THE ROLE OF IRAN (PERSIA) IN APPLE (MALUS × DOMESTICA BORKH.) DOMESTICATION, EVOLUTION AND MIGRATION VIA THE SILK TRADE ROUTE

Abstract

To shed light on the role of Iran in apple evolution and domestication, the relationships among a collection of 159 apple accessions including indigenous Iranian apple cultivars and landraces, selected wild species, and old apple scion and rootstock cultivars from different parts of the world were investigated. The accessions were assigned into six arbitrary populations for the purpose of generating information on genetic parameters and these were screened with nine simple sequence repeat (SSR) loci selected from previous studies in apple. The SSR allelic data were then used to determine the population structure using SRUCTURE 2.2 software and genetic relationships based on a phenogram constructed using POPGENE 1.32 software. The results showed good agreement between the population structure data and the phenogram, and demonstrated that Iranian cultivars and landraces have a closer genetic affinity with Malus sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia, than with other Malus species. Also, old apple scion and rootstock cultivars were closely related to one another and grouped between M. sieversii/M. orientalis and the rest of the wild Malus species. The closer genetic and geographic affinity of the Iranian germplasm with M. sieversii and M. orientalis, together with their location on the Silk Trade Route, suggests that Iran could be one of the major hubs in apple domestication and transfer from Central Asia to the West via the Silk Trade Route. We propose that Iran could be a main center of diversity for domestic apples.