title: [Analysis of soil bacterial diversity by using the 16S rRNA gene library].
abstract: OBJECTIVE
  Soil microorganisms play an important role in the vegetable soil ecosystem. Through 16S rRNA gene cloning library technology to analysis the composition of bacteria community structure in the typical vegetable soil. To revealed the microbial diversity in the typical vegetable soil, and laid the foundation for the relationship between land-use changed and the ecological environment.
  
  
  METHODS
  Total microbial DNA was directly extracted from a typical vegetable soil of Beijing and Shandong province. The clone library of 16S ribosomal RNA genes was amplified using PCR with universal bacterial primer sets. The PCR products were then subcloned into pGEM-T vector. Each unique restriction fragment polymorphism pattern, created by using two restriction endonucleases (Hinf I and Hae III), was designated as an operational taxonomic unit (OTU). Amplified DNA was used for diversity analysis.
  
  
  RESULTS
  Constructed bacterial phylogenetic trees of the samples revealed the gamma-proteobacteria, beta-proteobacteria and alpha-proteobacteria groups were dominant in both clone libraries. Bacterial species composition from Beijing and Shandong province included 124 OTUs and 92 OTUs, respectively.
  
  
  CONCLUSIONS
  The dominant species of bacteria populations are proteobacteria in the typical vegetable soil of Beijing and Shandong areas. But bacterial diversity in the two typical vegetable soil samples was reduced. This phenomenon may be directly related to continuous cultivation for many years and plant a single vegetable species. At the same time, this phenomenon may also be an important reason to cause vegetable soil diseases widespread occurred and soil degradation.
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. liuweiqi10124@126.com
authors.forename: Weiqi
authors.initials: W
authors.lastname: Liu
authors.forename: Zhenchuan
authors.initials: Z
authors.lastname: Mao
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Yang
authors.forename: Bingyan
authors.initials: B
authors.lastname: Xie
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D015723:Gene Library; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S