伞形科囊瓣芹属的表型分析

选取伞形科(Apiaceae)囊瓣芹属(Pternopetalum Franchet)32个分类群的60个形态学性状,利用DELTA系统的UPGMA算法进行了聚类分析。结果表明属下形成以五匹青(P.vulgare(Dunn)Hand.-Mazz.)和东亚囊瓣(P.tanakae(Franchet&Sav.)Hand.-Mazz.)为代表的两个主要表征群。两个主要表征群的分类结构和各自所包含的类群基本相应于前人研究中本属两个组的属下处理。根据全面相似性分析的结果和部分形态学特征的评估,确认了属下6个种的复合群:即五匹青、囊瓣芹(P.davidii Franchet)、散血芹(P.botrychioides(Dunn)Hand.-Mazz.)、洱源囊瓣芹(P.molle(Franchet)Hand.-Mazz.)、澜沧囊瓣芹(P.de-lavayi(Franchet)Hand.-Mazz.)和东亚囊瓣芹复合群。根据形态学特征在表型树上的分布分析表明:伞形花序的着生位置、花柱的形态、花柱基的形状和萼齿的大小等生殖特征可能是属下早期分化的关键性性状。属下主要变异类型(种的复合群和典型狭域特有种)对不同海拔区域和小生境的依赖,以及不显著的形态学分化表明:对横断山区较高的异质性生境的生态适应是囊瓣芹属类群多样化过程后期的一个重要特征。

Phenetic Analysis of the Genus Pternopetalum (Apiaceae)

Phenetic analysis was conducted for 32 taxa of Pternopetalum Franchet(Apiaceae)by using UPGMA algorithm implemented in DELTA packages,based on 60 morphological characters.The results were shown that the 32 taxa were grouped into two distinct phenetic groups,which was represented by P.vulgare and P.tanakae,respectively.The taxonomic structure of two groups and taxa included in each of them are consistent with section division made by previous researches.Six species complexes,P.vulgar,P.davidii,P.botrychioides,P.molle,P.delavayi and P.tanakae complex,were identified on the basis of phenetic relationships and evaluation of morphological variation.Mapping of character state on phenogram revealed that attached position of umbels,morphology of styles,stylopodium and calyx teeth,were possible key characters responsible for earlier morphological divergence in Pternopetalum.Ecological adaptation to heterogeneous habitats in Mt.Hengduan regions was shown to be characteristics of latter species diversification of Pternopetalum,which was evidenced by differentiated habitat and elevation favor,and combined with indistinct morphological divergence in major species complexes.