中国海网地藻目的分类学研究

Dictyotales is one of the major members in warmer marine ecosystem, and occupies a very important position in the evolutionary history of brown algae. It differs distinctly from the other brown algae in apical growth, formation of tetraspores and haplodiplontic isomorphic life cycle, and has been suggested to be an ancient group of brown algae. However, many basic but significant questions such as taxonomy and geographical distribution of Dictyotales are still poorly understood. This project will carry out a study on taxonomy of Dictyotales occurring in China Seas, based on the integration of field investigations, morphological structures, embryogenic and multi-gene phylogenetic analyses. The targets are 1) to find out the component species and the regularity of geographical distribution in our country; 2) to clarify systemic relation among various genera and to discover new taxa; 3) and to analyze the geographic distribution patterns of genetic diversity of several representative species. The implement of this research will update our knowledge about the taxonomy and biogeography of Dictyotaceales in China Seas, provide a basic data set and platform for the further research on this biological group, and provide scientific basis for the protection and rational utilization of algal resource of our country.

网地藻目藻类是暖海生态系统中的重要成员，其在褐藻的进化史上占据着极其重要的位置。从顶端生长、四分孢子形成和同型世代交替生活史等特征看，网地藻目明显不同于其他褐藻，被认为是一个古老的褐藻类群。然而关于网地藻目的分类和分布等基本科学问题仍有待于深入研究。本项目拟采用实地调查、形态学、胚胎发生学和分子系统发生学相结合的方法，对中国海网地藻目进行分类学研究。目的在于：1）摸清我国网地藻目种类构成和地理分布规律；2）阐明属间的系统演化关系，发现新的分类单元；3）揭示几个代表种的遗传多样性地理分布模式。本研究不仅可填补中国海网地藻目分类及生物地理学研究的长期空白，为该生物类群的后续深入研究打下基础，而且可为我国海藻资源的保护和开发利用提供重要科学依据。

在传统分类中网地藻目只包含一个网地藻科。虽然此类群是暖海生态系统的重要成员，但是关于中国海的网地藻科的分类和分布等仍有待于进一步研究。本项目采用实地调查、形态观察和分子系统分析相结合的方法，对中国海网地藻科进行分类学进行研究。首次对我国产网地藻科的各种进行DNA分子标记，初步摸清我国网地藻科的种类构成和地理分布，澄清了各个分类单元的系统发育关系，建议设立新科和属来对分类网地藻目进行分类学修订，发现了中国海产的几个新种和新记录。本研究拓宽了我们对网地藻科的分类学以及生物地理学的认识，为该生物类群的后续深入研究打下基础，也为我国海藻资源的有效保护和合理利用提供重要科学依据。