北欧海微微型真核浮游生物的多样性和群落结构及其与环境因子的关系

为探究北欧海微微型真核浮游生物多样性和群落结构的分布特征,本研究于2017年6月采集北欧海一个典型断面的表层海水,利用标靶(18SrRNA基因V4区)扩增结合高通量测序技术研究了水体中微微型真核浮游生物的多样性及群落结构,并探讨了群落结构、优势类群与环境因子之间的关系。结果表明:微微型真核浮游生物群落的主导类群为囊泡虫类(54.61%),主要由甲藻纲(18.42%)和海洋囊泡虫新类群I (23.01%)组成;后鞭毛类占21.55%,其中真菌在各站中都有较高的相对丰度,为18.86%;此外,不等鞭毛类中的硅鞭藻和囊泡虫类中的甲藻在温度较低的站位中分布较多,而海洋囊泡虫新类群I则在温度较高的站位中分布较多。典型相关分析结果表明,温度对微微型真核浮游生物的群落结构有重要的影响。北欧海的水文特征复杂,寒暖流在此交汇,造成了微微型真核浮游生物的群落结构有明显的区域差异。

BIODIVERSITY AND COMMUNITY STRUCTURE OF PICOEUKARYOTES AND INTERACTION WITH ENVIRONMENTAL FACTORS IN THE NORDIC SEAS

To investigate the distribution patterns of picoeukaryote diversity and community structure of the Nordic Seas, water samples were collected along a line in June 2017. High-throughput sequencing based on target gene (the V4 regions of 18S rRNA gene) amplicons was used to study the diversity and community structure of picoeukaryotes. Relationships between environmental factors and dominant groups were also analyzed. The results show that Alveolata (54.61%) dominated the picoeukaryote community, which mainly comprised by Dinophyceae (18.42%) and MALV-I (23.01%). Opisthokonta and fungi accounted for 21.55% and 18.86% respectively in all sequences. In addition, higher proportion of Dictyochophyceae and Dinophyceae was observed at stations with lower temperatures, while larger percentage of MALV-I was obtained at stations of higher temperatures. In addition, temperature played an important role in shaping the community structure of picoeukaryotes as revealed in CCA analysis. Therefore, the complex hydrological environment in Nordic Seas, where cold and warm currents passed through, resulted in the spatial difference in picoeukaryote diversity and community structure.