DOMESTICAZIONE DELL’OLIVO

The oleaster is considered the ancestor of the cultivated olive varieties, originating in Asia Minor which is the primary center of origin of the species. Plastid DNA allows the identification of three areas of genetic diversity of olive trees: the Levant, the Aegean and the Strait of Gibraltar, which have acted in the long term as refuge areas for the olive tree. The three Mediterranean lineages began during the Middle Pleistocene or Early Pleistocene, long before the last glacial peak. Sedentary human communities planted the first orchards (8,000-7,000 years BC) using olive genotypes selected on the basis above all of the larger fruits and the ease with which they could propagate vegetatively through cuttings and grafting. After the initial domestication in the eastern Mediterranean basin in the Aegean-Cretan area, which can be considered a center of secondary diversification, two independent events of domestication of the olive tree took place: one in the southern European area and one in the North-Africa which involved crossings with the present wild olive trees, and which together constitute the center of tertiary diversification of the olive tree.