苦参碱对小菜蛾幼虫毒力测定及其对害虫体内2种酶活性的影响

Bioassay of Matrine and Its Effect on Two Enzyme Activities of Plutella xylostella Larvae

采用生物测定和酶活力测定方法,研究苦参碱对小菜蛾Plutella xylostella L.的胃毒活性及其对幼虫体内谷胱甘肽-S-转移酶、乙酰胆碱酯酶活性的影响。试验结果表明:苦参碱对小菜蛾幼虫具有一定的胃毒作用。2 mg/mL苦参碱处理叶片饲喂小菜蛾幼虫12 h校正死亡率为37.93%,72 h后小菜蛾幼虫的校正死亡率为95.83%。不同质量浓度苦参碱处理小菜蛾幼虫后,幼虫体内的谷胱甘肽-S-转移酶(GSTs)和乙酰胆碱酯酶(AChE)活力与对照相比均产生波动。经125×10-3mg/mL苦参碱处理4 h,小菜蛾体内GSTs活力最高,为1 610.72 U/(mg.min)。经125×10-3mg/mL苦参碱处理16 h,小菜蛾体内的AChE酶活力最高,为10.63 U/(mg.min)。各处理24 h,小菜蛾体内GSTs活力和AChE酶活力均有明显降低。说明苦参碱对小菜蛾幼虫体内谷胱甘肽-S-转移酶活力和乙酰胆碱酯酶活力有一定的影响。

Stomach toxicity of matrine to 3rd larvae of Plutella xylostella and its effects on activities of glutathione-S-transferase （GSTs）and acetylesterase （ACHE） were tested with bioassay and emzyme activity determination. The results showed that matrine had the stomach poisoning action on the Plutella xylostella larvae. At the concentration of 2mg/mL, the corrected mortality of the larvae was 37.93% at 12h after matrine application, while the corrected mortality of the larvae was 95.83% at 72 h. The GSTs and AChE activities of Plutella xylostella larvae changed for different dosages of matrine with the control. At the dosage of 125X10 amg/mLofmatrine,thehighest GSTs activity was1610. 72 Umg 1 min-1 at 4h, while the highest AChE activities was 10.63 U mg -1 min-1 at 16h with the dosage of 125 × 10 -3mg/mL of matrine. While the GSTs and AChE activities decreased at significantly 24 h. These results suggested matrine could influence GSTs and AChE activities of Plutella xylostella larvae.