北方近岸环境中寡毛类纤毛虫的多样性与系统学

The marine planktonic ciliates play very important roles in the transfer of energy and matter through the microbial food web by consuming a majority of the primary production. As an important component of marine microplankton, oligotrich ciliates are quite rich in species and quantity. However, due to various reasons, the study on the systematics and biodiversity of this group is still insufficient. So far, domestic related work is mainly confined to the southern tropical and subtropical waters. Study of oligotrichs in the northern coast is not enough. Many taxa are still unknown, which should be further explored. This study will focus on the oligotrich ciliates in the Chinese northern coastal environment, with the Yellow Sea and Bohai as the main sample collection sites. Meanwhile, the related literatures will be sorted out in large scale, and more detailed morphological features will be described by combining of protargol impregnation. This work will complement and refine the DNA database of oligotrich ciliates, by providing multi-gene information of some key taxa as well as secondary structures of rRNA. Finally, to further discuss the species diversity and phylogeny, their morphology, phylogenetic topology and secondary structures will be comprehensively analyzed.

海洋浮游生纤毛虫在水体微型食物网及生态系统的物质循环和能量流动中起重要的枢纽作用。作为其中重要组分的寡毛类纤毛虫，在种类数量及丰度上均相当丰富，却因多种原因，国际间对该类群的系统学及生物多样性的研究仍存在严重不足，国内工作也主要局限于南方热带-亚热带水体，北方近岸环境中的寡毛类研究不够深入，大量类群依然不明，亟待深入探索。本研究将以黄渤海为主要采集地，对我国北方近岸环境内的寡毛类纤毛虫展开调查,利用现代银染技术对该类群给出更详细的形态学描述；补充完善寡毛类DNA“分子种库”：提供重要类群的分子信息(SSU rRNA、LSU rRNA、ITS1-5.8S-ITS2等基因)；预测ITS、rRNA高变区的二级结构；综合其形态学、分子系统树、二级结构等信息对该类群的多样性展开探讨及对其系统学的混乱进行厘清,为阐明该类生物的系统进化取得若干有意义的进展。

本项目涉及海洋水体微型食物网的重要组分——寡毛类纤毛虫的生物多样性调查及其系统学研究。该类群在国际间仍有大量未知种有待发现，因此，该类群的分类学、分子系统学、地理区系分布等亟待探讨。为此，三年来，本课题主要围绕北方近岸的各类水体开展了对寡毛类纤毛虫的形态分类、核酸测序、系统亲缘关系等方面的研究。主要成果包括：（1）共采集并鉴定40余种寡毛亚纲及环毛亚纲纤毛虫，其中有5个新种，并对十余种形态学信息不详的种类重新厘定、补充纤毛图式及统计学资料。（2）完成了50余种/种群的DNA提取工作，基于SSU rRNA基因及多基因如LSU rRNA基因信息，对多个种类的系统学进行了探讨。（3）对系统地位存有争议的Halteria属，利用转录组数据对其系统地位进行了补充研究。（4）上述工作已形成8篇研究论文，其中7篇发表在国际主流刊物上。