Moiloa Ntwai A, Mesbah Melilia, Nylinder Stephan, Manning John, Forest Félix, de Boer Hugo J, Bacon Christine D, Oxelman Bengt
Department of Biological and Environmental Sciences, University of Gothenburg, Carl Skottsbergs Gata 22 B, 413 19 Gothenburg, Sweden; Gothenburg Global Biodiversity Centre, Box 461, 405 30 Gothenburg, Sweden.
Gothenburg Global Biodiversity Centre, Box 461, 405 30 Gothenburg, Sweden; Laboratory of Ecology and Environment, Faculty of Natural and Life Sciences, University of Bejaia, 06000 Bejaia, Algeria.
Mol Phylogenet Evol. 2021 Sep;162:107199. doi: 10.1016/j.ympev.2021.107199. Epub 2021 May 11.
Silene (Caryophyllaceae) is distributed predominantly in the northern Hemisphere, where it is most diverse around the Mediterranean Basin. The genus is also well represented in North Africa, extending into tropical, sub-Saharan and southern Africa. Eight native species are recognized in southern Africa, taxonomically placed in two sections: Elisanthe and Silene s.l. Although the taxonomy of the southern African taxa has recently been revised, their phylogenetic relationships and biogeographic history remain unclear. This study aims to infer the phylogenetic position and geographic origins of the southern African taxa. We generated DNA sequences of nuclear and plastid loci from several individuals belonging to all eight species of Silene recognized from southern Africa, and combined our DNA sequences with existing data representing species from major clades (i.e. sections) based on the recently revised Silene infrageneric taxonomy. We used a Bayesian coalescent species tree continuous diffusion approach to co-estimate the species tree and the ancestral areas of representative members of the genus. Our results show that the perennial southern African members of section Elisanthe form a strongly-supported clade with the Eurasian annual S. noctiflora and the Central Asian perennial S. turkestanica. The rest of the perennial species form a strongly-supported clade together with the annual S. aethiopica, which is nested in a larger Mediterranean clade comprising mostly annual species classified in section Silene s.l. Estimates of ancestral areas indicate a late Pleistocene dispersal to southern Africa from central and East Africa for the sub-Saharan members of section Silene s.l. The Elisanthe clade is inferred to have colonized southern Africa through long-distance dispersal from Eurasia during the late Pleistocene. Our findings support the hypothesis of a relatively recent colonization into southern Africa resulting from two independent dispersal events during the Pleistocene.
蝇子草属（石竹科）主要分布在北半球，在地中海盆地周围最为多样化。该属在北非也有很好的代表，并延伸到热带、撒哈拉以南和南部非洲。在南部非洲确认有8个本土物种，在分类学上分为两个组：Elisanthe组和广义的蝇子草组。尽管最近对南部非洲分类群的分类进行了修订，但其系统发育关系和生物地理历史仍不清楚。本研究旨在推断南部非洲分类群的系统发育位置和地理起源。我们从南部非洲确认的所有8种蝇子草的几个个体中生成了核基因座和质体基因座的DNA序列，并将我们的DNA序列与基于最近修订的蝇子草属内分类法的代表主要分支（即组）的物种的现有数据相结合。我们使用贝叶斯合并物种树连续扩散方法来共同估计物种树和该属代表性成员的祖先区域。我们的结果表明，Elisanthe组的多年生南部非洲成员与欧亚一年生植物夜花蝇子草和中亚多年生植物突厥蝇子草形成了一个得到有力支持的分支。其余的多年生物种与一年生植物埃塞俄比亚蝇子草一起形成了一个得到有力支持的分支，埃塞俄比亚蝇子草嵌套在一个更大的地中海分支中，该分支主要包括广义的蝇子草组中分类的一年生物种。祖先区域的估计表明，广义的蝇子草组的撒哈拉以南成员在晚更新世从非洲中部和东部扩散到南部非洲。推断Elisanthe分支在晚更新世通过从欧亚大陆的远距离扩散而在南部非洲定殖。我们的发现支持了一个假设，即更新世期间两次独立的扩散事件导致了相对较新的对南部非洲的定殖。
