苏云金杆菌cry Ⅰ A(a)、cry Ⅰ A(b)和cry Ⅰ A(c)基因型的PCR分析鉴定

根据苏云金杆菌（Ｂａｃｉｌｕｓｔｈｕｒｉｎｇｉｅｎｓｉｓ）杀虫晶体蛋白基因的结构特点，合成了ｃｒｙⅠ基因５′端特异引物和３′端共同引物，利用ＰＣＲ扩增，使不同基因引物产生不同长度的扩增产物，通过扩增产物片段的分子量大小来确定菌株所含杀虫基因类型．本研究对福建农业大学生物技术中心分离和保存的２０个菌株进行了ｃｒｙⅠＡ（ａ～ｃ）基因类型的ＰＣＲ鉴定．结果表明：４个菌株含有ｃｒｙⅠＡ（ａ）、ｃｒｙⅠＡ（ｂ）和ｃｒｙⅠＡ（ｃ）基因，２个菌株含有ｃｒｙⅠＡ（ａ）和ｃｒｙⅠＡ（ｃ）基因，其余菌株不含所鉴定的基因类型．

PCR identification of cry ⅠA(a), cry ⅠA(b) and cry ⅠA(c) gene types of Bacillus thuringiensis strains

A rapid identification of gene types of Bacillus thuringiensis strains was established by using PCR. Based on the structural characteristics of insecticidal crystal protein genes harbored by Bt , general and specific primers were selected to identify the 3 different cry Ⅰ genes. Differentiation among 20 strains was made on the basis of the electrophorestic pattern of the PCR products. PCR amplification containing four primers was capable of distinguishing between the strains giving products of 724, 236 and 487 bp for the cry ⅠA(a), cry ⅠA(b), and cry ⅠA(c) genes respectively. Of 20 strains, it showed that 4 strains harbored three genes and 2 strains harbored two genes.