染色体进化(包括多倍化和非整倍化)一直是生物进化领域倍受关注的焦点，运用似然法模型在分子系统与生物地理演化的框架内来推导一个类群在不同时空下的染色体进化规律是一个全新的研究热点。黄精族是一个非常理想的进行这方面研究的类群，仅包括4属110余种；各个属呈现不同的染色体进化模式；另外其地理分布也非常有研究意义，存在多个东亚-北美间断，并且以青藏高原和横断山区为多样化中心。本项目拟在对黄精族各类群进行全面取样的基础上开展多分子序列(包括叶绿体和核基因)的系统发育和生物地理进化研究，以及不同地域的物种分化速率分析。然后在此基础上综合细胞学数据运用似然法模型，重点开展黄精族的祖先染色体数目及其演变历史的分析,并探讨其染色体进化在东亚与北美间断中的差异性分化、在青藏高原和横断山区高度多样化的演化特点、以及与青藏高原抬升过程中的物种进化速率的关系，这对揭示物种形成在染色体水平上的进化规律具有重要意义。

Chromosomal evolution including polyploidy and aneuploidy is always an interesting focus in evolution and attracted much attention from scientists. It is a new field to study the relationship between chromosomal evolution and origin and formation of species under the framework of phylogeny and biogeography using likelihood models. The monophyletic tribe Polygonateae is an ideal group to study chromosomal evolution in this context. It contains only 4 genera with ca. 110 species. The four genera have different patterns of chromosomal evolution. Furthermore, the tribe Polygonateae exhibits multiple eastern Asian - North American disjunctions with most species from Asia, especially from the Qinghai-Tibetan Plateau and the Hengduan Mountains of SW China. Based on a comprehensive sampling scheme, this project uses multiple molecular markers (including both chloroplast and nuclear) to investigate the phylogeny, biogeography, and speciation rates of Polygonateae. Then combined with cytological data, we will use Polygonateae as a model to examine chromosomal evolution in plant speciation in view of phylogeny and biogeography, especially chromosomal differentiation between eastern Asia and North America, diversification pattern in the biodiversity hotspot of SW China and its correlation of speciation rates during the uplift of Qinghai-Tibetan Plateau. This project should benefit our understanding of chromosomal behavior in species evolution and diversification.