Polyploidy

Polyploidy, the possession of more than two complete sets of chromosomes is one of the most important evolutionary pathways in flowering plants. A polyploidisation event confers immediate reproductive isolation from the parents and consequently bolsters sympatric speciation. Previous studies have revealed an overall tendency for low-ploid ancestral species to occur in southern European Pleistocene refugia such as the Balkan Peninsula, whereas higher-ploid derivatives are widespread further north. It is obvious that only detailed knowledge of the often rare and sometimes endangered ancestral species allows understanding of their polyploid offspring. The possibility of large-scale ploidy screening with flow cytometry together with the application of molecular techniques offer unprecedented possibilities to unravel the complex history of polyploid complexes.