The evolutionary history of Hypericum perforatum L.

• Antragsteller: Professor Dr. Marcus Koch
• Fachliche Zuordnung: Evolution und Systematik der Pflanzen und Pilze
• Förderung: Förderung von 2007 bis 2012
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 40137571

The genus Hypericum is a morphologically and ecologically highly diverged and large group of more than 460 species. Several species are wide-spread in Eurasia and dominate in lowland habitats not affected by extreme environmental factors. Hypericum perforatum and H. maculatum are representative examples with a largely overlapping distribution area, but the first one tends to prefer drier habitats, while the second species is distributed even in boreal Eurasian regions. We aim to unravel the evolutionary history of these two wide-spread lowland species during the pleistocene (phylogeography) and to characterize genetical contact zones reflecting actual and past geneflow between both. We would like to test if this evolutionary scenario of the wide-spread lowland species confirm patterns of refuge areas and principle migration routes revealed from the analysis of woody plants, annuals, arcticalpine representatives and others.It is very likey that hybridization and reticulation played a role in the evolution of different morpho- and cytotypes in H. perforatum as well as in H. maculatum, and it is also obvious, that there is ongoing geneflow between both species groups. This project is embedded in a larger research network focusing on the evolution and systematics of Hypericum in general, but selecting H. perforatum and closest relatives as model to focus on evolutionary important traits and characters. The results from this study are a prerequisite to discuss the evolution of one important trait in Hypericum, namely apomixis, the propagation via seeds produced without sexuality. This study will provide fundamental information about 1) centres of genetic diversity, 2) migration routes and source areas of genetic variation, 3) hybridization and suture zones, and 4) temporal estimates of diversification. All these information can be linked with the trait apomixis within populations actually analysed in detail and should answer questions about 1) multiple origin and constitution of apomixis (in space and time), 2) transmission of the trait via hybrid bridges, and 3) temporal dynamics of adaptation and transition from sexual to asexual propagation and wee versa.

• DFG-Verfahren: Sachbeihilfen