Role of genome duplication in changing mountain landscapes

Many plants have more than two sets of chromosomes in their body cells; they are called "polyploid". A recent global analysis of chromosome numbers has shown that the frequency of polyploid plants increases with latitude, i.e. with increasing distance from the equator. Much less is known about the distribution of polyploid plants in mountainous regions, for example along the altitudinal gradient. In temperate mountain regions, the frequency of polyploids could, on the one hand, increase towards higher habitats (due to their higher stress tolerance) and, on the other hand, increase with increasing distance from glacial refugia (due to their better migratory ability).

With the help of flow cytometry, a method for quantifying the amount of DNA in the cell nucleus, we want to determine for several tens of thousands of individuals of flowering plants how many sets of chromosomes they possess. The samples will be collected in 100 altitudinal transects evenly distributed over the Eastern Alps. These transects extend from 550 m below to 550 m above the timberline. Using these data, we will investigate whether the frequency of polyploid plants increases with higher altitude and / or with greater distance from the nearest glacial refugium. Furthermore, we will test whether the ecological (climatic) niches differ between individuals of the same species that have a different number of chromosome sets. Using predictive modelling, we will also investigate whether the risk of extinction due to climate change is greater for individuals with low or high numbers of chromosome sets. This will allow us to estimate the extent of future plant biodiversity loss.

The proposed research represents an unprecedentedly broad empirical test at the landscape level of the long-standing hypothesis of a positive association between the occurrence of polyploidy and spatiotemporal environmental variation – and its change in times of severe environmental change. The project is led by Prof P. Schönswetter (University of Innsbruck, Austria) and carried out in cooperation with the national partners Prof Stefan Dullinger (University of Vienna, Austria), as well as the international cooperation partners Dr Filip Kolář (Charles University, Czech Republic) and Dr Petr Koutecký (University of South Bohemia, Czech Republic).