剑湖湿地茭草根际土壤固氮菌多样性分析

2012年采用PCR-DGGE法对云南省典型高原湿地---剑湖地区的典型水生植物茭草的根际土壤固氮菌多样性进行分析。结果显示，入水口永丰河的茭草根际土壤固氮菌Shannon-Wiener指数和Simpson丰富度最高，出水口黑惠河的茭草根际土壤固氮菌Shannon-Wiener 指数和Simpson丰富度最低。典型对应分析表明， NH4＋和NO3-显著影响根际土壤固氮菌群落结构。同源比对分析显示，所有序列共分为2个类群，其中有11条带属于Betaproteobacteria ，占84.6％；2条带属于Gammaproteobacteria ，占15.3％。聚类分析结果表明，大部分固氮菌（84.6％）属于红环菌目，少部分（15.3％）属于着色菌目。

Nitrogen-fixing Bacteria Diversity in the Rhizosphere Soil of Zizania caduciflora in Jianhu Wetland

The diversity and community structure of nitrogen-fixing bacteria in the rhizosphere soil of Zizania caduciflora roots were investigated by using denaturing gradient gel electrophoresis （ DGGE ） . The results showed that Shannon-Wiener index and simpson index nitrogen-fixing bacteria of rhizosphere soil of Zizania caduciflora in Yongfeng river were the highest , while the lowest index were found in Heihui river .The result of canonical correspondence analysis of the relationships between nitrogen-fixing bacteria and soil chemical parameters showed that NH4^＋and NO3^-had an significiant impact on nitrogen-fixing bacteria community.The sequence comparison analysis showed that all sequences could be divided into two groups , namely Betaproteobacteria and Gammaproteobacteria, and among these, 11 belongs to Betaproteobacteria （ accounts for 84.6 %）, and 2 blongs Gammapro-teobacteria （accounts for 15.3 %）.In addition, The result of cluster analysis based on DGGE sequences showed that most nitrogen-fixing bacteria belongs to Rhodocyclales （ accounts for 84.6%） , and only small portion belongs to Chromatiales （15.3 %）.