苏云金芽孢杆菌科默尔亚种15A3株的cry基因分析及杀虫特性

Characterization of cry Gene and Broad Spectrum Against Lepidopteran of Bacillus thuringiensis subsp.colmeri 15A3

筛选的苏云金芽孢杆菌野生菌株 1 5A3经鉴定属血清H 2 1型科默尔亚种。用PCR及RFLP方法对其cry1类基因分析证明其含有cry1Aa,cry1Ac,cry1Ca,cry1D ,cry1I及cry2六种cry基因 ,其cry1A基因N末端 1 45kb片段与已发表的序列有差异。表达晶体蛋白质的分子量分别为 1 3 0 ,79,70 ,6 5 ,5 1和 45kD。对家蝇致畸实验证明其不含 β 外毒素。发酵液对棉铃虫 ,甜菜夜蛾 ,小菜蛾及美国白蛾均具较高的毒力。

Bacillus thuringiensis wild type strain 15A3 belongs to subspecies colmeri serotype H-21.RFLP and PCR analysis show that it contains six types of ICP genes:cry1Aa,cry1Ac,cry1Ca,cry1D,cry1I and cry.The sequence of the 1.45kb N-terminal fragment of cry1Aa differed from that of published.SDS-PAGE showed that the crystal consists of proteins with molecular weight about 130,79,70,65,51 and 45kD.Strain 15A3 didn't sysnthesize heat-stable β-exotoxins according to test of house fly aberration.The 1.2 tons fermentative production exhibited high toxicity against three lepidopteran pests:H.armigera,S.exigua and H.cunea. It was proved that wild type strain can produce a broad specturm of ICP.