乌梁素海湖滨湿地细菌群落结构多样性

Bacterial diversity in littoral wetland of Wuliangsuhai lake

摘要:

摘要:【目的】了解乌梁素海湖滨湿地水陆过渡带细菌群落结构及多样性变化，探讨富营养化湖泊湿地基质条件对细菌群落结构的影响。【方法】应用变性梯度凝胶电泳( PCＲ-DGGE)技术，分析和比较了依陆向分布的4个水陆过渡带样点的湿地细菌群落结构多样性，采用典型对应分析(CCA)探讨了湿地基质因子对细菌多样性的影响。【结果】DGGE 图谱显示依湖泊水体沉积物(S-1)→湖滨芦苇沼泽沉积物(S-2)→湖滨碱蓬盐化草甸土壤(S-3)→岸上白刺荒漠土壤(S-4)，4个样点的条带数依次减少，对应菌群结构及多样性变化显著;多样性指数分析结果显示，Shannon-Wiener 指数(H)、均匀度(E)、丰富度(S)以及Simpson 指数(DS)均显示依陆向分布逐步下降的规律，即:S-1＞S-2＞S-3＞S-4。序列比对结果显示，沉积物及土壤细菌分属于变形菌门(78.6%)、酸杆菌门(7.1%)、拟杆菌门(14.3%)这3个细菌类群，优势菌门为变形菌门，而变形菌门又分为5个亚群，其中ε变形菌纲为优势亚群;CCA结果表明，图中各条带对应物种的分布受铵态氮、总氮、有机碳、水溶盐总量、氯离子以及钾离子影响最大。【结论】乌梁素海富营养化湖泊的水陆过渡带湿地细菌群落结构存在较大差异，富营养化相关基质因子对细菌多样性影响较大。这为研究富营养化湖泊湿地水陆过渡带的细菌结构多样性及空间异质性提供了科学依据。

Abstract:

Abstract:［Objective］The aim of this study was to analyze the bacterial diversity of land-water transition zone in littoral wetland of Wuliangsuhai Lake，and to study the effect of eutrophic substrate on the bacterial composition．［Methods］The denaturing gradient gel electrophoresis (DGGE) with PCＲ-amplified 16S rDNA fragments was used to determine bacterial diversity，and the ordination technique of canonical correspondence analysis (CCA) was used to evaluate its effects on bacterial community composition．［Results］DGGE result shows that the microbial quantity decreased gradually from eutrophic lake sediment to desert soil．Diversity index analysis shows that the Shannon-Wiener index (H)，Evenness index (E)，richness index (S) and Simpson index (DS) decreased gradually from water to land (eutrophic lake sediment＞swamp sediment ＞ saline soil ＞ desert soil)．Based on the sequencing results，there are 3 phyla in 4 samples，including Proteobacteria (78.6%)， Acidobacteria (7.1%)，Bacteroidetes (14.3%)， Proteobacteria (52.6%) were dominant species，in which the Epsilon proteobacteria were predominant subgroup．The results of CCA suggest that that NH4 + -N，total nitrogen，organic carbon，total soluble salt，Cl－and K + have most significant influenced the distribution of bands related species．［Conclusion］The bacterial community structure of transition zone in Wuliangsuhai wetland differed significantly，and eutrophic relative factors had a strong impact on the bacterial community structure．This work presented a certain reference for the preliminary understanding of the bacterial composition and diversity and provided a scientific foundation for the research of spatial heterogeneity in this transition zone．