Universidade Federal do Rio Grande do Norte, Departamento de Botânica, Ecologia e Zoologia, Natal, Rio Grande do Norte, Brazil.
Mol Phylogenet Evol. 2012 Jul;64(1):177-89. doi: 10.1016/j.ympev.2012.03.015. Epub 2012 Apr 2.
The genus Alcantarea comprises near 30 species endemic to rocky outcrops from eastern Brazil. Most species are ornamental and several are threatened due to habitat loss and over collection. In this paper we examine the phylogenetics of Alcantarea and its relationship with the Brazilian members of Vriesea, a genus of which Alcantarea has been treated as a subgenus. We discuss the morphological evolution of the stamen position and its implication for pollination and the occurrence of Alcantarea in the Espinhaço mountain range rocky savanna-like habitat vegetation. DNA sequence data derived from two plastid markers (trnK-rps16, trnC-petN) and from a low copy nuclear gene (Floricaula/Leafy) together with 20 nuclear microsatellite loci were the data source to perform analyses and construct phylogenetic and Neighbor Joining trees for the genus. Alcantarea is well supported as monophyletic in both Bayesian and parsimony analyses, but sections of Vriesea, represented by the eastern Brazilian species, appear paraphyletic. Microsatellites delimit geographically isolated species groups. Nevertheless individuals belonging to a single species may appear related to distinct clusters of species, suggesting that hybridization and/or homoplasy and/or incomplete lineage sorting are also influencing the analysis based on such markers and may be the reasons for some unexpected results. Alcantarea brasiliana is hypothesized as putative hybrid between A. imperialis and A. geniculata. Spreading stamens, a morphological floral characteristic assumed to be related to Chiropterophily, apparently evolved multiple times within the genus, and invasion of rocky savanna-like habitat vegetation by Atlantic rainforest ancestors seems to have occurred multiple times as well.
该属 Alcantarea 包含近 30 种特有于从巴西东部的岩石露头。大多数物种是观赏性的，有几个物种由于栖息地丧失和过度采集而受到威胁。在本文中，我们研究了 Alcantarea 的系统发育及其与巴西 Vriesea 成员的关系，Vriesea 属的 Alcantarea 被视为一个亚属。我们讨论了雄蕊位置的形态进化及其对传粉的影响，以及 Alcantarea 在埃斯皮尼亚山 rocky savanna-like 植被中的出现。来自两个质体标记物（trnK-rps16、trnC-petN）和一个低拷贝核基因（Floricaula/Leafy）的 DNA 序列数据以及 20 个核微卫星基因座是进行分析和构建系统发育和邻接树的数据源。Alcantarea 在贝叶斯和简约分析中都得到很好的支持，是单系的，但 Vriesea 的部分代表巴西东部的物种似乎是并系的。微卫星限定了地理隔离的物种群体。然而，属于单一物种的个体可能与不同的物种簇相关，这表明杂交和/或同功进化和/或不完全谱系分选也在影响基于此类标记物的分析，并且可能是一些意外结果的原因。Alcantarea brasiliana 被假设为 A. imperialis 和 A. geniculata 之间的可能杂种。伸展的雄蕊，一种假定与 Chiropterophily 有关的形态花特征，显然在属内多次进化，并且大西洋雨林祖先对 rocky savanna-like 植被的入侵似乎也多次发生。
