RT Journal Article SR Electronic T1 Evidence of an additional center of apple domestication in Iran, with contributions from the Caucasian crab apple Malus orientalis JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.03.28.437401 DO 10.1101/2021.03.28.437401 A1 Bina Hamid A1 Yousefzadeh Hamed A1 Venon Anthony A1 Remoué Carine A1 Rousselet Agnès A1 Falque Matthieu A1 Shadab Faramarzi A1 Xilong Chen A1 Jarkyn Samanchina A1 David Gill A1 Akylai Kabaeva A1 Giraud Tatiana A1 Hossainpour Batool A1 Abdollahi Hamid A1 Gabrielyan Ivan A1 Nersesyan Anush A1 Cornille Amandine YR 2021 UL http://biorxiv.org/content/early/2021/08/30/2021.03.28.437401.abstract AB Anthropogenic and natural divergence processes in crop-wild fruit tree complexes are less studied than in annual crops, especially in the Caucasus, a pivotal region for plant domestication. We investigated anthropogenic and natural divergence processes in apples in the Caucasus using 26 microsatellite markers amplified in 550 wild and cultivated samples. We found two distinct cultivated populations in Iran, that were both genetically differentiated from Malus domestica, the standard cultivated apple worldwide. Coalescent-based inferences using approximate Bayesian computation showed that these two cultivated populations originated from specific domestication events in Iran. One of the Iranian clusters encompassed both cultivated and forest trees, suggesting that either farmers use of local wild apple for cultivation or that some forest trees represent feral cultivars. We found evidence of substantial wild-to-crop, crop-crop and crop-to-wild gene flow in the Caucasus, as has been previously described in apple in Europe and in fruit trees in general. In the Caucasus, we identified seven genetically differentiated populations of wild apple (Malus orientalis). Niche modeling combined with genetic diversity estimates indicated that these populations likely resulted from range changes during the last glaciation. This study identifies Iran as a key region in the evolution and domestication of apple and further demonstrates the role of wild-to-crop gene flow during fruit tree domestication. Our results support the view that domestication of fruit trees was likely a geographically diffuse and protracted process, involving multiple, geographically disparate, origins of domestication. We also highlight the impact of climate change on the natural divergence of a wild fruit tree and provides a base for apple conservation and breeding programs in the Caucasus.Competing Interest StatementThe authors have declared no competing interest.