ITS克隆测序揭示中国沿海表层水中真核浮游生物多样性

摘要

Planktonic communities in surface water play an important roles in the biogeochemical processes,and the biogeographic distribution is usually related to the environmental conditions such as hy-drology.Recently,molecular approaches have become major solutions to investigate eukaryotic community in the marine ecosystem.In this study,ITS1 was used as a DNA marker to estimate diversity of eukaryotic plankton in the surface water of the Chinese coastal waters.Results of BLAST indicated that most of the ITS1 sequences were affiliated with six eukaryotic groups,including Metazoa,Fungi and Alveolata.The a-bundant eukaryotic plankton could classify the sampling sites into five distinct clusters.For each cluster, the dominant phyla exhibited significant geographic variation.Generally,diversity of eukaryotic plankton was significantly related to longitude,latitude,depth,temperature and salinity,presenting a general in-creasing tendency from the north to south of coastal seas.Community dissimilarity of eukaryotes(β-diversi-ty)increased with the increasing geographic distance.These results indicate that the eukaryotic plankton were subject to the geographical limits in the surface water of the Chinese coastal seas.Hereby this study provides molecular data for the biogeographic distribution of eukaryotic plankton along the coast of China.%表层水体中的浮游生物群落在生物地球化学过程中起重要作用,其生物地理分布通常与水文等环境条件相关.近年来DNA测序等方法已成为研究海洋生态系统中真核生物群落的重要工具,在本研究中采用 ITS1作为DNA标记评估我国沿海表层水中的真核浮游生物多样性.BLAST 结果表明,大部分 ITS1序列隶属于6个真核类群,包括浮游动物、真菌和囊泡虫类等.这些主要的真核生物类群可以将采样点分为显著不同的5个聚类,而每个聚类中的特征真核生物门类表现出显著的地理分布差异.总体上,真核浮游生物群落的多样性水平与经纬度、水深、温盐等参数显著相关,自北向南有显著升高的趋势.真核生物群落差异(β-多样性)随地理距离的增加而加大.这提示真核浮游生物在我国沿海表层水中显示出地理限制.本文为中国沿海浮游生物的生物地理研究提供了分子生物学数据基础.