Silene ciliata Pourr. (Caryophyllaceae) is a species with a highly disjunct distribution that inhabits the alpine mountains of the Mediterranean Basin. We investigated the phylogeny and phylogeography of the species in an attempt to a) clarify the long suggested division of S. ciliata into two subspecies, b) evaluate its phylogenetic origin and c) assess whether the species´ diversification patterns were affected by the Mediterranean relief. For this purpose, we collected DNA from 25 populations of the species that inhabit the mountains of Portugal, Spain, France, Italy, FYROM, Bulgaria and Greece and studied the plastid regions rbcL, rps16 and trnL. Major intraspecific variation was supported by all analyses, while the possibility of existence of more varieties or subspecies was not favoured. Plastid DNA evidence, especially in the cases of rps16 and trnL markers, was in accordance with the division of S. ciliata into the two subspecies, one spreading west (Iberian Peninsula and Central Massif) and the other east of the Alps region (Italian and Balkan Peninsula). The present study proposes that this vicariance has probably derived from the Alps acting as a barrier to the species dispersal. The monophyletic origin of the species is highly supported. Plastid DNA patterns may have resulted from a combination of geographic factors providing links and barriers, climatic adversities and evolutionary processes that took place during Quaternary glaciations. The latter might include hybridization events for the western subspecies and mutational accumulation for the eastern ones.
Taxonomic and Functional Diversity of a Quercus pyrenaica Willd. Rhizospheric Microbiome in the Mediterranean Mountains
