Li Ran, Jiao Nianzhi, Warren Alan, Xu Dapeng
State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
Department of Life Sciences, Natural History Museum, London SW7 5BD, United Kingdom.
Eur J Protistol. 2018 Apr;63:72-82. doi: 10.1016/j.ejop.2018.01.004. Epub 2018 Jan 31.
Protists make up an important component of aquatic ecosystems, playing crucial roles in biogeochemical processes on local and global scales. To reveal the changes of diversity and community structure of protists along the salinity gradients, community compositions of active protistan assemblages were characterized along a transect from the lower Pearl River estuary to the open waters of the South China Sea (SCS), using high-throughput sequencing of the hyper-variable V9 regions of 18S rRNA. This study showed that the alpha diversity of protists, both in the freshwater and in the coastal SCS stations was higher than that in the estuary. The protist community structure also changed along the salinity gradient. The relative sequence abundance of Stramenopiles was highest at stations with lower salinity and decreased with the increasing of salinity. By contrast, the contributions of Alveolata, Hacrobia and Rhizaria to the protistan communities generally increased with the increasing of salinity. The composition of the active protistan community was strongly correlated with salinity, indicating that salinity was the dominant factor among measured environmental parameters affecting protistan community composition and structure.
原生生物是水生生态系统的重要组成部分，在局部和全球尺度的生物地球化学过程中发挥着关键作用。为揭示原生生物多样性和群落结构沿盐度梯度的变化，利用18S rRNA高变V9区的高通量测序技术，对从珠江口下游到南海开阔水域的一个断面的活跃原生生物群落组成进行了表征。本研究表明，淡水和南海沿岸站点的原生生物α多样性均高于河口站点。原生生物群落结构也沿盐度梯度发生变化。硅藻门的相对序列丰度在盐度较低的站点最高，并随盐度升高而降低。相比之下，囊泡虫类、单鞭毛生物和有根虫类对原生生物群落的贡献通常随盐度升高而增加。活跃原生生物群落的组成与盐度密切相关，表明盐度是影响原生生物群落组成和结构的测量环境参数中的主导因素。
