Domestication bottleneck as a signature of history diffusion of apricot species
Résumé
Domestication generally implies a loss of diversity in crop species relative to their wild ancestors because of genetic drift through bottleneck effects. The comparison of genetic diversity in Mediterranean areas was assessed. 207 native apricot accessions representatives of the local variability from different Mediterranean countries: Algeria, France, Italy, Morocco, Spain, Tunisia and Turkey in each country were selected excluding those issued from breeding programs. This material was analysed for genetic diversity and structure using a common set of 25 monolocus microsatellites distributed throughout the Prunus genome. According to the geographic origin of the material and using a model‐based clustering method, four main gene pools were revealed, namely ‘Irano‐Caucasian’, ‘North Mediterranean Basin’, ‘South Mediterranean Basin’, and a more transversal one named ‘Adapted Diversity’. A significant gradient of decreasing diversity and allelic richness from the east to the south‐west of the Mediterranean Basin was highlighted. Overall, results suggested that from the Irano‐Caucasian area, apricot was introduced into the Mediterranean Basin through at least two different routes: the first one through the South of Europe and the second one through the North Africa. On the present bases relevant elements have been obtained useful for future management of apricot genetic resources as well as for genetic selection programs related to adaptive traits.