摘要
Sichuan Basin situated in the west of China, the fourth-largest basin of China, is a special area with complicated geomorphology (mountain, pasture, gorge, virgin forest, highland, hurst, glacier, and plain), and contains a rich and unique biodiversity. In order to describe a systematic study ofcry gene resources fromBacillus thuringiensis (Bt) strains of different ecological regions in Sichuan Basin, a total of 791 Bt strains have been screened from 2650 soil samples. The analysis of thecry genes was based on the method of PCR-restriction fragment length polymorphism (PCR-RFLP).cry1, cry2, cry3, cry4/10, cry9, cry30, andcry40-type genes were found in this basin. Strains containingcry1 genes were the most abundant in our collection (66%), and twenty-one differentcry1-type gene combinations were found. Bt strains harboringcry2 genes were the second most abundant (39.5%), and the strains containingcry3, cry9, cry4/10, cry30, andcry40 genes were found in 2.5, 3.5, 4.2, 4.2, and < 1%, respectively. Furthermore, several novel haplotypescry genes were found, and the full-length sequences of three novelcry genes were obtained, which were designated ascry52Ba1, cry54Aa1, cry30Fa1 by theB. thuringiensis Pesticide Crystal Protein Nomenclature Committee, respectively. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) assay of 80 strains which did not produce any PCR products indicated that these strains may harbour potentially novel Cry proteins. All these researches mentioned above revealed that the diversity and particularity ofcry gene resources fromB. thuringiensis strains in Sichuan Basin.