利用流式细胞仪分选技术研究湖泊真核超微藻的遗传多样性

Use of Flow Cytometric Sorting to Assess the Diversity of Eukaryotic Picophytoplankton of Lakes

利用流式细胞仪分选技术及PCR、构建基因克隆库的方法初步调查了冬季太湖、玄武湖、紫霞湖真核超微藻的遗传多样性及影响因子,以揭示3个湖泊真核超微藻的差异,更全面地了解不同湖泊浮游藻类的群落结构.结果表明不同湖泊真核超微藻多样性存在明显差异,玄武湖以隐藻(Cryptophyta)为主,紫霞湖优势种为隐藻,还有少量金藻(Chrysophyta),太湖真核超微藻多样性较为丰富,有金藻、隐藻、硅藻(Bacillariophyta)、绿藻(Chlorophyta),且不同湖区也有差异.梅梁湾N2点以金藻为主,贡湖湾N4点隐藻、硅藻、绿藻数量相当,但发现较多真菌,靠近大湖区的W2点多样性最为丰富,4种藻均有发现.不同湖泊真核超微藻多样性与环境因子的冗余分析表明,总磷含量与其多样性显著相关.

A novel approach based on flow cytometric sorting followed by construction of 18S rRNA clone libraries was used to study the diversity of eukaryotic picophytoplankton of lakes.The composition of eukaryotic picophytoplankton community appeared highly variable in three lakes.Eukaryotic picophytoplankton was dominated by Cryptophyta in the Lake Xuanwu,and was mainly composed of Cryptophyta and Chrysophyta in the Lake Zixia.In the Lake Taihu,four phyla were discovered,including Cryptophyta,Chrysophyta,Bacillariophyta and Chlorophyta.Meanwhile,the diversity of eukaryotic picophytoplankton differed in various lake regions.In the Meiliang Bay,Chrysophyta was the dominant,and the other three phyla were found in the Gonghu Bay.In the central lake,all of those four phyla were discovered,implying this region contained the highest diversity.The canonical correspondence analysis between the diversity of eukaryotic picophytoplankton and environmental factors revealed the concentration of total phosphorus had the highest important impact on the eukaryotic picophytoplankton communities.