The Phylogenetic Position of Eastern Asian Sedoideae (Crassulaceae) Inferred from Chloroplast and Nuclear DNA Sequences

关于景天亚科的划分和分类仍存在较大分歧，属下分类成为景天科亟待解决的系统问题之一。关于该亚科的各种分类已被提出，并有两种截然相反的观点。一种观点保留了景天作为一个包罗万象的分类单元，仅承认景天亚科下的少数属；另一种观点根据独特的形态特征将景天属中的一些属(如红景天Rhodiola，HyloTelephium，Phedimus)从景天属中分离出来，并在亚科下识别出一些属。为了解决这些相互矛盾的观点，有必要检验从景天属分离出来的属的单系地位，并澄清它们与景天属(S，Str.)的系统发育关系。景天亚科植物约有300种，分布于东亚地区(Ohba 1978)，从景天属分离出来的大部分属仅限于东亚。此区域无法…我利用核糖体重复序列的cpDNA trnL-trnF间隔区和内部转录间隔区的序列变异，在东亚大范围内对菊科的系统发育进行了估计，以阐明亚洲菊科的系统发育位置。我们的结果与大多数前人的研究结果一致，除了Telephium分支。东亚所有属，除景天属(S，Str.)与Telephium分支对应的类群，该分支被确定为多系，具有4个强支持的亚支：红景天、HyloTelephium、Phedimus和Ubilicus。从Sedwnn分离的所有东亚属在与景天不同的谱系中分开(S。Str.)HyloTelephium、Orostachys、Meterostachys和Sincrassula关系密切。与Orostachys一样，HyloTelephium是多系植物。在这次讲座中，我们将介绍我们对昆贾的初步研究。较少

Opinions about the delimitation and classification of the subfamily Sedoideae are still highly divergent, and thus the generic and infrageneric classification becomes one of urgent systematic problems in Crassulaceae. Various classifications of the subfamily have been proposed and there are two opposing viewpoints. One view retains Sedum as a catchall taxon and recognizes only a few additional genera under the Sedoideae, and the other segregates some groups as genera (e.g., Rhodiola, Hylotelephium, Phedimus) from Sedum on the basis of unique sets of morphological characters and recognizes a number of genera under the subfamily. It is necessary to resolve these conflicting viewpoints by testing the monophyletic status of genera separated from Sedum and clarifying their phylogenetic relationships to Sedum (s. str.). About 300 species of Sedoideae are distributed in the eastern Asian region (Ohba 1978) and most genera segregated from Sedum are restricted in eastern Asia. This region can t … More herefore be regarded as both a center of generic and infrageneric diversification and a center of distribution for the Sedoideae.I estimated the phylogeny of the Sedoideae on a broad scale across eastern Asia using sequence variation of the cpDNA trnL-trnF spacer and the Internal Transcribed Spacer regions of the nuclear ribosomal repeats to clarify the phylogenetic positions of Asian Sedoideae. Our results agreed with most of the former studies, except for the Telephium clade. All eastern Asian genera except Sedum(s. str.) were in groups corresponding to the Telephium clade and the clade was determined to be polyphyletic with four strongly supported subclades, Rhodiola, Hylotelephium, Phedimus, and Umbilicus. All eastern Asian genera segregated from Sedwnare separated in a lineage distinct from Sedum (s. str.). Hylotelephium, Orostachys, Meterostachys, and Sinocrassula are closely related. Hylotelephium is polyphyletic, as is also Orostachys. In this lecture our preliminary study on Kungia will be introduced. Less