五岳寨苏云金芽孢杆菌资源多样性分析及杀虫基因的鉴定

分离筛选高效广谱野生苏云金芽孢杆菌菌株并对五岳寨地区苏云金芽孢杆菌资源多态性进行分析。采用温度筛选法进行菌株分离筛选，光学显微镜下观测菌株的晶体形态，通过PCR-RFLP和SDS-PAGE法对这些菌株进行基因鉴定和蛋白分析，并进行生物活性测定。从土壤中分离得到72株Bt菌株，共包含13种cry基因，9种基因组合，另有8株未鉴定出基因型，SDS-PAGE蛋白分析发现这些菌株主要表达130、90、50 kDa蛋白；生物活性测定结果显示有20株对小菜蛾和棉铃虫具有高效毒力，另有4株对华北大黑鳃金龟有高效毒力，其中2株的校正死亡率可达80%。五岳寨地区苏云金芽孢杆菌资源丰富并具有良好的多态性。

Research on the Diversity and Identification of Bacillus thuringiensis Strains from Wuyuezhai Mountains

The aims were to screen the highly toxic and broad spectrum of wild-type Bacillus thuringiensis strain, and analyze the diversity of cry genes. 72 strains were isolated by temperature-antibiotic method. Several shapes of crystals protein were observed by optical microscope, by using of the PCR-RFLP system and SDS-PAGE, the types of cry gene of the 72 strains and the expression of insecticidal crystal proteins were analyzed. 72 strains were screened from soil, thirteen kinds of cry gene and nine gene combinations were found by using PCR-RFLP. The result of SDS-PAGE analysis showed that these strains expressed 130 kDa, 90 kDa and 50 kDa proteins in the first. Twenty strains of them were highly toxic to both Plutella xylostella and Helicoverpa armigera, four strains showed highly toxic to Holotrichia oblita larvae. All results showed the great diversity of Bt strains in Wuyuezhai Mountains.