Discriminating the Capabilities and Efficiencies of RAPD, ISSR and SSR Markers in the Assessement of the Genetic Variation in Cultivated Tunisian Olives

The olive tree is a typical crop in the Mediterranean basin, where it shows wide genetic variability of the olive germplasm. Therefore, studying the genetic diversity to preserve and conserve local olive tree resources is a challenge. In this context, random amplified polymorphic DNA (RAPD), inter simple sequence repeat (ISSR) and simple sequence repeat (SSR) markers were used for detecting genetic variation among 13 Tunisian olive cultivars. The effectiveness of the three methods in generating their levels of information on olive genetic relationships and diversity was studied. Furthermore, the polymorphic information content (PIC), effective multiplex ratio (EMR), marker index (MI) and Shannon’s diversity index were calculated based on molecular data. The unweighted pair-group method with arithmetic averages (UPGMA) tree obtained from cluster analysis discriminated different major groups of olive genotypes. Bayesian analysis of the population structure for the combined primer data with K = 2 separated the 13 genotypes into two clusters. The RAPD method resulted in 45 bands, 38 of which were polymorphic (84