艾氏剂环氧化酶及细胞色素P－450对小菜蛾抗药性发展的影响

本文对室内长期饲养的小菜蛾（Ｐｌｕｔｅｌｌａ　ｘｙｌｏｓｔｅｌｌａ　Ｌ．）敏感品系和田间采集的抗性种群体内的艾氏剂平氧化酶及细胞色素Ｐ－４５０进行了比较研究。结果证明，艾氏剂环氧化酶在感性和抗性小菜蛾间存在着量及质的差异。抗性种群的艾氏剂环氧化酶的Ｖｍａｘ和Ｋｍ值分别为感性品系的５．４％和６．５倍。抗性种群的细胞色素Ｐ－４５０的含量是感性品系的１．１—１．３倍。艾氏剂环氧化酶在量上及质上的差异及细胞色素Ｐ－４５０含量的提高是导致小菜蛾抗药性发生与发展的重要机制之一。而且质的差异较之量的差异可能起着更为重要的作用．

INFLUENCE OF ALDRIN EPOXIDATIONASE AND CYTOCHROMEP-450 ON THE DEVELOPMENT OF INSECTICIDE RESISTANCEIN DLAMON-DBACK MOTH, PLUTELLA XYLOSTELLA L

n investigation was made on the aldrin epoxidationase activity and cytochromeP-450 level in the larvae of the diamond-back moth Plutella xylostella which werecollected from different regions and distinguished as strains susceptible and resistantto DDVP and pyrethroids. The results of our further study indicated that there existed significant difference in quality and quantity of aldrin epoxidationase and cytochrome P-450 between the resistant and susceptible diamond-back moth larvae. TheKm and Vmax values of aldrin epoxidationase from the resistant strain were 6.5 and5.4 times higher when compared with that from the susceptible strain. Based on thisfinding, we presume that the difference of aldrin epoxidationase in quaility and quantitye as well as the increase in cytochrome P-450 level are important factors for thedevelopment of insecticide resistance in the diamondback moth larvae and the qualitative difference in the enzyme systems may be more important.