转Bt基因玉米对根际土壤细菌群落结构的影响

Effects of transgenic Bt maize on bacterial community structure in rhizosphere soil

利用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术及扩增产物序列分析方法研究了转Bt基因玉米对根际土壤细菌群落结构及系统发育的影响。结果表明:转基因玉米与其非转基因亲本根际共有的土壤细菌分别隶属于变形菌门、疣微菌门、放线菌门、拟杆菌门、厚壁菌门、芽单胞菌门和酸杆菌门。其中,变形菌门为主要优势类群,占43.5%。不同生育时期转基因玉米与其非转基因亲本根际土壤细菌群落结构相似度高,差异条带少。土壤细菌16S rDNA DGGE图谱的数字化结果与土壤养分指标的典范对应分析显示,转基因玉米与其非转基因亲本根际土壤中全氮、全磷和速效氮的含量与土壤细菌群落结构密切相关。主成分分析的结果表明,转基因玉米与非转基因亲本根际土壤速效养分和细菌群落组成相似性高。综上所述,种植转Bt基因玉米1年对玉米根际土壤细菌群落结构无明显影响。

Polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE） and sequence analysis were employed to assess the effects of transgenic Bt maize on the bacterial com- munity structure and phylogeny in rhizosphere soil. In the rhizosphere soils of transgenic maize and its non-transgenic parents, most sequences were characterized by the members of Proteobacteria, Verrucomicrobia, Actinobacteria, Bacteroidetes, Finnicutes, Gemmatimonadetes, and Acidobacteria, among which, Proteobacteria was the dominant group, accounting for 43.5 % of the total. The bacterial community structure in the rhizosphere soils of transgenic maize and its nontransgenic parents at different growth stages was highly similar, and had few different bands. Canonical correspondence analysis of the DGGE fingerprints and nutrient contents in rhizosphere soils of transgenic Bt maize and its non-transgenic parents revealed that the bacterial community composition was strongly correlated with soil total nitrogen, total phosphorus, and available nitrogen contents. Principal component analysis showed that the available nutrient contents and bacteria community structure in rhizosphere soils of transgenic Bt maize and its non-transgenic parents were very similar. In sum, there was no evident difference in the bacterial community structure in the rhizosphere soils of transgenic Bt maize planted for one year and of non-transgenic maize.