Data from: Pervasive introgression during rapid diversification of the European mountain genus Soldanella (L.) (Primulaceae)

Hybridization is a key mechanism involved in lineage diversification and
speciation, especially in ecosystems that experienced repeated
environmental oscillations. Recently radiated plant groups, which have
evolved in mountain ecosystems impacted by historical climate change
provide an excellent model system for studying the impact of gene flow on
speciation. We combined organellar (whole plastome) and nuclear genomic
data (RAD-seq) with a cytogenetic approach (rDNA FISH) to investigate the
effects of hybridization and introgression on evolution and speciation in
the genus Soldanella (snowbells, Primulaceae). Pervasive introgression has
already occurred among ancestral lineages of snowbells and has persisted
throughout the entire evolutionary history of the genus, regardless of the
ecology, cytotype, or distribution range size of the affected species. The
highest extent of introgression has been detected in the Carpathian
species, which is also reflected in their extensive karyotype variation.
Introgression occurred even between species with dysploid and euploid
cytotypes, which were considered to be reproductively isolated. The
magnitude of introgression detected in snowbells is unprecedented in other
mountain genera of the European Alpine System investigated hitherto. Our
study stresses the prominent evolutionary role of hybridization in
facilitating speciation and diversification on the one hand, but also
enriching previously isolated genetic pools.