Genome Size in the Species Complex (Caryophyllaceae), with Special Focus on Northern Europe and the Arctic.

The main aim of the present study has been the completion of genome size data for the diverse arctic-alpine species complex, with special focus on the unexplored arctic taxon , the north-European and from Gotland (Sweden). Altogether, 46 individuals of these three Nordic taxa have been sampled from seven different regions and their genome size estimated using flow cytometry. Three other alpine taxa in the complex (, subsp. , and subsp. ) were also collected and analyzed for standardization purposes, comprising 20 individuals from six regions. A mean 2c value of 1.65 pg of DNA was recorded for , 2.80 pg for , and 4.14 pg for as against the reconfirmed 2c value of 1.63 pg DNA for the type taxon subsp. . Our results presenting the first estimations of genome sizes for the newly sampled taxa, corroborate ploidy levels described in the available literature, with being tetraploid (2n = 4x = 40), possessing predominantly 2n = 8x = 80, and with 2n = 10x = 100. The present study also reconfirms genome size and ploidy level estimations published previously for the alpine members of this species complex. Reflecting a likely complex recent biogeographic history, the species group comprises a polyploid arctic-alpine species complex characterized by reticulate evolution, polyploidizations and hybridizations, probably associated with rapid latitudinal and altitudinal migrations in the Pleistocene-Holocene period.