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以对有机磷杀虫剂敏感的品系(SS) 和抗性的品系(R2) 为试虫材料, 利用生测和生化分析两种方法研究了羧酸酯酶在棉铃虫对有机磷杀虫剂抗性形成中的作用。结果表明: TPP对久效磷、辛硫磷的增效比在R2品系中分别为2.76 和2.46倍, 在SS品系中分别为1.85 和1.48 倍; 两品系羧酸酯酶的Km 和Vm ax之间存在显著的差异, R2 和SS品系羧酸酯酶的米氏常数Km 、Vm ax分别为76.74 μm ol/L、56.29 nm ol/ (m in·m g) 和107.39 μm ol/L、44.40 nm ol/ (m in·m g); 两品系的羧酸酯酶对TPP、久效磷和辛硫磷的抑制反应也不同,三种化合物对SS品系的抑制中量I50分别为39.21,68.80 和0.25 μg/m L, 对R2 品系的I50分别为62.95, 91.05 和0.41 μg/m L。由此认为: 羧酸酯酶解毒代谢活性的增加是棉铃虫对有机磷杀虫剂产生抗性的机理之一。
The results showed that the carboxylesterase activity in the susceptible strain (R2) of organophosphate insecticide (SS) and resistant strain (R2) The role of resistance in the formation. The results showed that the synergistic ratio of TPP to monocrotophos and phoxim was 2.76 and 2.46 times respectively in R2 and 1.85 and 1.48 times respectively in SS; the Km and Vm ax of carboxylesterase The Km and Vm ax of carboxylesterase in R2 and SS strains were 76.74 μmol / L, 56.29 nmol / (m in · mg), 107.39 μmol / L and 44.40 nmol / (m in · mg). The inhibition of carboxylesterase (TPP), monocrotophos and phoxim in the two lines was also different. The inhibitory concentrations (I50) of the three compounds against SS were 39.21, 68.80 and 0.25 μg / m L, and the I50 of R2 strain were 62.95, 91.05 and 0.41 μg / m L, respectively. Therefore, it is thought that the increase of detoxification metabolic activity of carboxylesterase is one of the mechanisms that cotton bollworm is resistant to organophosphate insecticides.