【摘要】 对本室筛选的高活性Ｂ．ｔ．野生株进行了ｃｒｙ 基因检测，Ｓｏｕｔｈｅｒｎ杂交证明ｃｒｙＩＡｃ和ｃｒｙ１Ｃ位于质粒上．利用接合转移和电穿孔转化等方法对这些菌株进行了遗传改良研究．结果表明：高效野生株７４０４、ＨＤ－１－Ｘ和９５１０ 不易获得并表达外源ｃｒｙ 基因，而高效野生株Ｂｔｉ． ｔ－１８９７ 的电转化频率较高，并获得以Ｂｔｉｔ－１８９７ 为受体，对甜菜夜蛾、棉铃虫、黏虫和淡色库蚊均有毒力，具有ｃｒｙＩＡｃ、ｃｒｙＩＣ、ｃｒｙＩＶ及ｃｙｔ多价基因的广谱工程菌株．更多还原

【Abstract】 Several wild type Bacillus thuringiensis strains, which are highly toxic against Lepidopteran or Dipteran larvae, were detected for their cry gene types using PCR technology. Based on Southern hybridization, cry IAc gene was located on the 45MD plasmid of strain 7404, and cry IC gene was located on the 50MD plasmid of strain 9510. Conjugation and electroporation were used to genetically improve these strains. It showed that the wild type strains 7404, HD 1 X and 9510 were not easy to accept foreign cry gene by conjugation and eletroporation. While Bti. t 1897, which was highly toxic to Dipteran lavare, could be transformed at high freqency with the plasmid carring cry gene. Transformants Bti t 1897 T1～T14 and TT13 were obtained, which contained multi cry genes and exhibited toxicity to several Lepidopteran and Dipteran larvae.更多还原