中国狸尾豆属及其近缘属的形态变异研究

Morphological variation of Uraria Desv. (Fabaceae)and its related genera in China

关键词:  豆科, 山蚂蝗族, 聚类分析, 主成分分析, 分类学意义

Key words:  Fabaceae, Desmodieae, cluster analysis, principal component analysis, taxonomic significance

摘要:

狸尾豆属(Uraria Desv.)及其近缘的蝙蝠草属(Christia Moench)和算珠豆属(Urariopsis Schindl.)的属间属内分类一直存在争议。为探究狸尾豆属及其近缘属的形态变异规律,并为其分类提供形态学数据,该文基于3属15种43个居群的296份标本,在居群水平上,对其叶片、花序、花、果实及种子的24个形态性状进行观察统计,并进行了均值分析、主成分分析和聚类分析。结果表明:(1)狸尾豆属与蝙蝠草属(台湾蝙蝠草除外)的属间界限清晰,叶长、顶生小叶长和宽、花萼在花后是否膨大是属间的重要分类特征,而其与算珠豆属的属间界限不清晰。(2)狸尾豆属的种间变异大,叶长、侧生小叶长、旗瓣长、花序类型和花序轴上的毛被类型可以作为种间的关键分类性状; 在蝙蝠草属中,叶长、托叶长、顶生小叶长和侧生小叶长具有重要的分类价值; 在算珠豆属中,花序长是种间关键分类性状。(3)在欧氏距离为16.5时,15个种聚为4支,其中美花狸尾豆和猫尾草各聚为1支,蝙蝠草属(台湾蝙蝠草除外)聚为1支,狸尾豆属、算珠豆属以及蝙蝠草属的台湾蝙蝠草共9个种聚为1支,支持将台湾蝙蝠草和算珠豆属归并入狸尾豆属中。该研究结果为狸尾豆属及其近缘属的分类和进化相关研究提供了形态学证据。

Abstract:

Intergeneric and intrageneric classifications of Uraria Desv. and its related genera(Christia Moench and Urariopsis Schindl.)have long been controversial. To explore the patterns of morphological variation and provide morphological data for the taxonomy of these genera, mean analysis, principal component analysis, and cluster analysis of 24 morphological traits based on 296 specimens from 43 populations(3 genera and 15 species)were conducted. The results were as follows:(1)The intergeneric boundary between Uraria and Christia (except Christia campanulata)was clear, and length of leaf, length and width of terminal leaflet, and whether the calyx enlarged after flowering period were valuable taxonomic traits between genera, while the boundary with Urariopsis was not clear.(2)Within Uraria, length of leaf, length of lateral leaflet and length of standard, types of inflorescence and hairs on rachis could be used as the key taxonomic traits; within Christia, length of leaf, length of stipule, length of terminal leaflet and length of lateral leaflet were of great taxonomic value; within Urariopsis, length of inflorescence was of great taxonomic trait.(3)At an Euclidean distance of 16.5, the 15 species were clustered into four clades, of which Uraria picta and U. crinita were clustered as two monophyletic clades, respectively. The genus Christia(except C. campanulata)was clustered into an monophyletic clade, and the other nine species of Uraria, Urariopsis, and Christia campanulata of the genus Christia were clustered into one clade. For taxa that were taxonomically controversial, our results supported that C. campanulata and Urariopsis should be attributed to the genus Uraria. The present study can provide a basis for the taxonomy and evolution of Uraria and its related genera.