中文摘要：

基因工程是解决昆虫病原真菌致死慢、致死率低的有效途径,但在传代培养过程中,被转入的基因是否会丢失以及转基因工程株是否会像野生型菌株那样频繁地发生变异,引起产孢减少和毒力减退等生产性状的退化？针对这些问题,研究一株球孢白僵菌Beauveria bassiana转外源蝎毒基因工程菌株在继代培养过程中的的变异现象,发现工程株也和野生型菌种一样会发生菌落局变,但所插入的蝎毒基因并未丢失。与野生型出发菌株及其单孢分离株相比,工程株的角变率居高不下而产孢量及对松毛虫的毒力显著降低。然而,从该工程株筛选出的一株单孢分离株在继代培养中却比较稳定,产孢量及对松毛虫的毒力则远高于野生型出发菌株及其单孢分离株,是一株稳定的高产高毒优良菌株。

英文摘要：

Genetic engineering is an effective approach for solving the problems of slow speed of killing insect by entomopathogenic fungi.However,it remains problematic whether the inserted gene can be lost and whether variation and degeneration can occur in the transgenic strains during subculturing as those happen frequently to the wild-type strains.In the present paper,the variation of Bb13T-10-3,a AaIT-transgenic strain of Beauveria bassiana during subculturing was studied.The results revealed that sectorization of Bb13T-10-3 could occur,suggesting that it varied like its mother strain Bb13,but the inserted gene was not lost.As compared to the sectorization rate of Bb13 and one of its single spore isolate Bb13-S,that of Bb13T-10-3 remained high,while sporulation and virulence obviously declined on the pine caterpillar,Dendrolimus punctatus.However,Bb13T-10-3-S,one of the single spore isolates from Bb13T-10-3 was relatively stable,with sporulation and virulence against pine caterpillars being much higher than those of Bb13 and Bb13-S.