转Bt基因玉米种植对土壤细菌数量及多样性的影响

Effects of Transgenic Bt Maize on Populations and Diversity of Soil Bacteria

利用三室根箱装置获得玉米生长室土壤(SⅠ)、根际土(SⅡ)、非根际土(SⅢ)3个不同根区土壤,采用传统平板计数培养与变性梯度凝胶电泳(DGGE)技术相结合的方法,研究了转基因玉米B t11及其非转基因亲本在播种后40、50、60 d各根区土壤细菌数量及多样性的变化。结果表明,转B t基因玉米播种后50、60 d SⅠ根区土壤可培养细菌数量显著低于非转基因亲本,播种后40、50 d SⅡ根区土壤可培养细菌数量较亲本玉米显著增加,而在其他时期和根区与亲本玉米之间均无显著差异。DGGE图谱显示,3个采样时期各根区DGGE图谱条带数、土壤细菌多样性指数和均匀度指数均无显著差异(P>0.05)。

In this study,the three-compartment rhizobox method was used to collect soil samples from three different root zones of a maize plant,i.e.growth room（SⅠ）,rhizosphere（SⅡ）and non-rhizosphere（SⅢ） and the traditional plate count method and DGGE were applied to investigate changes in population and diversity of soil bacteria at D40,D50 and D60 after sowing of transgenic Bt maize and its parental maize.Results show that cultivation of transgenic Bt maize significantly reduced the population of soil cultivable bacteria in Zone SⅠ at D50 and D60,but increased the population in Zone SⅡat D40 and D50,and showed no significant impact in the other zone.DGGE fingerprints indicated no significant difference between soil samples taken at different dates in DGGE bands,diversity index and homogeneous degree index of the bacteria（P0.05）.