太湖浮游细菌种群基因多样性及其季节变化规律

Phylogenetic diversity and seasonal variation of bacterioplankton communities in Lake Taihu

为认识湖泊中浮游细菌的多样性及其变化规律,本研究采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)的方法,研究了太湖梅梁湾和湖心区浮游细菌种群16S rRNA基因多样性以及种群基因组成的季节变化特征．研究结果表明,太湖浮游细菌种群具有丰富的基因多样性．浮游细菌的丰度、DGGE条带数、种群的Shannon-Wiener指数、Simpson指数和Pielou指数均呈现显著的季节变化规律:夏季及秋季浮游细菌的丰度、基因多样性及种群的均匀度较高,而冬季和春季则较低．浮游细菌种群的基因组成随时间变化．梅梁湾浮游细菌的丰度显著高于湖心．梅梁湾与湖心浮游细菌主要建群种的基因型存在显著差异．

The phylogenetic diversity and seasonal variation of the bacterioplankton communities were determined using denaturing gradient gel electrophoresis （DGGE） of PCR-amplified bacterial 16s rRNA genes at Meiliang Bay and lake center in Taihu. Results indicated that the bacterioplankton community composition was diverse in Lake Taihu. At the two sampling stations, bacterioplankton abundance, DGGE band number, Shannon-Wiener index, Simpson index, and Pielou index all showed significantly seasonal variation during the sampling period. Bacterloplankton abundance, diversity and evenness were all higher in summer and autumn than in winter and spring. The phylogenetic types of the bacterioplankton communities changed during the sampling period. The abundance of bacterioplankton was significantly higher at Meiliang Bay than at the open lake. The main edificators of the bacterioplankton communities may have different phylogenic types at Meiliang Bay and lake center.