珍稀细叶石斛的谱系分化及其遗传多样性形成的时空格局与机制

Dendrobium hancockii Rolfe is a rare and endangered endemic perennial herb, and its wildlife resources are gradually leanness even extict. It is imperative to launch a research to study and protect wildlife germplasm. In this project, some cpDNA and nDNA molecular markers of Dendrobium hancockii will be used for inferring its haplotype network and reconstructing haplotype phylogenetic trees. The ancient haplotype, its distribution area and the center of origin of Dendrobium hancockii will be defined by using a series of analysis softwares, such as MrBayes, PAUP, DnaSP, Arlequin, Network. Based on the references of genetic drift, bottleneck effects and natural selection, series of studies will be carried out such as the population differentiation, glacial refugial regions, diffusion routes and its divergence time. Ecological niche modeling will be constructed using MAXENTT and DIVA-GIS. SNP markers which are developed using RAD-seq technique will be combined with nDNA SSR markers to detect genetic diversity and population structure of Dendrobium hancockii by means of a series softwares such as STACKS, Structure, AMOVA and IBDWS. Based on the genetic resource assessment and conservation genetics, it is helpful for determining several evolutionarily significant units（ESUs）and providing the reasonable conservation strategies for Dendrobium hancockii. Those molecular markers will also be used for good argricultural practice (GAP) and authentication of the germplasm of Dendrobium hancockii.

珍稀细叶石斛野生资源日趋濒危匮乏，研究和保护其野生种质已成燃眉之急。本项目拟利用细叶石斛cpDNA、nDNA的分子标记，运用MrBayes、PAUP、DnaSP、Arlequin、Network等系列分析软件，构建各居群的系统发育树及单倍型网络图、确定古老单倍型和起源中心；阐述遗传漂变、瓶颈效应、自然选择等因素对细叶石斛群体遗传变异的影响，推测其冰期避难所、冰后期迁居路线、居群扩张等谱系分化的时空格局与机制。利用MAXENT、DIVA-GIS软件进行生态位模型分析。还将利用RAD-seq法开发细叶石斛基因组SNP位点，结合核SSR分子标记，运用STACKS、Structure、AMOVA等软件，分析细叶石斛的遗传多样性、遗传结构，对其进行保护遗传学研究，确定细叶石斛居群的若干基本保护单元，并提出合理的保护策略。还将筛选具有居群种质鉴别意义的分子标记，为细叶石斛种质鉴别和GAP生产提供依据。

我国特有的珍稀细叶石斛野生资源日趋濒危匮乏，研究和保护其野生种质已成燃眉之急。本项目拟利用细叶石斛cpDNA、nDNA的分子标记，运用MrBayes、PAUP、DnaSP、Arlequin、Network等系列分析软件，构建各居群的系统发育树及单倍型网络图、确定古老单倍型和起源中心；阐述遗传漂变、瓶颈效应、自然选择等因素对细叶石斛群体遗传变异的影响，推测其冰期避难所、冰后期迁居路线、居群扩张等谱系分化的时空格局与机制。利用MAXENT、ARC-GIS软件进行生态位模型分析。还将利用RAD-seq法开发细叶石斛基因组SNP位点，结合核SSR分子标记，运用STACKS、Structure、AMOVA等软件，分析细叶石斛的遗传多样性、遗传结构，对其进行保护遗传学研究，确定细叶石斛居群的若干基本保护单元，并提出合理的保护策略。还将筛选具有居群种质鉴别意义的分子标记，为细叶石斛种质鉴别和GAP生产提供依据。