点地梅属（报春花科）的系统学与生物地理学

温带植物群系在北半球的间断分布格局是如何形成的，这一直是历史生物地理学所关心的问题。近年来生物地理学研究又取得了长足的进展，这得益于系统发育重建中DNA序列数据的大量增长，地理分歧时间的估计，和地理区域分析的方法学上的发展。本项目拟以报春花科点地梅属为例子，深入研究其系统学和历史生物地理学。项目将在北温带范围内对本属材料广泛取样，以覆盖属下所有主要的分类群和其主要地理分布区域，并测定更多的基因组区段序列，以构建系统树，估价种间关系；运用松懈的分子钟方法，估计系统树上各分支节点分歧分化的时间。在此基础上，运用多种地理区域分析方法，探讨点地梅属的生物地理学，特别是推论其祖先地理区域和在北半球温带的迁移路径。通过历史生物地理学研究，可以追溯生物类群过去时空分化的历史，这可以帮助理解现代生物区系分布的历史成因，对制定相应的生物多样性保护策略也有重要的指导意义。

The discontinuous distributions of the temperate forest around the Northern Hemisphere have attracted considerable attention from biogeographers.?Recently the study of biogeography has progressed steadily benefiting from the exponential increase of DNA sequence data from molecular systematic studies, and new tools for divergence time estimation and geographic area analysis. This project is to study the systematics and biogeography of the genus Androsace(Primulaceae). With increasing sampling from around the Northern Hemisphere, which will cover the main infrageneric groups and main geographic distribution areas of Androsace, and sequencing DNA regions from more plastid and nuclear genomes,this study is to reconstruct the phylogeny of Androsace, which represents species relationships, and to estimate the divergence time for individual clades in the phylogenetic trees using relaxed molecular clock. On the basis of this, to infer the ancestral area and migration pathways of Androsace with various analytical methods of geographic area analyses. The study of biogeography may provide insights into the temporal and spacial diversification history of biome, which enhance our understanding about the causal factors of the distribution pattern of extant floras, and meanwhile offer clues for the establishment of conservation strategies of biodiversity.