Evolutionary history of Origanum majorana L.

The genus Origanum comprises several well-known aromatic and medicinal plants that are predominantly distributed in the Eastern Mediterranean area. Due to their essential oils, Origanum species have been locally collected for centuries, for culinary and for various medicinal purposes. Today, large quantities of oregano (mainly wild collected O. vulgare and O. onites) and marjoram (mainly from cultivated O. majorana) are commercially traded and widely used all over the world. Origanum majorana marjoram is among the commercially most important Origanum species. The popularity of marjoram is mainly due to the exceptional composition of its essential oil whose very specific sensorial quality is clearly distinguishable from the typical oregano aroma exhibited by the majority of Origanum species. The genetic basis of the specific aromatic quality of marjoram has remained cryptic. Similarly obscure is the evolutionary history of O. majorana. Today, the wildtype of O. majorana is solely distributed in Cyprus, its temporal and biogeographic origin as well as its relationships to the most closely related Origanum species have yet not been satisfactorily clarified. Correspondingly, not much is known about the when and how of marjoram domestication. The main aims of this project are to assess the cryptic evolutionary origin of O. majorana and to clarify its relationships to the most closely related Origanum species and, closely associated to this aim, to trace evolution and genetic background of the distinctive marjoram aroma. Furthermore, we will explore the cultivation history and phenotypic specialties of cultivated O. majorana. To address these topics a broad sample including O. majorana (wildtype and cultivars) and closely related Origanum species will be collected and comparatively analysed with respect to certain morphological, genetic, and chemical characteristics. The enhanced knowledge of inter- and intraspecific variation of certain characteristics will serve as sound basis for an adapted species concept of O. majorana and a better knowledge about the origin of its phenotypic (chemotypic) specialties. Additionally, new insights into e. g. plant migration movements in the Mediterranean area, natural species diversity or plant domestication can be expected.