转Bt基因玉米对根际土壤细菌遗传多样性的影响

连续两年在田间自然状态下，采用PCR-DGGE方法研究6个不同生育期种植转Bt基因玉米MON810对根际土壤细菌群落遗传多样性的影响。结果表明，2008年，同一生育期内转Bt基因玉米与非Bt基因玉米根际土壤细菌16S rDNA DGGE指纹图谱相似，细菌群落的遗传物质组成差异不显著，仅在抽丝期和乳熟期Bt玉米出现两条差异条带。2009年，苗期、拔节期、喇叭口期、抽雄期4个生育期两种玉米出现差异条带，抽丝期和乳熟期无差异条带。对DGGE图谱条带进行克隆测序，部分图谱中的条带所代表的DNA序列相同，最终得到51条DNA序列，共涉及主要细菌门类8个，典型差异条带分别属于芽单胞菌门（Gemmatimonadetes）、变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）。总体来看，与不同品种相比，不同生育期、不同年份间细菌群落差异更为显著，Bt蛋白的积累对根际细菌群落变化有一定影响。

Effects of Transgenic Bt Corn on Genetic Diversity of Bacteria in Rhizospheric Soil

Effects of transgenic Bt corn on bacteria genetic diversity in rhizospheric soil were studied by using PCR-DGGE within six different growth periods. The results showed that, in 2008, the 16s rDNA DGGE fingerprint of Bt maize was basically similar to non-Bt corn in one growth period and Bt corn had one different band in silking and milk stages respectively. In 2009, there were different bands in the first four growth periods and no different band in the last two. Cloning and sequencing of DGGE bands suggested that there were 51 DNA sequences belonged to 8 bacteria classes. Different bands belong to Gemmatimonadetes, Proteobacteria and Firmicutes respectively. On the whole, the differences among the Bt corn and non-Bt corn were not obvious relative to the effects of different growth stages and different year on rhizosphere bacteria diversity. The accumulate of protein made a bit of difference on the bacteria community of rhizospheric soil.