菝葜科基于形态学证据的系统发育分析

对全世界范围分布的菝葜科Smilacaceae的79个代表种(包括了全部的属和组), 以分布于南美洲的Philesia Comm. ex Juss.和Lapageria Ruiz &; Pav.属为外类群, 选取包括花粉和染色体性状在内的47个广义的形态学性状进行了分支分类系统发育分析, 同时以表征分类的方法构建了距离树(NJ)辅助分析, 首次对世界分布的菝葜科各属间及属内的系统发育关系作了探讨。(1)Ripogonum与菝葜属Smilax +肖菝葜属Heterosmilax互为姐妹群, 但是距离较远, 支持将类菝葜属(新拟中文名)Ripogonum独立为科的观点; (2)肖菝葜属在菝葜科内处于较为进化的分支上, 并与菝葜属土茯苓组sect. Coilanthus的部分种组成一个具较高支持率(88%)的单系分支, 分析表明肖菝葜属并非是一个好属, 应归入菝葜属; (3)菝葜属6个组的划分大都没有得到支持, 只有东亚北美间断分布的草本菝葜组sect. Nemexia的单系得到很好的支持(93%); (4)分布于南美洲巴西的种类聚为一个单系类群, 表明它们可能有共同的起源, 但由于取样局限, 南美洲种类的系统地位有待进一步研究。

A phylogenetic analysis of the Smilacaceae based on morphological data

In order to construct phylogenetic relationships of the family Smilacaceae, 79 species representing all genera and sections of the family from all over the world were used for cladistic analysis, with Philesia and Lapageria of Philasiaceae as outgroups. A matrix of 36 binary and 11 multistate morphological characters was constructed. The first parsimonious analysis yielded numerous most parsimonious trees of 275 steps, and then 82 most parsimonious trees with 40.729 steps length were produced by reweighting characters using maximum values of rescaled consistency (RC), which remained stable after the second reweighting. There is a moderate resolution but generally poor bootstrap support for the phylogenetic relationships in the family. From the strict MP tree and the NJ tree, Ripogonum is a sister to Smilax, but may be better treated as a separate family. Heterosmilax is considered to be derived from ancestral Smilax and occurs as the most derived clade of the Smilacaceae, and thus it is reasonable to retain it as a section in Smilax s.l. Within Smilax most currently recognized sections are polyphyletic, but some major lineages are distinct. The herbaceous Smilax species form a monophyletic clade, and it is also the case for the South American species. Their positions in the cladogram are intriguing and may help to shed light on evolutionary and biogeographic history of the family.