四川核桃主产区根际土壤固氮细菌筛选及多样性研究  

Screening and Diversity of Nitrogen Fixation Bacteria in the Rhizosphere Soil in the Major Walnut Production Region of Sichuan

作　　者：李姝江[1] 朱天辉[1] 崔晓亮[1] 

机构地区：[1]四川农业大学林学院,四川雅安625014

出　　处：《土壤通报》2014年第1期199-204,共6页Chinese Journal of Soil Science

基　　金：国家自然科技资源共享平台项目(2005DKA21207-13)资助

摘　　要：利用Dobereiner低氮培养基通过平板稀释法从四川核桃主产区的根际土壤中分离筛选高效固氮细菌,采用形态学、生理生化和分子生物学鉴定到种,并研究其生物量与土壤养分之间的关系,再通过Shannom-Wiener指数、丰富度指数、Pielou指数和Simpson指数对其多样性进行评价。结果显示,初筛固氮细菌89株,乙炔还原法测定其固氮酶活性复筛后,得到具有较好固氮能力的菌株25株,属于9个属,假单胞菌属和固氮菌属为优势。土壤养分与固氮细菌生物量的相关性表明,除与土壤有机质呈极显著正相关、与有效N呈显著正相关外,与其余指标均无相关性。在多样性研究中,巴中南江和宜宾兴文两地的固氮细菌种群丰富,其多样性和丰富度指数均较大。土壤养分与固氮细菌多样性的相关性表明,多样性指数、丰富度指数与土壤有机质分别呈极显著、显著正相关,与全N呈显著正相关,与有效N呈极显著正相关;均匀度指数与有效N呈显著正相关。The efficient nitrogen fixation bacteria were screened from the rhizosphere soil of walnut on Dobereiner low nitrogen culture medium in major production region of Sichuan. The species were identified by morphology, biochemistry and molecular biology, and the correlation between the biomass and the soil nutrition was studied. The diversity of efficient nitrogen fixation bacteria was evaluated by Shannom-Wiener index, richness index, eveness index and Simpson index. The results showed that there were 89 strains of nitrogen fixation bacteria in first screening, while 25 strains of efficient nitrogen fixation bacteria classified into 9 genus were obtained after further screening in terms of the nitrogenase activity by acetylene reduction method, and the bacteria in the genus of Pseudomonas and Azotobacter were dominant groups. The correlation between the biomass of nitrogen fixation bacteria and the soil nutrient showed that there was no correlation between them, except the remarkably significantly positive correlation with the organic matter and the significantly positive correlation with the available N. In the study of diversity, the population of nitrogen fixation bacteria was rich in Nanjiang, Bazhong and Xingwen, Yibin with high Shannom-Wiener index and richness index. The correlation between the soil nutrient and the diversity index of nitrogen fixation bacteria showed that Shannom-Wiener index and richness index presented remarkably significantly and positive correlations with the organic matter, meanwhile had significantly positive correlation with total N and available N. Eveness index had remarkably significantly positive correlation with available N.

关 键 词：核桃 根际土 固氮细菌 多样性 

分 类 号：S182[农业科学—农业基础科学]