Genetic diversity of Turkish olive varieties assessed by simple sequence repeat and sequence-related amplified polymorphism markers

Abstract

Olive (Olea europaea L.) is one of the most important and characteristic fruit crops of the Mediterranean region. This crop has been grown in Turkey for more than 3000 yr and many varieties are currently grown in five geographic regions. In this study, the genetic diversity of 66 olive varieties from these regions was assessed using simple sequence repeat (SSR) and sequence related amplified polymorphism (SRAP) markers. The 13 SSR markers yielded 89 alleles with an average polymorphism information content (PIC) of 0.29 and 6.8 alleles per marker while the 13 SRAP primer combinations generated 103 polymorphic alleles with an average PIC of 0.24 and 7.9 alleles per combination. Although SSR markers revealed higher levels of polymorphism than SRAP markers, both systems revealed considerable molecular genetic diversity in Turkish olive varieties. For both marker types, clustering analysis using the Dice similarity coefficient and the unweighted pair group method with arithmetic means (UPGMA) produced dendrograms with similar clustering and some region-specific grouping of varieties. Overall, Southeast Anatolian and Marmara varieties were found to be more genetically different than those from the other regions (Aegean, Mediterranean, and Black Sea) and homonymous varieties were identified: three pairs of varieties ('Egriburun', 'Celebi', and 'Tasarasi') had the same names but were genetically distinct. © Crop Science Society of America.