acetylcholinesterase（AChE） and carboxylesterase（CarE） were carried out and observed in the laboratory.The susceptible population of P.xylostella was treated with Phoxim imitating field chemicals selection pressure in order to breed its resistance.The results showed that the resistance of P.xylostella to Phoxim had reached to 4.524-fold after 12 generations＇treatment.The biochemical assay showed that the activities of AChE and CarE in resistant strain were significantly higher than those in susceptible strain.During the selection process,the AChE activity increased quickly which rose from 0.035 μmol/L·mg·min（F0） to 0.209 μmol/L·mg·min（F12）.The activity of CarE was significantly different in different selection generations,the CarE activity in F12 was 12.944-fold as that in F0.