赤拟谷盗的磷化氢敏感和抗性品系体内羧酸酯酶的活性比较

Comparison of carboxylesterase acitivity between the resistant and susceptible strains of Tribolium castaneum to phosphine

本文比较测定了赤拟谷盗Tribolium castaneum(Herbst)的磷化氢抗性(Rf=327)和敏感品系害虫的羧酸酯酶活性,研究了该害虫同一品系不同个体间羧酸酯酶的活性差异,比较了两品系害虫在系列磷化氢浓度下熏蒸24h和6.94×10-2mg/L磷化氢浓度下熏蒸不同时间的羧酸酯酶活性。主要结果为:未熏蒸的抗性害虫幼虫和蛹体内的羧酸酯酶活性分别高于敏感品系的1.37和1.16倍;敏感和抗性害虫同品系内不同个体间羧酸酯酶活性分布频率都存在明显差异,抗性害虫中酶活性大的个体数量占的比例较大;磷化氢浓度分别为0.69×10-2、2.78×10-2、5.56×10-2、8.33×10-2和11.11×10-2mg/L时都可导致敏感害虫羧酸酯酶的活性降低,但活性受抑制的程度不因浓度高低呈相应的增减。浓度分别为5.56×10-2、11.11×10-2、13.89×10-2、20.83×10-2和27.78×10-2mg/L的熏蒸中抗性害虫体内酶活性增加,且活性增高的程度与浓度增减也不呈对应变化。在6.94×10-2mg/L磷化氢浓度下熏蒸不同时间的结果中,敏感害虫的酶活性随时间延长而下降,抗性害虫的活性则随时间延长而增大。研究表明赤拟谷盗对磷化氢的抗性可能与羧酸酯酶的活性增加有关。

The specific activity of carboxlesterase from the resistant（with 327 resistance factor） and susceptible strain of Tribolium castaneum（Herbst） to phosphine was measured comparatively.Frequency distributing of the specific activity of the enzyme for both strains was analyzed further.The special activity of fumigated and unfumigated insects was also determined for the comparison,with different concentration of phosphine in 24 h and different exposure time at concentration of 6.94×10^-2 mg/L phosphine.The results showed the specific activity of carboxlesterase in larvae and pupae of resistant strain was 1.73 and 1.16 times higher than that of susceptible one for larvae and 1.16 times higher than that of susceptible strain,respectively.There was a significant difference in the frequency distribution of the specific enzyme activity between two strains in which the frequency of insect individuals with higher specific activity in resistant strain was more than that of susceptible insects.The specific enzyme activity from susceptible strain was decreased after 24 h fumigation at tested concentration of 0.69×10^-2,2.78×10^-2,5.56×10^-2,8.33×10^-2 and 11.11×10^-2 mg/L apart,and that from resistance was increased after the fumigation with concentration of 5.56×10^-2、11.11×10^-2、13.89×10^-2 、20.83×10^-2 and 27.78×10^-2 mg/L.The specific enzyme activity in susceptible strain was decreased and that of resistance strain was increased with the exposure time going on at the concentration 6.94×10^-2 mg/L of phosphine.It revealed that the resistance to phosphine might be related to the activity of carboxlesterase in red flour beetle.