土壤中对甲虫有活性苏云金芽胞杆菌的筛选

近几年来,甲虫已成为十字花科蔬菜的头号害虫。本文采集了湖北省各地区192份土壤样品,分离到苏云金芽胞杆菌(简称Bt)菌株74株,以甲虫代表——黄粉虫为靶标昆虫筛选了15株典型Bt,得到一株对甲虫有活性的Bt L1;生物测定该菌的半致死浓度(LC50)为221.20μg·g-1;聚丙烯酰胺凝胶电泳(SDS-PAGE)显示L1至少具有3个杀虫晶体蛋白;PCR扩增杀虫晶体蛋白基因,测序发现Bt L1中含有cry1Ac,cry1Aa,cry1Ia基因,推测Bt L1中对甲虫活性的杀虫晶体蛋白基因为cry1Ia。

Isolation of Soil Bacillus thuringiensis Against Coleoptera

In recent years,the Coleoptera pest has become the biggest problem for the cruciferous vegetables. In this study, the 192 soil samples were collected from different areas of Hubei province,and 74 Bacillus thuringiensis strains were isolated. B. thuringiensis L1 which had bipyramidal parasporal crystal,could kill Tenebrio molitor,a typical representative of the Coleoptera. The LC50was 221.20 μ·g-1. The SDS-PAGE displayed at lease three crystal proteins. The Bt stain L1 had three or more insecticidal crystal genes cry1Ac,cry1Aa and cry1Ia identified by the PCR technique. According to the literatures,the crystal protein which killed the Coleoptera was the Cry1Ia.