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生态学杂志 ›› 2011, Vol. 30 ›› Issue (04): 790-797.

• 研究报告 • 上一篇    下一篇

呼伦贝尔草原土壤固氮微生物nifH基因多样性与群落结构

文都日乐1,2,李刚1,杨殿林1**,张静妮1,易津2   

  1. 1农业部环境保护科研监测所, 天津 300191;2内蒙古农业大学农学院, 呼和浩特 010018
  • 出版日期:2011-04-08 发布日期:2011-04-08

nifH gene diversity and community structure of soil nitrogen-fixing bacteria in Hulunbeier grassland, Inner Mongolia.

WENDU Ri-le1,2, LI Gang1, YANG Dian-lin1**, ZHANG Jing-ni1, YI Jin2   

  1. 1Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China| 2Agricultural College, Inner Mongolia Agricultural University, Hohhot 010018, China
  • Online:2011-04-08 Published:2011-04-08

摘要: 采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术及扩增产物序列分析方法比较研究了呼伦贝尔5种草地类型(线叶菊草原、贝加尔针茅草原、羊草草原、大针茅草原、克氏针茅草原)土壤固氮微生物nifH基因多样性及群落结构特征。结果表明,不同草地类型间土壤固氮微生物群落组成差异显著,羊草草原和大针茅草原相似性较高,相似度为67%,而其他3个草地类型间相似性较低,相似度均低于60%。羊草草原土壤nifH基因多样性最高,其次是克氏针茅草原、大针茅草原和贝加尔针茅草原,线叶菊草原最低。系统发育分析结果表明,呼伦贝尔草原土壤固氮微生物大部分属于变形菌门的α-变形菌纲,分别隶属于慢生根瘤菌属、中慢生根瘤菌属、红假单胞菌属、固氮螺菌属。5种草地类型中,克氏针茅草原土壤中联合固氮菌和自生固氮菌居多,而其他4个草地类型均以共生固氮菌为优势生态类型。

Abstract: Polymerase chain reaction-denaturing gradient gel electrophoresis and sequence analysis were adopted to assess the nifH gene diversity and community structure of soil nitrogen-fixing bacteria in five types of grassland (Filifolium sibiricum steppe, Stipa baicalensis steppe, Leymus chinensis steppe, S. grandis steppe, and S. kryrowi steppe) in Hulunbeier. The nifH gene diversity of nitrogen-fixing bacteria was the highest in L. chinensis steppe, followed by in S. kryrowi, S. grandis, S. baicalensis, and F. sibiricum steppes. The community composition of nitrogen-fixing bacteria differed significantly with grassland type. In L. chinensis steppe, the community composition of nitrogen-fixing bacteria had high similarity with that in S. grandis steppe, but the similarity among other three grassland types was lower than 60%. Phylogenetic analysis showed that most nitrogen-fixing bacteria were  Alpha-proteobacteria of Proteobacteria, belonging to Bradyrhizobium, Mesorhizobium, Rhodopseudomonas, and Azospirillum, respectively. In the 5 grassland types, free-living nitrogen-fixing bacteria and associative nitrogen-fixer were the major ecotypes in S. kryrowi steppe, while symbiotic nitrogen-fixer was the dominant ecotype in other four grassland types.

Key words: Cotton, Compound population, Cropping pattern, LAI, Leaf area duration