摘要： Zwittermicin A (ZwA)能够增加苏云金杆菌(Bacillus thuringienesis，Bt)Cry1Ac蛋白的杀虫活性。生物测定使用生长在人工饲料上的甜菜夜蛾幼虫。用 Cry1Ac蛋白单独处理甜菜夜蛾初孵幼虫，体重抑制活性明显，杀虫活性较低；单独用ZwA处理时无杀虫活性。当ZwA浓度为0.1 mg/mL、Cry1Ac浓度为1 mg/mL时，48 h校正死亡率达90%。对甜菜夜蛾5龄幼虫进行生物测定，当用25 μg ZwA和5 μg Cry1Ac分别饲喂试虫时，无杀虫活性；用25 μg ZwA和5 μg Cry1Ac同时饲喂试虫时，84 h试虫全部死亡。对甜菜夜蛾5龄幼虫中肠组织切片分析发现，口服25 μg ZwA和5 μg Cry1Ac的幼虫12 h，中肠变细小，中肠壁变厚，围食膜无法正常形成；3 h后中肠壁逐渐恢复正常，围食膜重新形成。

关键词: Zwittermicin A, Cry1Ac, 生物活性测定, 中肠, 围食膜

Abstract: Zwittermicin A(ZwA)enhanced the insecticidal activity ofBacillus thuringienesis(Bt)Cry1Ac protein.The mortality was 90% at 48 h after S.exigua larvae were treated with Cry1Ac in the presence of ZwA,which was higher than that without ZwA.All the 5th-instar larvae were dead at 84 h after fed with 5 g of Cry1Ac plus 25 g of ZwA(per larvae).Microscopical observation of dissected midgut showed that at 12 h post feeding with Cry1Ac and ZwA no PM were present in the treated larvae,in contrast to the presence of a fully formed PM in the midgut of control larvae.But after 36h,the midgut displayed normal and PM formed again.

Key words: Zwittermicin A, Cry1Ac, Bioassay, Midgut, Peritrophic membrane

中图分类号: 

• S476+.1