虎耳草科虎耳草属石荷叶组的分类学研究

Section Irregulares, of great medicinal and horticultural value, is the basal group of the genus Saxifraga (Saxifragaceae). It has ca. 18 species widely distributed from southern and north-eastern China, through Korea to Japan, with centers of diversity in both south-western China and Japan. It was last monographed in 1919 by Engler and Irmscher, and much new material is now available, including the description of eight new species (seven from China) within the last 40 years. The number and division of species in Irregulares is under debate. Therefore, a comprehensive systematic revision is needed. Also, a more completely sampled molecular phylogenetic study is required to test the monophyly of Irregulares. This project will analyze the main taxonomic characters, by observation of specimens from herbarium and field surveys, to establish the range of variation. DNA sequence data will be added to improve group definition and to revise the section. The project aims to resolve the problems in the classification and nomenclature of Irregulares, for the utilization of its resources, and shed some light into the distribution pattern of Saxifraga in Asia.

虎耳草科虎耳草属的基部类群石荷叶组具有很大的药用及观赏价值，含18余种，广泛分布自我国南部、东北部、朝鲜半岛至日本，分化中心为中国西南部及日本。自1919年Engler和Irmscher的全面整理之后，新增了较多标本和研究材料，最近40多年中增加了8新种，其中7种来自我国。石荷叶组内种的数目和划分一直存在较多争议，该组需要全面的分类修订。而且，该组缺少取样较为完全的分子系统学研究以证实其单系性。本项目通过馆藏标本研究结合野外考察，将对石荷叶组植物的主要分类特征进行综合分析，观察变异式样，结合DNA序列数据处理组下分类群，开展全面及系统的分类修订。本项目的目标在于澄清石荷叶组在分类和命名上的问题，为本组植物资源的开发利用提供依据，并对于揭示虎耳草属在亚洲的分布式样有重要意义。