顶孢霉菌对小菜蛾的毒力及体内保护酶活力的影响

The toxicity of Acremonium hansfordii to Plutella xylostella and its effect on endogenous enzymes of protective system

采用浸渍法和酶活力测定方法研究了顶孢霉菌对小菜蛾的毒力及对小菜蛾体内蛋白质含量和保护酶活力的影响.结果表明:在接种后的第5d,顶孢霉菌对小菜蛾的致死中浓度(LC50)为5.32×106个.mL-1,其毒力回归方程为y=2.66+0.35x;顶孢霉菌侵染3龄小菜蛾后,处理组蛋白质含量降低,超氧化物歧化酶(SOD)、过氧化物酶(POD)及过氧化氢酶(CAT)3种保护酶活性下降,处理组前期,3种保护酶活性与对照差异不明显,但后期处理组酶活性明显低于对照.处理组由于顶孢霉菌的侵染,导致小菜蛾有机体丧失免疫能力,SOD、POD和CAT活性下降,并随着时间延长,保护酶活力下降愈明显.

By using dipping and determination of enzyme activity,the toxicity of Acremonium hansfordii to Plutella xylostella and its effect on the content of protein and enzymes of protective system were studied.The results indicated that after 5 days inoculation,the LC50 reached to 5.32×106 spore·mL-1,the toxicity regression equation was y=2.66＋0.35x.After infected by Acremonium hansfordii,the protein content of Plutella xylostella and the activities of SOD,POD and CAT were all decreased.At the beginning,the three protective enzymes in treatment and control were almost the same.But they were obviously lower than the control in later period.The Plutella xylostella lost its organism immunity caused by infecting with the Acremonium hansfordii.The activities of SOD,POD and CAT reduced obviously with the treated time growing.