中文摘要：

用Bourrain法、LaMontagne法、Zhou法、BBI.公司的试剂盒4种方法,比较研究了不同方法对内蒙古贝加尔针茅草原土壤基因组DNA的提取效果以及对后续分析的影响。用PCR-DGGE技术对贝加尔针茅草原土壤细菌群落结构进行分析,并对主要条带进行测序。结果表明：试剂盒法提取的DNA效果最好;贝加尔针茅草原土壤细菌主要由6个分支组成：变形菌门（Proteobacteria）中的α、δ、γ三个类群,放线菌门（Actinobacteria）,拟杆菌门（Bacteroidetes）,芽单胞菌门（Gemmatimonadetes）,酸杆菌门（Acidobacteria）和疣微菌门（Verrucomicrobia）。

英文摘要：

This study compared the bacterial diversity from soil in Stipa baicalensis steppe by polymerase chain reaction-denaturing gradient gel electrophoresis（PCR-DGGE） with four different DNA extraction methods.The DNArecover efficiency of the kit method was higher than others;further more the quality of DNA from kit is much better through analysis of the DGGE bands and sequencing the bands.The results suggested the microbial community in Stipa baicalensis steppe soil was mainly consisted of Actinobacteria,Proteobacteria,Bacteroidetes,Gemmatimonadetes,Acidobacteria,Verrucomicrobia.