东南亚地区五加科植物进化关系的初步研究(英文)

Evolutionary Relationships of Araliaceae in the Malesian Region:a Preliminary Analysis

东南亚五加科包含14个属约500种,本文应用ITS片段对该区五加科植物的进化关系作了初步研究。研究显示该地区五加科植物具有复杂的起源,很多属属于亚洲掌状复叶类群或Hedereae族的一支中。该区特有类群Harmsiopanax形态上非常特殊,但其系统位置尚未不明朗。在Brassaiopsis属中,有几种形态差异较大的种,但它们属同一单系,加之各种间ITS序列差异较小,故应是新近起源于马来亚半岛和苏门达腊岛的种类。Wardenia simplex聚类在Brassaiopsis一支中,故不支持将Wardenia作为独立的属。东南亚地区对于Schefflera属的发育非常重要,已有的证据显示该区的Schefflera属植物属于该属的Heptapleurum类群。马来亚与泰国南部的Dendropanax lancifolius并没有与Dendropanax属的核心类群聚在一起,其系统地位需进一步研究。Macropanax maingayi是非常特殊的一个种,曾被独立分出,成立了单种属Hederopsis。本文的分析清楚表明它属于Macropanax属。Aralia merrillii因为其不同寻常的攀缘特性而被独立出来,建立了单种属Acanthophora,但ITS序列分析支持将它置于Aralia属中。新增的取样继续支持Arthrophyllum的单系性。Os-moxylon的原初分布范围在东南亚,它是五加科系统进化树上孤立的类群。

We employ the nuclear ribosomal ITS sequences to assess the evolutionary relationships of Araliaceae in the Malesian region. Malesian Araliaceae consist of 14 genera and about 500 species. Our analysis suggests a diffuse origin of Araliaceae taxa, with many genera belong to the Asian palmate clade or the tribe Hedereae. The Malesian endemic Harmsiopanax is morphologically unique and its phylogenetic position is not well resolved at present. Several morphologically diverse species of Brassaiopsis perhaps have a relatively recent origin in the Malay Peninsula and Sumatra, as suggested by their monophyly as well as their low ITS sequence divergence. Wardenia is not supported as W. simplex （ = B. simplex） is nested within Brassaiopsis. The Malayan region is important for the development of Scheffiera, and available evidence suggests that Schefflera in the region forms a clade with the Heptapleurum group. Dendropanax lancifolius does not form a clade with the core group of Dendropanax, and its status needs to be further analyzed. Macropanax maingayi was considered to be a highly distinct member comprising the monotypic genus Hederopsis. Our analysis clearly places it in Macropanax. Aralia merrillii was once considered to be the sole member of the genus Acanthophora because of its unusual climbing habit. The ITS data support its placement in Ara!ia. Our expanded sampling of Arthrophyllum continues to support its monophyly. Osmoxylon has a primary distribution in the Malesian region and it is a hylogenetically isolated member of Araliaceae.