小菜蛾对杀螟丹抗药性的生化遗传研究

Biochemical genetic mechanisms of resistance to cartap in diamondback moth, Plutella xylostella L.

采用室内选育的小菜蛾对杀螟丹的抗性品系和敏感品系，研究了各杂交世代小菜蛾多功能氧化酶（ＭＦＯ）、乙酰胆碱酯酶（ＡｃｈＥ）和羧酸酯酶（ＣａｒＥ）活性。结果表明：（１）抗性品系（抗性提高３５．５倍）多功能氧化酶环氧化活性比敏感品系高（１．８３倍），并随着杂交后代中对杀螟丹抗性水平的下降而降低；（２）抗药性品系和敏感品系的ＡｃｈＥ和ＣａｒＥ活性没有明显差异。因此，多功能氧化酶环氧化活性的提高是小菜蛾对杀螟丹抗性的一个重要机制，而ＡｃｈＥ和ＣａｒＥ活性与该抗性无关。

The activities of mixed function oxidase (MFO), acetylcholinesterase (AchE) and carboxylesterase (CarE) of cartap resistance in diamondback moth ( Plutella xylostella L.) were evaluated. The insects used for the study were laboratory reared resistant and susceptible strains. The results of study on activities of MFO, AchE and CarE showed that the epoxide activities of crude MFO extracts were stronger (1.83 fold) in the resistant strains (with resistance ratios 35.50 fold) than that in the susceptible ones. The decrease of cartap resistance in the offspring was accompanied by a corresponding drop in epoxide activities. There was no significant difference in the activities of AchE and CarE between these two strains. Therefore, the enhancement of aldrin epoxidase activity was an important resistance mechanism for cartap, but the resistance was not related to AchE and CarE.