phylogeographic study of the Biscutella laevigata species complex

The Biscutella laevigata species complex encompasses diploid and tetraploid lineages. The distribution of diploids in never-glaciated lowlands suggests that they were pushed out of the Alps during the Pleistocene, whereas tetraploids found at high-elevation in previously-glaciated areas were formed at this time and recolonized the whole Alps after the last glacial maximum (LGM). However, areas where the different lineages survived the LGM remain unclear, as is the role of hybridization between distinct diploids or the single vs multiple origin of tetraploids. We extensively sampled 17 diploid populations from all around the Alps and 19 tetraploid populations across the central Alps and gentyped 370 individuals using ddRAD-seq.