Effects of herbicide tolerant transgenic soybeans on the diversity of soil nitrogen-fixing bacterial nifH genes in rhizosphere
Based on the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)and sequence analysis,two herbicide tolerant genetically modified soybeans (PAT,ALS) and the corresponding non-transgenic soybeans (PAT1,ALS1) and the local main non-transgenic soybean (Zhonghuang 13,CK)were selected to investigate the effects of herbicide tolerant transgenic soybean cultivation on nitrogen-fixing bacteria in rhizosphere under field experiment.The results showed that the community composition similarity of soil nitrogen-fixing bacteria between transgenic soybean (PAT,ALS) and the corresponding non-trans genic soybean (PAT1,ALS1) was approximately 60％.Compared to the corresponding non-transgenic soybeans (PAT1,ALS1),the diversity index (H) and evenness index (EH) of nitrogen-fixing bacterial nifH genes in rhizoshpere of herbicide tolerant genetically modified soybeans (PAT,ALS) both showed no significant difference (p ＞ 0.05).The sequencing and phylogenetic analysis indicated that nitrogen-fixing bacterial nifH genes in rhizoshpere of herbicide tolerant genetically modified soybeans (PAT,ALS) and the corresponding non-transgenic soybeans (PAT1,ALS1)mainly belonged to cyanobacteria,Proteobacteria and Firmicutes.Nitrogen-fixing microbial communities were significantly (p ＜ 0.05) influenced by the levels of the available phosphorus (AP) and nitrate nitrogen (NO3--N)when canonical correspondence analysis was used to identify relationship between nifH gene and soil physicochemical factors.This result indicated that herbicide tolerant genetically modified soybeans had no significant effects on the diversity of soil nitrogen-fixing bacterial nifH genes in rhizosphere.
国家科技期刊平台
NSTL
万方数据
维普
