基于高通量测序的鸭河口水库微型浮游生物群落分析

High-throughput sequencing for the study of nanoplankton community composition in Yahekou Reservoir

采用高通量测序结合显微镜计数的方法研究了鸭河口水库微型浮游生物群落组成.结合OTUs数、多样性指数分析、稀释性曲线、PCA分析和UPGMA分析,浮游生物群落多样性排序为:库心>坝下.高通量测序表明库心和坝下微型浮游生物分布于38个和33个门,浮游植物有隐藻(Cryptophyta)、绿藻(Chlorophyta)等4个门,浮游动物主要有微型后生动物(Metazoa)、双鞭毛虫(Dinoflagellata)、丝足虫(Cercozoa)等8个门,表明两组样品具有丰富的群落组成.显微镜计数法共检测出库心和坝下区域浮游植物6门和浮游动物1门,共28个属,浮游植物主要为绿藻(Chlorophyta)、隐藻(Cryptophyta)、硅藻(Bacillariophyta)等,浮游动物只检测到轮虫动物门(Rotifera).比较两种方法,高通量测序能检测到更丰富的浮游生物群落信息,传统的显微镜计数法能对物种鉴定更精确,两者结合使用,能取长补短,推动浮游生物群落及功能研究.

This study is aimed at investigating the nanoplankton community composition in Yahekou Reservoir using high-throughput sequencing and classical light microscopy. Based on the rarefaction curves of high-throughput sequencing, the number of OTUs, principal coordinate analysis （PCA） , and UPGMA, the samples obtained from the center of the reservoir had higher diversity and species evenness. Phylogenetic analysis showed that the nanoplankton community composition could be divided into 38 and 33 major phylogenetic groups by phyla, the predominant phytoplankton groups included Cryptophyta, Chlorophyta, Chrysophyta, and Bacillariophyta while the zooplankton groups included Metazoa, Dinoflagellata, Cercozoa, Ciliophora, Centrohelida, Stramenopiles, Amoebozoa, and Euglenozoa. In this study, nanoplankton composition was characterized by high-throughput se- quencing and classical light microscopy, and the results of these analyses were compared. High-throughput se- quencing detected more species than light microscopy did, and thus gave a better assessment of nanoplankton di- versity. However, high-throughput sequencing of 18S rDNA sequences amplicons did not adequately identify na- noplankton at the species level, while light microscopy did. In summary, a combined strategy using both morphological and molecular techniques is recommended.