Genome size variation and polyploidy incidence in the alpine flora from Spain

Abstract

The interest to study genome evolution, in particular genome size variation and polyploid incidence, has increased in recent years. Still, only a few studies have been focused at a community level. Of particular interest are high mountain species, because of the high frequency of narrow endemics and their higher susceptibility to extinction due to the effects of climate change. In the present study we explored genome size variation and polyploidy incidence in the entomophilous plant communities of two distinct mountain ranges, the Sierra Nevada and Picos de Europa National Parks. For that, chromosome numbers and DNA ploidies were assessed through a review of the literature, and the genome size and incidence of polyploidy in 39 taxa from several key genera were estimated using flow cytometry. In this study, first genome size estimations are given for 32 taxa. The majority of the analyzed taxa presented very small to small genome sizes (2C ≤ 7.0 pg), with no differences being detected between genome size and geographic origin and distribution ranges. A low incidence of polyploid taxa was observed (23.3%), with polyploids being more common in Picos de Europa than in Sierra Nevada. Most taxa inferred as polyploids were high altitude plants, but no clear pattern between polyploidy incidence and endemic status was observed. The obtained results are discussed within the context of angiosperm’s genome size variation and of polyploidy incidence in alpine and arctic flora, contributing to the scientific knowledge of these natural communities of great biological importance.