中文摘要：

在温室条件下,利用PCR-DGGE技术和Q-PCR技术分析了两种转Cry1Ac基因抗虫棉及其亲本棉花在不同取样时期的根际真菌多样性和生物量的动态变化情况,以评价其生态安全.结果表明,转Bt基因棉与对照棉根际真菌优势条带组成在不同的取样时期极为相似,三者间差异条带多为不清晰的条带.转Bt棉SGK321根际真菌的生物量在苗期明显低于亲本对照,转Bt棉XP188根际真菌的生物量在花铃期较对照有轻微降低,其它时期两种转Bt棉根际真菌生物量没有显著降低,甚至还有增加的趋势.不过根际真菌群落结构的改变和生物量的差异不仅存在于转基因棉和其亲本对照棉之间,它同样存在于对照棉SHIYUAN321和JM20之间以及转基因棉SGK321和XP188之间.可见Bt并不是造成转基因棉和非转基因棉根际真菌群落结构差异、多样性改变和生物量减少的唯一诱因,品种的不同也对它们也有影响.

英文摘要：

The dynamics of rhizospheric fungal diversity and biomass at different sampling stages associated with two transgenic insect-resistant cottons expressing Cry1Ac protein and their control varieties were studied under greenhouse conditions, followed by PCR-denaturing gradient gel electrophoresis ( PCR-DGGE) and quantitative real-time polymerase chain reaction ( Q-PCR), in order to evaluate the ecological security of planting transgenic cotton expressing Cry1Ac protein. The results indicated that the fungal superior bands in rhizosphere of transgenic Bt cotton were similar with that of control cotton at four sampling stages, the more obvious difference in the blurred bands among transgenic Bt cotton, JM20 and SHIYUAN321 was detected. The rhizospheric fungal biomass of transgenic Bt cotton SGK321 was significantly lower than that of its parental control cotton at seedling stage, while the slight decrease in fungal biomass of transgenic Bt cotton XP188 was detected at boll forming stage, the ill-defined decrease, even growing tendency in two transgenic Bt cottons was detected at other stages. However, the difference of rhizospheric fungal community compositions and biomass was not only existed between transgenic cotton and its control, but also between SHIYUAN321 and JM20, and the same phenomenon was also detected between transgenic Bt cotton SGK321 and XP188. Hence, Bt protein is not the only incentive resulting in the difference in fungal community composition and diversity, the decrease in biomass between transgenic cotton and untransgenic cotton, different cotton varieties has an effect on them.