Disentangling relationships among the members of the Silene saxífraga alliance (Caryophyllaceae): Phylogenetic structure is geographically rather than taxonomically segregated

Abstract

Out of ca. 700 species belonging to Silene, 15 to 35 were classified in S. sect. Saxifragoideae. This section has its highest diversity on the Balkan Peninsula, which was the most important European Pleistocene refugium. The most widespread of the species is S. saxifraga ranging from the Pyrenees to the Carpathians. Together with ten morphologically similar taxa it is often treated as the S. saxifraga group, but the relationships among the taxa are unclear and blurred due to the occurrence of transitional forms. In this study, we used sequences of the nuclear ribosomal internal transcribed spacer (ITS) and the plastid rps16 intron as well as amplified fragment length polymorphisms (AFLPs) to elucidate phylogenetic relationships among the taxa belonging to—or hypothesized to be closely related to—S. sect. Saxifragoideae, covering the section’s entire geographical range. Phylogenetic analyses of 112 populations belonging to 33 taxa clarified previous classifications and showed that S. cephallenia, S. congesta, S. linoides, S. multicaulis, S. schwarzenbergeri and S. waldsteinii are clearly differentiated from all other taxa, which in turn form the newly circumscribed S. saxifraga group. Phylogenetic relationships within the latter are unresolved, and are governed by geographic proximity rather than by taxonomic identity. This is likely a result of recent rapid radiation and range expansion, as well as of convergent morphological evolution triggered by similar environmental selection pressures. The southern parts of the Balkan Peninsula are the centre of genetic diversity of the group, underlining the area’s importance as a sanctuary of diversification of European biota.

A new taxonomic backbone for the infrageneric classification of the species‐rich genus Silene (Caryophyllaceae)

“…Two accessions of S. falcata generated by Ðurović & al. () are nested within, and almost identical to, sequences of S . sect.…”

Allele Sorting as a Novel Approach to Resolving the Origin of Allotetraploids Using Hyb-Seq Data: A Case Study of the Balkan Mountain Endemic Cardamine barbaraeoides

“…Despite extensive botanical explorations and well-described endemism patterns in this area, speciation processes that have driven the evolution of the rich mountain flora are still not sufficiently explored. Mainly allopatric speciation often accompanied by reticulate and polyploid evolution has been suggested in recent studies ( López-Vinyallonga et al, 2015 ; Olšavská et al, 2016 ; Durović et al, 2017 ; Španiel et al, 2017 ). High species diversity in this area may also be connected with adjacent Anatolia, which is recognized as a center of lineage diversification in several plant genera and a possible source for the colonization of the Balkan Peninsula (e.g., Ansell et al, 2011 ; Surina et al, 2014 ; Caković et al, 2015 ; Koch et al, 2017 ).…”

So Closely Related and Yet So Different: Strong Contrasts Between the Evolutionary Histories of Species of the Cardamine pratensis Polyploid Complex in Central Europe

“…The great diversity and rarity observed currently in populations belonging to the Central lineage support the scenario of in situ glacial survival without major population displacement. In contrast to the studies listed above, however, populations of Central lineage did not spread significantly in postglacial times, which resembles the case of Silene hayekiana (Durović et al, 2017). The distribution of many species is evidently limited by slow postglacial spreading rather than by environmental limitations (e.g., Svenning and Skov, 2007;Willner et al, 2009;Baer and Maron, 2019).…”