对小地老虎具有杀虫毒力的苏云金芽孢杆菌菌株的分离及鉴定

Isolation and identification of Bacillus thuringiensis strains toxic to Agrotis ypsilon

从我国3种典型植被覆盖的6个地区的土壤样品分离得到了348株苏云金芽孢杆菌菌株,采用杀虫活性测定方法从中获得了32株对小地老虎具有高毒力的菌株。利用PCR-RFLP鉴定体系和SDS-PAGE蛋白分析法,研究了这32株苏云金芽孢杆菌的杀虫晶体蛋白基因类型和晶体蛋白表达情况,对小菜蛾、二化螟、棉铃虫的杀虫活性测定也证明了苏云金芽孢杆菌cry基因类型、表达蛋白及杀虫活性间的相关性。

Three hundred and eighty-four Bacillus thuringiensis isolates were isolated from 1626 soil samples collected from six areas covered by three typical vegetations. Thirty-two of them were shown to be highly toxic to Agrotis ypsilon. By using of the PCR-RFLP system and SDS-PAGE, the types of gene cry of the 32 B. thuringiensis isolates and the expression of insecticidal crystal proteins were analyzed. Furthermore, the toxicity of the 32 isolates to Helicoverpa armigera, Plutella xylostella and Chilo suppressalis were detected, respectively. The results revealed that the types of gene cry, insecticidal crystal proteins and their insecticidal activity were closely related.