||The main topics of the proposed project are microevolutionary and speciation processes in diploid-polyploid complexes belonging to the Brassicaceae family. Speciation both at the diploid and polyploid levels will be examined, elucidating the role of genome merge and duplication, geographical and ecological separation. The questions addressed have broader relevance, beyond the studied genera, and the answers can help us better understand processes underlying polyploid speciation as such. The methods applied in this project will include both conventional molecular systematics markers, as well as methods based on the Next Generation Sequencing (NGS), namely restriction site associated DNA sequencing (RAD-seq) and combination of target enrichment of low-copy nuclear genes and genome skimming (Hyb-seq). Using the multi-marker approach we expect to gain deeper insights into the studied species complexes and increased robustness of the results. As a complement, flow-cytometric, morphometric, and ecological and climatic niche analyses will be employed. In order to achieve these goals we have chosen four genera from three different tribes of the Brassicaceae family (Alysseae [Alyssum, Odontarrhena], Camelineae [Arabidopsis], Cardamineae [Cardamine]), representing different evolutionary lineages in this family. We will take the advantage of the wealth of methods that are available for and already tested in the closely related genus Arabidopsis, our previous long-term experience with the proposed study genera, and also previously collected plant material.