Genetic analysis suggests a shared origin of Punica granatum cultivars in Oman with cultivars from the center of origin, Iran

Pomegranate is important ancient fruit shrub in the Middle East, where it originated and has been cultivated for centuries. Oman, which lies between the two centers of origin of Punica spp. (Yemen and Iran), is known for cultivation of pomegranates. However, little is known about the relationship of pomegranates from Oman to pomegranates in Iran and Yemen. A study was conducted to investigate genetic diversity and relatedness among five cultivars of pomegranate from Oman with nine cultivars from Iran (5), Yemen (1), India (1), Lebanon (1) and Spain (1). A total of 88 pomegranate samples representing 14 cultivars (2-15 samples/cultivar) were analyzed using Amplified Fragment Length Polymorphism. The analysis produced 889 polymorphic loci and 88 genotypes. Omani, Yemeni and some Iranian cultivars clustered together, providing evidence for a relationship of clustering with geographical origin. AMOVA analysis indicated the existence of moderate and significant levels of genetic differentiation among all pomegranate cultivars (F-ST = 0.133), which indicates moderate level of cultivar exchange among countries. However, AMOVA analysis and Nei genetic similarity levels provided evidence that one cultivar each from Oman, Iran and Yemen, one from Oman and Iran and one from India and Spain were found to have a high level of genetic similarity. This suggests that these cultivars may have a common origin and have been moved among these countries via trade routes in the past. The findings are discussed in terms of factors affecting diversity of pomegranate.