Chao Yi-Shan, Rouhan Germinal, Amoroso Victor B, Chiou Wen-Liang
The Experimental Forest, National Taiwan University, Nantou, Taiwan Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.
Muséum national d'Histoire naturelle, UMR CNRS 7205, Herbier National, 16 rue Buffon CP39, 75005 Paris, France.
Ann Bot. 2014 Jul;114(1):109-24. doi: 10.1093/aob/mcu086. Epub 2014 Jun 7.
Pteris (Pteridaceae), comprising over 250 species, had been thought to be a monophyletic genus until the three monotypic genera Neurocallis, Ochropteris and Platyzoma were included. However, the relationships between the type species of the genus Pteris, P. longifolia, and other species are still unknown. Furthermore, several infrageneric morphological classifications have been proposed, but are debated. To date, no worldwide phylogenetic hypothesis has been proposed for the genus, and no comprehensive biogeographical history of Pteris, crucial to understanding its cosmopolitan distribution, has been presented.
A molecular phylogeny of Pteris is presented for 135 species, based on cpDNA rbcL and matK and using maximum parsimony, maximum likelihood and Bayesian inference approaches. The inferred phylogeny was used to assess the biogeographical history of Pteris and to reconstruct the evolution of one ecological and four morphological characters commonly used for infrageneric classifications.
The monophyly of Pteris remains uncertain, especially regarding the relationship of Pteris with Actiniopteris + Onychium and Platyzoma. Pteris comprises 11 clades supported by combinations of ecological and morphological character states, but none of the characters used in previous classifications were found to be exclusive synapomorphies. The results indicate that Pteris diversified around 47 million years ago, and when species colonized new geographical areas they generated new lineages, which are associated with morphological character transitions.
This first phylogeny of Pteris on a global scale and including more than half of the diversity of the genus should contribute to a new, more reliable infrageneric classification of Pteris, based not only on a few morphological characters but also on ecological traits and geographical distribution. The inferred biogeographical history highlights long-distance dispersal as a major process shaping the worldwide distribution of the species. Colonization of different niches was followed by subsequent morphological diversification. Dispersal events followed by allopatric and parapatric speciation contribute to the species diversity of Pteris.
凤尾蕨属（凤尾蕨科）包含250多个物种，在Neurocallis、Ochropteris和Platyzoma这三个单型属被纳入之前，一直被认为是一个单系类群。然而，凤尾蕨属的模式种长叶凤尾蕨与其他物种之间的关系仍不清楚。此外，已经提出了几种属内形态分类，但存在争议。迄今为止，尚未提出该属的全球系统发育假说，也没有呈现出对理解其世界性分布至关重要的凤尾蕨属全面生物地理历史。
基于叶绿体DNA的rbcL和matK基因，并使用最大简约法、最大似然法和贝叶斯推断方法，构建了135个凤尾蕨物种的分子系统发育树。推断出的系统发育树用于评估凤尾蕨属的生物地理历史，并重建通常用于属内分类的一个生态特征和四个形态特征的演化。
凤尾蕨属的单系性仍不确定，特别是凤尾蕨属与团扇蕨属+金粉蕨属以及Platyzoma之间的关系。凤尾蕨属包括11个分支，由生态和形态特征状态的组合支持，但在先前分类中使用的特征均未被发现是唯一的共衍征。结果表明，凤尾蕨属在约4700万年前开始分化，当物种殖民新的地理区域时，它们产生了新的谱系，这与形态特征转变相关。
这是首次在全球范围内对凤尾蕨属进行系统发育研究，涵盖了该属一半以上的多样性，应有助于基于生态特征、地理分布以及少数形态特征建立一个新的、更可靠的凤尾蕨属内分类。推断出的生物地理历史突出了远距离扩散是塑造该属世界性分布的主要过程。不同生态位的定殖之后是随后的形态多样化。扩散事件之后是异域和邻域物种形成，这有助于凤尾蕨属的物种多样性。
