菊科紫菀属的分类学研究

Among the family Asteraceae, Aster is a taxonomically troublesome giant genus. Most of its species are found in Asia. There are many confounded issues in its present taxonomy, including the lack of clearly defined generic boundary, confusing identities of a large number of species, and puzzling morphological variations. The project will resolve these confusions by selecting appropriate molecular markers, reconstructing the phylogenetic relationships for Aster and all the minor genera that are closely related to Aster, acquiring new micromorphological, cypsela anatomical, cytological characters, recognizing symplesiomorphic features, thus clarifying its generic circumscription. Consequently, the project will clarify the true identities of its entire species and revise its taxonomy using morphological-geographical methods. Comprehensive evidences will be used to revise some confusing groups of Aster. The researchers intend to study the character variations within and among populations of these complex species using biological statistic methods. Ecological and geographical information will also be summarized to help delimitate the species. All these characters will be combined and evaluated together to get a reasonable taxonomy. This project will resolve the taxonomic problems of such an important taxon in the sunflower family. Furthermore, the project will promote the resolution of the similar problems in other giant genera of the flowering plants.

紫菀属是主要分布在亚洲的一个大属，分类比较混乱，是菊科植物分类的难点，主要是：属的界限模糊不清；属下种类亟待修订，包括名实混乱、重要性状变异不清楚等。本研究将筛选合适的分子标记，重建紫菀属及其近缘类群的系统发育关系，同时展开形态学、微形态学、瘦果解剖学和细胞学研究，以期发现一些新的分类学性状，寻找共近裔性状，从而理清紫菀属的界限；我们还将清理现存紫菀属分类中存在名实问题，以地理－形态方法整理该属，对分类上比较困难的类群进行综合研究，以居群的概念为指导，借助生物统计学的方法分析性状在居群内和居群之间的变异，以期解决紫菀属内复杂的性状变异，并结合生态、地理资料确定种的划分，从而全面修订紫菀属。本研究的完成不仅可以解决菊科内部这样一个重要类群的分类学问题，而且有助于推动解决与之类似的有花植物其他大属的分类学问题。

紫菀属是一个大属，主要分布在亚洲，分类比较混乱，是菊科植物分类的难点，主要是：属的界限模糊不清；属下种类亟待修订，包括名实混乱等。我们在欧亚大陆展开了广泛的野外考察，仔细观察了大量的性状，结合移栽及统计分析的，澄清了紫菀属内部分种类的混乱，并发表了新类群。我们展开了形态学、微形态学和瘦果解剖学研究，发现紫菀属及其近缘属在瘦果肋的数目、分泌腔有无、中果皮肋的厚度、中果皮的薄壁细胞的层数和厚壁组织的层数等性状上存在着丰富的变异，这些性状可以帮助解决确定紫菀属的界限。本项目开发了新的叶绿体基因和和核基因标记，结合形态学、微形态学和瘦果解剖等多学科分类证据，探讨了紫菀属及其近缘属的界限。项目无论在取样广度还是研究性状的数量上，都有所突破。最后，结合分子系统学证据及其他证据，我们提出了一个紫菀属分类的新方案。