Hybrid zones, or zones of genetic admixture of different intraspecific cytotypes, provide clues to evolutionary transitions and the mechanisms of polyploid speciation. Čertner et al. present insights into the spatio-temporal dynamics of diploid – polyploid contact zones.
A combination of flow cytometry and large-scale field sampling enables comparison of cytotype diversity across spatial and temporal scales and ontogenetic stages in the common annual herb Tripleurospermum inodorum (Asteraceae). Temporal changes in ploidy composition were detected at within-population and landscape scales. Widespread coexistence of diploids and tetraploids in Central Europe enables inter-ploidy mating and leads to striking variation in DNA content among offspring. The study highlights the dynamic nature of contact zones and their high potential to generate cytogenetic novelty.
This paper is part of the Annals of Botany Special Issue on Polyploidy in Ecology and Evolution. It will be free access until October 2017, then available only to subscribers until August 2018 when it will be free access again.