芍药属牡丹组基于形态学证据的系统发育关系分析

对芍药属牡丹组Paeonia L.sect.Moutan DC.（全部野生种）40个居群进行了基于形态学证据的系统学分析，试图建立组内种间的系统发育关系。利用PAUP （4.0）计算机程序分别构建了建立在25个形态学性状基础上的所有研究类群的距离树（UPGMA、NJ）和最大简约树（MP）。所得树的拓扑结构基本一致，差异只发生在距离树和简约树之间，在由形态和细胞学关系都很近的5个种（牡丹P.suffruticosa、矮牡丹P.jishanensis、卵叶牡丹P.qiui、紫斑牡丹P.rockii和凤丹P.o

Phylogenetic analyses of Paeonia section Moutan (tree peonies, Paeoniaceae) based on morphological data

Cladistic analysis of the morphological relationship of 40 populations of Paeonia sect. Moutan DC. (including all wild species) was carried out with an attempt to have a better understanding of the phylogeny of tree peonies. Twenty-five morphological characters were selected and used in unweighted pair-group method using arithmetic averages (UPGMA), the neighbor-joining (NJ) and the maximum parsimony (MP) tree construction executed with PAUP * program. The topologies of the trees obtained were largely in congruence and topological differences occurred only between MP tree and the other two in a clade comprising five species, P. suffruticosa, P. jishanensis, P. qiui, P. rockii and P. ostii, which were considered as closely related species based on both morphological and cytological characters. In both NJ and UPGMA trees, all the populations of each species formed a monophyletic clade, and the clades of P. ludlowii, P. qiui and P. decomposita had strong bootstrap supports (>90%), the clades of P. rockii , P. delavayi had moderate bootstrap supports (>70%), and the clades of P. suffruticosa , P. ostii and P. jishanensis had weak bootstrap supports (51%-70%). In MP tree, however, the corresponding bootstrap values of all the clades mentioned above were generally smaller than those in NJ and UPGMA trees and the populations of P. delavayi , P. ostii and P. suffruticosa failed to form monophyletic clades. Based on the above results, interspecific relationships of wild tree peonies were discussed and a phylogeny of sect. Moutan was reconstructed for the first time.