抗性小菜蛾乙酰胆碱酯酶对有机磷及氨基甲酸酯不敏感性研究

STUDIES ON THE INSENSITIVITY OF ACETYLCHOLINESTERASE TO ORGANOPHOSPHATES AND CARBAMATES IN Plutella xylostella (L. )

福州地区田间小莱蛾Plutella xylostessa L.已对水胺硫磷、克百威、敌敌畏和三唑磷产生高抗,抗性倍数分别为23.52、28.41、16.06和23.43倍.抗性小菜蛾幼虫体内AchE的Km和Vmax值分别为敏感185和0.63倍.水胺硫磷、甲基异柳磷、克百威、敌敌畏对敏感小菜蛾AchE的Ki值分别为抗性的58.75、30.33、198. 87和36.32倍.作者认为AchE对有机磷及氨基甲酸敏感性的降低应是小菜蛾对该类杀虫剂产生抗性的重要机制.

The high resistance to isocarbophos, carbof uran, dichlophos and triazophos was found in the field strain of diamondback moth (DBM), Plutella xylostella (L. ) in Fuzhou, Fu-jian,and the resistant ratios varied from 23. 43 to 28. 41 folds. The kinetic parameters showed that the ratios of Km and Vmax of acetylcholinesterase (AchE) were 185 and 0. 63, respectively. In order to study the different sensitivity of AchE to pesticides between R and S strains, the bimolecular rate constant (Ki) were also measured. The Ki ratios of AchE to isocarbophos ,car-bofuran, dichlorpos and isofenphos methyl were 58. 75, 198. 87, 36. 32 and 30. 33, respectively. These results suggest that resistance to OPs and carbamates in resistant population of DBM is associated with the insensitivity of AchE.