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冰川冻土 ›› 2013, Vol. 35 ›› Issue (1): 208-216.doi: 10.7522/j.issn.1000-0240.2013.0025

• 寒区旱区生物学 • 上一篇    下一篇

祁连山高寒草原碱性土壤固氮微生物数量及固氮基因(nifH)群落结构研究

康文龙1, 台喜生2, 李师翁1, 董康1, 刘光琇2, 张威2   

  1. 1. 兰州交通大学 化学与生物工程学院, 甘肃 兰州 730070;
    2. 中国科学院 寒区旱区环境与工程研究所 沙漠与沙漠化重点实验室, 甘肃 兰州 730000
  • 收稿日期:2012-09-22 修回日期:2012-12-03 出版日期:2013-02-25 发布日期:2013-07-22
  • 通讯作者: 李师翁,E-mail:lishweng@mail.lzjtu.cn E-mail:lishweng@mail.lzjtu.cn
  • 作者简介:康文龙(1988-),男,甘肃天水人,2010年毕业于兰州交通大学,现为兰州交通大学在读硕士研究生,主要从事环境微生物研究.
  • 基金资助:

    中国科学院重点部署项目(KZZD-EW-04-05); 国家自然科学基金项目(31070357; 91025002; 31100365)资助

Research on the Number of Nitrogen-Fixing Microorganism and Community Structure of Nitrogen-Fixing (nifH) Genes in the Alkali Soils of Alpine Steppe in the Qilian Mountains

KANG Wen-long1, TAI Xi-sheng2, LI Shi-weng1, DONG Kang1, LIU Guang-xiu2, ZHANG Wei2   

  1. 1. School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou Gansu 730070, China;
    2. Key laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou Gansu 730000, China
  • Received:2012-09-22 Revised:2012-12-03 Online:2013-02-25 Published:2013-07-22

摘要:

对祁连山高寒草原碱性土壤可培养固氮菌数量、 固氮基因(nifH)群落结构及其理化性质进行了研究. 结果表明: 固氮菌数量在土层0~40 cm处于3.6×105~0.21×105CFUs·g-1之间, 除了海拔3 001 m的土样AQ4外, 其他3个土样固氮菌数量随着土壤深度的加深而减小. 固氮菌数量与地下生物量呈显著正相关性, 与有机碳、 可溶有机氮、 速效磷和速效钾呈正相关性, 而与pH值和全盐呈负相关性. 通过基因测序得到的37个固氮基因nifH克隆中, 蓝藻门占41%, 变形菌门占8%, 厚壁菌门占14%, 未知菌株占37%; 蓝藻门在除了AQ4外的土样中普遍存在, 并且是AQ1的优势固氮菌群. 此外, 还发现了4个新的nifH基因, 分别是AQ1-12(KC412109)、 AQ4-3(KC412133)、 AQ4-4(KC412133)、 AQ4-5(KC412133), 其中后三者是土样AQ4的优势种群.

关键词: 祁连山高寒草原, 碱性土壤, 固氮微生物, 固氮基因, 群落结构

Abstract:

The physicochemical characteristics, the number of culturable nitrogen-fixing bacteria and the community structure of nitrogen-fixing (nifH) genes in the alkali soils of alpine steppe in the Qilian Mountains are investigated in the present study. It is found that the number of culturable nitrogen-fixing bacteria is between 3.6×105~0.21×105 CFUs5g-1 within the depth of 0-40 cm. The number of nitrogen-fixing bacteria decreases with soil depth in three soil samples, except one sample (AQ4) at the altitude of 3 001 m.The number of nitrogen-fixing bacteria has a significant positive correlation with the underground biomass, and positive correlations with organic carbon, soluble organic nitrogen, rapidly available phosphorus and rapidly available potassium. However, it has negative correlations with soil pH value and total salt. Gene sequencing shows that in a community structure of 37 nitrogen-fixing (nifH) genes there are Cyanobacteria genes (41%), Proteobacteria genes (8%), Firmicutes genes (14%) and unknown bacterium genes (37%). Cyanobacteria genes exist in all soil samples, except for the sample AQ4, and are dominate nitrogen-fixing (nifH) genes in the sample AQ1. It is also found four new nitrogen-fixing (nifH) genes. They are AQ1-12(KC412109), Q4-3(KC412133), AQ4-4(KC412133) and AQ4-5(KC412133), among which AQ4-3(KC412133), AQ4-4(KC412133) and AQ4-5(KC412133) are the dominate genes in sample AQ4.

Key words: alpine steppe in the Qilian Mountains, alkali soils, nitrogen-fixing microorganism, nifH genes, community structure

中图分类号: 

  • Q938