UMR 7138 Systématique, Adaptation, Evolution, Département Systématique et Evolution, Muséum National d'Histoire Naturelle, CP 39, 75231 Paris cedex 05, France.
Mol Phylogenet Evol. 2011 Dec;61(3):697-713. doi: 10.1016/j.ympev.2011.07.019. Epub 2011 Aug 9.
Systematics of the red algal order Corallinales has a long and convoluted history. In the present study, molecular approaches were used to assess the phylogenetic relationships based on the analyses of two datasets: a large dataset of SSU sequences including mainly sequences from GenBank; and a combined dataset including four molecular markers (two nuclear: SSU, LSU; one plastidial: psbA; and one mitochondrial: COI). Phylogenetic analyses of both datasets re-affirmed the monophyly of the Corallinales as well as the two families (Corallinaceae and Hapalidiaceae) currently recognized within the order. Three of the four subfamilies of the Corallinaceae (Corallinoideae, Lithophylloideae, Metagoniolithoideae) were also resolved as a monophyletic lineage whereas members of the Mastophoroideae were resolved as four distinct lineages. We therefore propose to restrict the Mastophoroideae to the genera Mastophora, Metamastophora, and possibly Lithoporella in the aim of rendering this subfamily monophyletic. In addition, our phylogenies resolved the genus Hydrolithon in two unrelated lineages, one containing the generitype Hydrolithon reinboldii and the second containing Hydrolithon onkodes, which used to be the generitype of the now defunct genus Porolithon. We therefore propose to resurrect the genus Porolithon for the second lineage encompassing those species with primarily monomerous thalli, and trichocyte arrangements in large pustulate horizontal rows. Moreover, our phylogenetic analyses revealed the presence of cryptic diversity in several taxa, shedding light on the need for further studies to better circumscribe species frontiers within the diverse order Corallinales, especially in the genera Mesophyllum and Neogoniolithon.
红藻纲珊瑚藻目的系统发育历史悠久而复杂。本研究采用分子方法，基于两个数据集的分析来评估系统发育关系：一个包含主要来自 GenBank 序列的 SSU 序列的大型数据集；以及一个包含四个分子标记（两个核：SSU、 LSU；一个质体：psbA；和一个线粒体：COI）的组合数据集。两个数据集的系统发育分析均证实了珊瑚藻目的单系性，以及该目中目前公认的两个科（珊瑚藻科和 Hapalidiaceae）。珊瑚藻科的四个亚科（Corallinoideae、Lithophylloideae、Metagoniolithoideae）中的三个也被解析为一个单系谱系，而 Mastophoroideae 的成员则被解析为四个不同的谱系。因此，我们建议将 Mastophoroideae 仅限于 Mastophora、Metamastophora 和可能的 Lithoporella 属，以达到使该亚科单系的目的。此外，我们的系统发育分析将 Hydrolithon 属解析为两个不相关的谱系，一个包含模式种 Hydrolithon reinboldii，另一个包含 Hydrolithon onkodes，后者曾是现已灭绝的 Porolithon 属的模式种。因此，我们建议为第二个谱系恢复 Porolithon 属，该谱系包含主要为单体的藻体和大疱状水平行中 Trichocyte 排列的物种。此外，我们的系统发育分析揭示了几个类群中存在隐种多样性，这表明需要进一步研究以更好地划定珊瑚藻目这一多样性目中的物种边界，特别是在 Mesophyllum 和 Neogoniolithon 属中。
