【摘要】 采集全中国 2 7个省、自治区及 4个直辖市昆虫孳生地粉尘、土壤等样品 1 0 80份 ,在其中的40 6份中分离到苏云金芽孢杆菌 965株。镜检可观察到大菱形、小菱形、方形、长方形、圆形、椭圆形、镶嵌形和不规则形等 8种主要形态的伴孢晶体 ;采用cryⅠ、cryⅡ、cryⅢ、cryⅣ和cryⅤ基因的通用引物对 2 2 1株Bt分离株进行的PCR检测结果表明 :各类基因的含量依次为cryⅠ >cryⅡ >cryⅤ>cryⅢ基因 ,分别占被检菌株的 75 6%、 67 9%、 58 4%和 1 4 5% ,没有检测到cryⅣ基因 ,共得到1 0种基因组合类型。对其中含有cryⅠ基因的菌株分别以cryIAc、cryIC和cryIE基因的特异性引物进行PCR检测 ,得到 2 0株同时含有cryIAc、cryIC、cryⅡ和cryⅤ优良基因组合的Bt分离株 ,其中菌株Bt 1 5A3对棉铃虫、甜菜夜蛾及小菜蛾均表现出高毒力 ,具有生产开发潜力。更多还原

【Abstract】 samples were collected especially from pest habitats of dust,soil,et al from 27 provinces,municipalities and 4 directed cities all over China.From 406 samples of the collection 965 Bacillus thuringiensis strains were isolated.Eight mainly parasporal crystal shapes can be visualized by microscopic observation.221 Bt isolates were identified by the PCR method with general primers of cryⅠ,cryⅡ,cryⅢ,cryⅣ and cryⅤ genes,the result is that cryⅠ>cryⅡ>cryⅤ>cryⅢ gene,they were found in 75 6%,67 9%,58 4% and14 5% of the strains respectively,no cryⅠ Ⅴ gene was found,10cry gene combination types were concluded.The Bt isolates which contained cryⅠ genes were further characterized by additional PCR detection with specific primers of the cryⅠAc,cryⅠC and cryⅠE genes.20 Bt isolates which contained cryⅠAc,cryⅠC,cryⅡ and cryⅤ genes were found,among them the strain Bt\|15A3 is high toxic to Heliothis armigera,Spodoptera exigua and Plutella xylostella,and has potential developing and applying value.更多还原