Systematics of subtribe Gentianinae (Gentianaceae)

以下列植物自然生境立即干燥的叶片为样品提取总DNA：斑纹细叶、藻龙胆、经典龙胆、罗丹花、云南龙胆、大龙胆、雷公藤、赤萼龙胆、日本龙胆、日本龙胆、长针叶龙胆。本研究最初打算分析rbcL或matK基因，但实际分析的是18S-25S核糖体DNA的ITS区域。总DNA提取、总ITS区扩增、PCR产物克隆、ITS区测序在东京都大学牧野标本室进行。测序时，使用新购买的ALFexpress （Pharmacia）自动测序仪。利用PAUP 3.0软件对得到的序列进行分析，构建了最简约的系统发育树。得到了一个由32棵等节俭树组成的一致树。该树的拓扑结构与目前对属间关系的认识基本一致，只有龙胆属Stenogyne部分与雷公藤属（Tripterospermum）和克罗佛属（Crawfurdia）以84%的自举概率连接成一个单系分支，这表明目前界域下的龙胆属不是一个单系类群。龙胆属、雷公藤属、雷公藤属中常见的三瓣种子可能是它们的一个近形。弯雄蕊可能与三棱种子同时获得，但在克劳弗底亚中消失。雷公藤属植物与克劳馥属植物合并为一个单系进化枝，而缠绕茎可能是它们的一个突触形态。有浆果的树种的单系性没有得到显著支持。

Leaf samples immediately dried at the natural habitat of following species were used as samples to extract total DNA : Crawfurdia maculaticaulis, Gentiana algida, G.classicauris, G.rhodantha, G.yunnanense, Gentianopsis grandis, Tripterospermum distylum, T.hirticalyx, T.japonicum, T.japonicum var. involubile, T.lanceolatum. At the initial stage of this study rbcL or matK gene was intended to analyze but actually the inter transcribed spacer (ITS) regions of 18S-25S nuclear ribosomal DNA was analyzed. The extraction of total DNA,amplification of total ITS region, clcaning of the PCR products, sequencing of ITS region were carried out in the laboratory of Makino Herbarium, Tokyo Metropolitan University. For sequencing, the autosequensor ALFexpress (Pharmacia) , newly purchesed by this grant, was used. The sequences obtained were analyzed with PAUP 3.0s to construct the most parsimonious phylogenetic trees. As a result a consensus tree of the 32 equally parsimonious trees was obtained. The tree topology is generally conglueut with corrent understanding of the relationships between genera, excepting that Gentiana section Stenogyne joined to form a monophyletic clade with Tripterospermum and Crawfurdia with bootstrap probabilities 84%, which suggests that the genus Gentiana under present circumscription is not a monophyletic group. The triquetrous seeds commonly found in Gentiana section Stenogyne, Tripterospermum and Crawfurdiathe may be a synapomorphy of them. The recurved stamens might be gaind at the same time as triquetrous seeds but disappeared in Crawfurdia. Tripterospermum and Crawfurdia joined a monophyletic clade and the twining stem may be a synapomorphy of them. The monophyly of the species with berries was not significantly supported.