中华稻蝗两地理种群酯酶特性的比较研究

对采自江苏徐州和山西临猗两个种群中华稻蝗进行了马拉硫磷敏感性的生物测定，同时对两个种群的酯酶特性进行了比较研究。生物测定结果表明，徐州种群的LD₅₀值（13.00 μg/g虫重）是临猗种群（4.64 μg/g虫重）的2.8倍；用对氧磷、马拉氧磷、西维因及毒扁豆碱等四种抑制剂对该两个种群的酯酶的体外抑制研究表明，两个种群所含酯酶大都为B型酯酶；酯酶动力学研究结果表明，徐州种群动力学参数米氏常数（K_m值）和最大反应速度（V_max值）均较临猗种群为高；用α-乙酸萘酯（α-NA）、α-丁酸萘酯（α-NB）和β-乙酸萘酯（β-NA）三种底物测定酯酶活性，在雌性稻蝗中，徐州种群比临猗种群分别高2.02、1.58和1.28倍，雄性中则分别高2.71、1.67和1.33倍；对两个种群酯酶活性频率分布进行比较，徐州种群中酯酶活性高的个体数远大于临猗种群。我们推测徐州种群酯酶的生化特性可能不同于临猗种群，这可能与地理分布、生态环境和食物条件不同有关，杀虫剂选择压力不同可能也起一定的作用。

Characterization and comparison of general esterases from two field populations of the grasshopper Oxya chinensis (Thunberg) (Orthoptera:Acridoidea)

Malathion susceptibility in the two populations of the grasshopper Oxya chinensis, collected from Linyi of Shanxi Province and Xuzhou of Jiangsu Province, China, was determined. General esterases from the two populations were characterized and compared. LD50 of the Xuzhou population (13.00(u)g/g body weight ) was 2.80-fold higher than that of the Linyi population (4.64 (u)g/g body weight). Inhibition studies of general esterases using four inhibitors, including paraoxon, malaoxon, eserine, and carbaryl, indicated that most general esterases in the two populations were B-type. Kinetic studies showed that the Michaelis-menten constant (Km) and the maximal velocity (Vmax)of general esterases from the Xuzhou population were higher than that from the Linyi population, using α- naphthyl acetate (α-NA), α-naphthyl butyrate (α-NB), β-naphthly acetate (β-NA) as substrates. The esterase activities in females of the Xuzhou population were 2.02, 1.58, and 1.28-fold higher than those of the Linyi population, usingα-NA, α-NB andβ-NA as substrates, respectively, and in males they were 2.71, 1.67, and 1.33-fold higher in the Xuzhou population than in the Linyi population. The spectrum of esterase activities showed that O. Chinensis individuals with high esterase activities were more in the Xuzhou population may be biochemically different from those in the Linyi population, and it might be attributed to the different geographic distributions, ecological environment and nutrition resources in on the two populations of O.chinensis.