Genome size constancy in Antarctic populations ofColobanthus quitensisandDeschampsia antarctica

Colobanthus quitensis(Kunth) Bartl. andDeschampsia antarcticaDesv., the only two native flowering plants in the Antarctica, are interesting study cases from the ecological, biogeographic, and evolutionary points of view. Here, we present the first genome size analysis focused in several populations from the Antarctic Peninsula and the surrounding islands for both species, with a broad sampling distributed along a distance of 800 km. We have used flow cytometry to estimate genome size, being the first time that this technique is used forD. antarctica.Average genome sizes forD. antarctica(2C = 10.63 pg) andC. quintesis(2C = 2.01 pg) are consistent with the scarce previous data available, and point to a diploid and tetraploid ploidy level, respectively, for the analysed taxa. Despite a certain deviating individual inD. antarctica, whose higher genome size could suggest the existence of B-chromosomes, no significant genome size differences were found amongst the populations studied, for both species, which might be related with the recent colonisation history of the Antarctic continent.