Genetic Diversity of Major Olive Varieties from Southern Tunisia

Considering the importance of olive-growing in Tunisia, microsatellite (SSR) analysis was used to study the genetic variation among twenty olive accessions from southern Tunisia. This set of olive microsatellites showed potential utility for genetic studies and it could contribute to the development of strategies for Tunisian germplasm conservation and breeding. Unweighted pair group method cluster analysis was performed and cultivars separated in three main groups. Five polymorphic simple sequence repeats (SSR) loci were employed and they revealed 38 alleles with a mean number of 7.6 alleles per locus. Genetic variability was wide as indicated by high values of both observed heterozygosity (mean value = 0.79) and PIC values (average value = 0.60). Cultivars formed 3 distinct and clear groups. Var. ‘Chemlali’ was grouped with the others cultivars and showed low genetic diversity. We hypothesize that this variety is a population of cultivated varieties, with the presence of different clones of the same cultivar.