基于PCR-DGGE技术的剑湖湿地湖滨带土壤微生物群落结构多样性分析

Analyzing Soil Microbial Community Structure Diversity from Jianhu Wetland Lakeside Zone Using PCR-DGGE Technique

为了解剑湖湿地湖滨带植物根际土壤中细菌的群落结构特征多样性,应用PCR-DGGE技术对剑湖湿地湖滨带4种植物根际土壤细菌的群落结构进行了研究,根据DGGE指纹图谱,对它们的遗传多样性进行了分析。结果表明,不同植物群落根际和非根际土壤细菌多样性指数(H′)、丰度(S)和均匀度(J)均有所不同,根际土壤细菌多样性指数、均匀度、丰富度均高于非根际,其中茭草根际土壤细菌多样性指数、均匀度、丰富度均最高,说明植物群落类型与土壤微生物多样性的关系十分密切;不同植物群落根际土壤细菌群落结构相似性较高,非根际土壤细菌群落结构相似性较低,在82%的相似水平上聚为4大类群,根际土壤细菌和茭草非根际土壤细菌聚为一类,其余非根际土壤细菌各聚为一类,说明植物群落对微生物群落结构具有一定的影响。对DGGE的优势条带序列分析,同源性最高的微生物分别属于变形菌门(Proteobacteria)、草酸杆菌科(Oxalobacteraceae)、紫色杆菌属(Janthinobacte rium)、杜擀氏菌属(Duganella)、埃希氏菌属(Escherichia)和链球菌属(Streptococcus),它们均为未培养微生物。不同植物群落根际土壤氮磷含量均有所差异,其中茭草根际土壤氮磷含量最高,湿地土壤细菌多样性与土壤有机质、总N、总P的含量呈正相关关系,土壤细菌多样性与土壤pH值呈负相关关系。

This study analyzed the bacterial community structure from the rhizosphere of four plants found in the Jianhu wetland lakeside zone using PCR-DGGE technique. The results showed that soil samples collected from plant rhizosphere and non-rhizosphere displayed significant differences in the Shannon-wiener index,richness and evenness, respectively. With the highest bacterial diversity was found in Zizania latifolia rhizosphere soil, plant community did influence microbial diversity. Community structure similarity was higher in plant rhizosphere than non-rhizosphere soil. Based on 82% community similar levels, two major groups were categorized, with rhizosphere bacteria and Zizania latifolia non-rhizosphere bacteria as one group, and the rest as the other group. Plant community did influence microbial community structure. Additionally, according to the results of sequence analysis of DGGE dominant bands, all bacterial strains were phylogenetically closed to some uncultured microbes, including Proteobacteria, Oxalobacteraceae, Janthinobacterium, Duganella, Escherichia, and Streptococcus. Plant rhizosphere soil nitrogen and phosphorus contents were different. The highest nitrogen and phosphorus contents were found in Zizania latifolia rhizosphere soil. Soil bacterial diversity positively related to soil organic matter, total nitrogen and total phosphorus contents, but negatively related to soil pH.