Data from: Phylogenetic relationships in Senegalia (Leguminosae-Mimosoideae) emphasizing the South American lineages

Senegalia is a genus of the legume family (Leguminosae: Mimosoideae) that has a pantropical distribution with centers of diversity in Brazil, Mexico and southern Africa. The genus is characterized by plants having bipinnate leaves, presence of petiolar nectaries, prickles on the branches, and pollen grains arranged in polyads with 16 grains. Morphology is an important tool for identification of Senegalia species, but it is not sufficient to resolve all taxonomic issues and elucidate the evolutionary history of this genus. Prior molecular analyses of Mimosoideae have lacked breadth of sampling within Senegalia, leaving many relationships uncertain, particularly the relationship among Brazilian species and other members of the genus. The aim of this study was to identify Senegalia s. s. lineages that contain Brazilian species, and to investigate the relationship of these species with non-Brazilian Senegalia species. We present the first comprehensively sampled phylogeny of American and African Senegalia, however Asian species are not sampled. We sequenced four plastid and one nuclear DNA (ITS) regions for 125 samples of 59 Senegalia and one Parasenegalia species. Both Bayesian and maximum likelihood analyses were performed. Neither the American or African species form monophyletic lineages. The lack of monophyly of these groups suggests a more complicated evolutionary history of the genus than previously considered, including probable transatlantic dispersal events.

金合欢属（Senegalia）是豆科（Leguminosae）含羞草亚科（Mimosoideae）下的一个属，呈泛热带分布，多样性中心位于巴西、墨西哥与非洲南部。该属植物具有二回羽状复叶（bipinnate leaves）、叶柄蜜腺（petiolar nectaries），枝条具皮刺，且花粉粒以16粒为一组的复合花粉块（polyads）形式排列。形态学是鉴定金合欢属（Senegalia）物种的重要手段，但不足以解决所有分类学问题，亦无法阐明该属的演化历史。此前针对含羞草亚科的分子分析，在金合欢属内的取样广度不足，导致诸多类群间的系统关系尚不明确，尤其是巴西物种与该属其他成员之间的亲缘关系。本研究旨在明确包含巴西物种的狭义金合欢属（Senegalia s. s.）支系，并探究这些物种与非巴西金合欢属物种之间的亲缘关系。本研究首次对美洲与非洲的金合欢属类群开展了全面取样的系统发育分析，但未涵盖亚洲物种。我们对59个金合欢属物种及1个副金合欢属（Parasenegalia）物种的125份样本，进行了4个质体DNA（plastid DNA）区域与1个核DNA内转录间隔区（Internal Transcribed Spacer，简称ITS）区域的测序，并同时开展了贝叶斯推断与最大似然分析。研究结果显示，美洲与非洲的金合欢物种均未形成单系支系（monophyletic lineages）。此类群缺乏单系性的结果表明，该属的演化历史比此前所认为的更为复杂，其中大概率存在跨大西洋的散布事件。