Investigating the origin of hazelnut (<Emphasis Type="Italic">Corylus avellana</Emphasis> L.) cultivars using chloroplast microsatellites

The place and time of European hazel (Corylus avellana L.) domestication is not clear, although it was already cultivated by the Romans. In this study, 75 accessions from Spain, Italy, Turkey, and Iran were analysed using 13 chloroplast microsatellite to investigate the origin and diffusion of hazelnut cultivars. Four loci were polymorphic and identified a total of four different chlorotypes. Their distribution was not uniform in each geographical group. The most frequent chlorotype A was present in all groups. An increase in chlorotype number and diversity from Spain eastward to Italy, Turkey, and Iran was observed. Results suggest that some spread of cultivars occurred from East to West and that hazelnut cultivation was not introduced from the eastern Mediterranean basin into Spain and southern Italy by Greeks or Arabs. Moreover, the results suggest considerable exchange of germplasm between Italy and Spain, probably by the Romans. Hazelnut appears to have been domesticated independently in three areas: the Mediterranean, Turkey, and Iran.