风毛菊属雪莲亚属和雪兔子亚属的分类学研究

Subgenera Amphilaena and Eriocoryne belong to the most species-rich and evlutionarily rather radiative genus Saussurea in the Asteraceae. Approximately 62 species are currently recognized in the two groups, with 55 already documented to occur in China. Some of the species are the botanican origin of the famous traditional Chinese herbal medicine 'Xue Lian Hua'(literally meaning 'Snow Lotus'). Mainly distributed on high screes of the Qinghai-Xizang (Tibetan) Plateau with a harsh environment, species of the two subgenera often share particular morphological characteristics such as rosette growth forms, making them look very alike in appearance. Owing to the scantiness of herbarium specimens available for research, the poor knowledge of many macro- and micro-morphological characters, and the insufficent analysis of the character variation, many taxonomic problems remain unresolved in the two subgenera, such as ambiguous species demarcation, discrepancy in taxonomic identity, and species misidentifications. This project aims to conduct a thorough taxonomic revision of the two groups using multidisciplinary approaches. We will make a comprehensive survey of all the major macro- and micro-morphological characters (such as floral micromorphology, palynology, and cytology), evaluate their variation patterns, and determine their taxonomic applicability. We will also perform a molecular phylogenetic analysis to test the monophyly of the two subgenera, and evaluate the phylogenetic relationships. Evidence from all these sources will then be incorporated in our decisions on species delimitation, and finally all the species will be correctly named according to the type method. This project will greatly improve the taxonomy of the genus Saussurea, and aslo provide important basic scientific data for the reasonable utilization and effective protection of the 'Xue Lian Hua' resources in China.

菊科风毛菊属雪莲亚属和雪兔子亚属很多种类是我国著名民族药"雪莲花"的原植物，全世界约62种，我国约55种，其中绝大部分种类分布于青藏高原。由于生长于高寒生境，性状存在明显的趋同进化，加之很多种类标本很少，性状研究存在不少空白，所以对这两个亚属的分类处理十分困难。目前两个亚属中都存在较多明显的分类学问题(如种间界限不清、名实不符、种类鉴定错误等)。本项目拟通过文献考证、标本室和野外居群考察及实验室研究，充分利用多学科证据（包括花部微形态学、花粉学、细胞学和分子系统学等）深入揭示这两个类群各主要性状的变异式样，评价各性状的分类学价值以进行合理的种类划分，最后根据模式方法给予这些种类以正确学名，从而完成对这两个亚属的全面分类学修订。本项目将促进风毛菊属这一种类极多的大属的分类学研究，同时为"雪莲花"这一我国珍贵药用植物资源的利用和保护提供基础科学资料。

开展了我国青藏高原地区、西北地区、华中地区、东北地区和华北地区等地的深入野外考察与大量实验材料采集, 采集风毛菊属植物1200余号。在大量野外考察和标本研究的基础上，发表了青藏高原及临近地区风毛菊属新种40个，其中包括雪莲亚属和雪兔子亚属8个新种。完成Flora of Pan-Himalaya (即《泛喜马拉雅植物志》)风毛菊属的编写和出版，完成对泛喜马拉雅地区风毛菊属的分类修订和专著性工作，该地区包括了雪莲亚属和雪兔子亚属的绝大部分种类。该著作中的分类处理包括把17个学名处理为异名（synonyms），选定了27个学名的后选模式，提出5个新组合。. 另外通过形态学和分子系统学研究，我们发现重羽菊属（Diplazoptilon）在系统树中位于风毛菊属之内，结合微形态性状和分子系统学证据，我们认为羽毛状外层冠毛的性状不足以区别风毛菊属，因此重羽菊属应该归并到风毛菊属之中。. 在充分考虑类群代表性和地理分布代表性的情况下，我们选取了风毛菊属植物共263种441样品及其近缘属7个属11个样品，进行了系统发育分析：利用4个叶绿体基因片段 (ycf1、rpl32-ndhF、psbA-trnH、trnL-F) 和1个核核糖体基因 (nrDNA) 片段 (ITS)对风毛菊属进行了初步的系统发育分析。结果表明：(1) 风毛菊属为支持率很强的单系，其姐妹类群为肉木香属 (Polytaxis)；(2) 风毛菊属属下的传统分类等级大部分不是单系；(3) 风毛菊属植物被重新划分为5个大的分支，但5个分支之间的关系尚不明确，有待更进一步的研究。通过分子钟估算，初步估算出风毛菊属的起源和分化之间。