Polyploidisation and geographic differentiation drive diversification in a European High Mountain Plant Group (Doronicum clusii Aggregate, Asteraceae).

摘要: Range shifts (especially during the Pleistocene), polyploidisation and hybridization are major factors affecting high-mountain biodiversity. A good system to study their role in European high mountains is Doronicum clusii aggregate (Asteraceae), whose four taxa (D. s.s., D. stiriacum, glaciale subsp. calcareum) differentiated geographically, ecologically (basiphilous versus silicicolous) and/or via ploidy levels (diploid tetraploid). Here, we use DNA sequences (three plastid one nuclear spacer) AFLP fingerprinting data generated for 58 populations infer phylogenetic relationships, origin of polyploids—whose level was confirmed by chromosomally calibrated estimates—and phylogeographic history. Taxonomic conclusions were informed, among others, a Gaussian clustering method species delimitation using dominant multilocus data. Based on molecular identified three lineages: (i) silicicolous diploid s.s. Alps, (ii) tetraploid stiriacum eastern Alps (outside range s.s.) Carpathians (iii) basiphilous diploids (eastern Alps) calcareum (northeastern Alps); each taxon as distinct clustering, but separation not stable, supporting taxonomic treatment subspecies. Carpathian Alpine genetically suggesting phases vicariance, probably Pleistocene. The (autopolyploid allopolyploid) remained unclear. morphologically weakly separated from exhibited significantly higher genetic diversity rarity. This suggests that more widespread originated calcareum, which restricted prominent Pleistocene refugium previously other alpine plant species.