沉水植物生态修复对西湖细菌多样性及群落结构的影响

摘要

沉水植物的重建是湖泊富营养化修复的关键措施之一.本研究利用在杭州西湖进行的沉水植物生态修复工程,应用基于聚合酶链式反应的变性梯度凝胶电泳(PCR-DGGE)及分子克隆等手段,研究种植菹草和苦草对水体中细菌多样性及群落结构的影响.未进行沉水植物生态修复的湖区细菌以Bacteroidetes(42.9％)、Betaproteobacteria(30.8％)和Verru-comicrobia(14.3％)为主.而种植菹草和苦草后,Bacteroidetes所占的比例分别减少到12.7％和5.3％；Betaproteobacteria则分别提高到52.4％和59.5％；Alphaproteobacteria由4.4％分别提高到19.0％和12.8％.种植菹草后Verrucomicrobia所占比例大幅降低,而种植苦草对Verrucomicrobia的影响不大.沉水植物修复不仅可以改善水质,同时也可以显著提高水体中细菌的多样性,改变细菌的群落结构.%Reconstruction of submerged vegetation is one of the key measures of eutrophication remediation. Using polymerase chain reaction-denaturing gradient gel electrophoresis ( PCR-DGGE) and clone library analysis, we studied the impact of planting Potamogeton crispus and Vallisneria natans on bacterial diversity and community composition in West Lake, Hangzhou, China. Bacteroidetes (42.9% ), Betaproteobacteria (30. 8% ) and Verrucomicrobia (14. 3% ) dominated in the water column from lake areas without submerged macrophytes. On the contrast, the proportion of Bacteroidetes reduced to 12.7% and 5.3% , respectively, after planting Potamogeton crispus and Vallisneria natans. Meanwhile, Betaproteobacteria increased to 52.4% and 59. 5% , and Al-phaproteobacteria increased from 4.4% to 19.0% and 12.8% , respectively. The proportion of Verrucomicrobia reduced substantially after planting Potamogeton crispus, but varied little after planting Vallisneria natans. This study indicates that submerged macrophytes can not only improve water quality, but also increase bacterial diversity, and shape bacterial community composition significantly.