伞形科“东亚分支”系统学研究进展

Advances in the study of systematics of “East-Asia Clade” in Apiaceae

关键词:  伞形科, 东亚分支, 系统分类学, 中国-喜马拉雅

Key words:  Apiaceae, East-Asia Clade, systematic classification, Sino-Himalayan

摘要:

伞形科作为被子植物中非常重要的类群,一直以来都是分类学研究的热点和难点。分类学家基于分子生物学的证据,正在努力构建一个相对合理,且能够反映各类群系统发育关系的分类系统。东亚分支(East-Asia Clade)正是近年来通过分子生物学手段在构建伞形科新的分类系统过程中命名的分支之一。该分支在地理空间上以东亚为主体,集中分布于中国喜马拉雅区域。在东亚地区复杂的地质演化历史背景下,目前该分支的范围并未准确界定,分支内部复杂的演化关系也尚未解决。东亚分支系统学问题的最终解决,将给芹亚科大系统框架的构建带来新的认识。该文结合最新的分子系统学研究结果,回顾了东亚分支提出的历史背景,东亚分支的建立及其在芹亚科中的系统位置,以及东亚分支各属的界定及其系统关系。目前已有的研究结果表明,东亚分支现有约16个属,在芹亚科系统树上与Komarovieae构成姐妹群关系; 除了Heptaptera、Keraymonia和膜苞芹属外,其余各属均不构成单系,部分属(如滇芎属、茴芹属和瘤果芹属等)的模式种落入芹亚科别的分支。此外,该文还对研究东亚分支的意义以及该分支目前存在的问题进行了讨论,同时指明了其未来的研究方向。

Abstract:

Apiaceae(Umbelliferae), a large and readily identifiable family of flowering plants, with about 3 575 species in 455 genera, is widely distributed in the temperate zone of both hemispheres, mainly in Eurasia and especially in C Asia. As its important phylogenetic position in angiosperm, it has always been a focal point in taxonomic research. With the evidence of molecular biology, taxonomists are trying to construct a relatively reasonable classification system of Apiaceae that can reflect its phylogenetic relationships. The East-Asia clade is erected in the process of constructing a new classification system by means of molecular biology in recent years. It is mainly located in East-Asia and concentrated in the Sino-Himalayan region. However, due to the complicated historical background of geological evolution in East-Asia, the circumscription of this clade is not well defined, and the evolutionary relationship within the clade has also not been resolved. The phylogenetic resolution of the “East-Asia Clade” will bring new insight into the construction of large-scale systematic framework for the Apiacae subfamily Apioideae. In this review, in conjunction with our recent molecular studies, we briefly retrospect the history and progress of the studies on the classification and phylogeny of East-Asia Clade, including its establishment and circumscription, the relationships of genera in the East-Asia Clade. Recent molecular phylogenetic results indicate that the East-Asia Clade consists of about 16 genera, and it comprised a sister group relationship to the Komarovieae of subfamily Apioideae. Except for Heptaptera, Keraymonia and Hymenolaena, all other genera within this clade are not monophyletic, with the type species of some genera(e.g. Physospermopsis, Pimpinella and Trachydium etc.)falling into other major clades of Apioideae. Therefore, the traditional circumscription between genera has been broken, which will bring a series of nomenclatural transfers. As the East-Asia Clade includes some medicinally important plants, to establish a set of standard identification system suitable for it will greatly promote the healthy development of traditional Chinese medicine industry, and provide guidance for folk safe medication. Furthermore, questions to be solved in its future study are also discussed.