Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Buenos Aires , Argentina.
AoB Plants. 2010;2010:plq018. doi: 10.1093/aobpla/plq018. Epub 2010 Oct 19.
Macroptilium is a herbaceous legume genus with 18 currently accepted species, seven of them with economic importance due to their use as forage, green fertilizer and in medicine. The genus is strictly American, with an unknown biogeographic history. The aim of this study was to infer a biogeographic pattern of Macroptilium and to estimate its divergence times, using sequences from the nuclear ribosomal DNA internal transcribed spacers.
To study the historical biogeography of Macroptilium, two approaches were used: area optimization on a previously obtained phylogeny and a dispersal-vicariance analysis. Divergence times were calculated by Bayesian methods.
The analyses revealed that Macroptilium has its origin in the middle Pliocene, with an estimated age that ranges from 2.9 to 4 million years. The biogeographic analyses placed its origin in South America, specifically on the Chaquean sub-region, where most of the cladogenetic events of the genus took place.
Macroptilium constitutes a further example of the geographic pattern displayed by numerous Neotropical taxa that moved north from South America to dominate the Central American lowlands after the land connection across the Isthmus of Panama was established.
Macroptilium 是一种草本豆科植物属，目前有 18 个被接受的物种，其中有 7 个因其作为饲料、绿肥和药物的用途而具有经济重要性。该属是严格的美洲属，其生物地理历史未知。本研究的目的是推断 Macroptilium 的生物地理模式，并使用核核糖体 DNA 内转录间隔区的序列估计其分歧时间。
为了研究 Macroptilium 的历史生物地理学，采用了两种方法：在先前获得的系统发育树上进行区域优化和扩散-分歧分析。贝叶斯方法用于计算分歧时间。
分析表明，Macroptilium 的起源于中新世中期，估计年龄范围在 290 万至 400 万年之间。生物地理分析将其起源定位于南美洲，特别是在 Chaquean 分区，该属的大多数分支事件都发生在那里。
Macroptilium 是众多新热带分类群表现出的地理模式的又一个例子，这些分类群在巴拿马地峡建立陆地连接后，从南美洲向北移动，主导中美洲低地。
