在横断山区马先蒿属植物是辐射分化的典型类群，大多数种类为该地区特有，但是到目前为止，如此丰富多样的马先蒿物种的形成和分化机制尚不十分清楚。本研究选择该地区特有的斗叶群中大王马先蒿复合群为研究对象，包括了大王马先蒿、灌丛马先蒿和杯状马先蒿，它们是研究物种分化机制的理想材料。该复合群满足了同域物种形成中的标准：1）该复合群是一个单系群，物种间是姐妹关系；2）分布区完全重叠，且存在同域分布居群；3）有效的花部隔离机制。本研究将利用谱系地理学研究方法，检验该复合群的生物地理和进化历史，验证同域物种形成可能性的这一标准；结合细胞核型的分布式样，探寻染色体重组或多倍化是否在物种分化过程扮演了重要角色。利用共显性的SSR分子标记和人工杂交试验，评价种间基因流强度和种间生殖隔离指数，评估物种形成所处的阶段和花冠分化在物种形成中的作用。以期为横断山区马先蒿属物种形分化和多样性保护提供重要理论依据。

Pedicularis is a genus of adaptive radiation in the Hengduan Mountains, with more than half of species endemic to this small region. Pedicularis exhibits striking diversity and variety in the Hengduan Mountains, however, we less know about the reasons and processes of speciation and species divergence. In this project, we will choose Pedicularis rex complex as the subject to investigate speciation process. This complex includes P. rex, P. thamnophila and P. cupuliformis, and their systematics and pollination biology is resolved well. Therefore, this complex is an ideal exampler to study the issue of speciation. Previous results showed that the rex complex corresponds to three of four criterions for sympatric speciation: (i) they are monophyletic group and sister species, (ii) their distributions are completely overlapped, and (iii) floral divergence mediate effectively reproductive isolation. The main goal of this project is using the phylogeographic approaches to explore whether their biogeography and evolutionary history are sympatric or not allopatric or parapatric. In order to clarify this issue, population samplings of all taxa covering distribution region could be included. Two or three chloroplastic genes will be selected to sequence, and five and six SSR loci to amplify for all population samples. Meanwhile, cytologic karyotype and ploidy are also investiged as population level, and hand hybridizations between taxa and/or populations are conducted in selected populations. The haplotypic data of DNA sequences are used to analyze evolutionary history of species and populations, and using the Cytologic data to examine whether speciation is associated with chromosomal variation. Gene flow caculated by SSR data, and fitness of hybrids can evaluate whether reproductive isolation is completed, as well as the importance of floral isolation inducing reproductive isolation. Whether speciation of Pedicularis rex complex is sympatric or not, this study will provide a valuable case for origin of endemic species in the Hengduan Mountains.