Analysis of genetic diversity of some olive cultivars olea europoea l. using issr, ssr

Abstract

Background: To conserve the germplasm, identify different varieties and optimize breeding programs, molecular characterization of olive (Olea europaea L.) cultivars is necessary. Inter-simple sequence repeat (ISSR) and simple sequence repeat (SSR) markers are complementary methods in determining genetic diversity and phylogenetic relationships among varieties of olive.

Objective: To establish the genetic relationships and diversity of seven olive cultivars in terms of ISSR and SSR molecular markers.

Methods: DNA was extracted in leaf samples of seven olive cultivars, giving a concentration of between 150-400 µg with purity ratios of between 1.6-1.9. Agarose gel electrophoresis was used to confirm the quality of the DNA. Four primers of the ISSR (UBC-817, UBC-826 and two others) were used and five primers were used to characterize the genomes genetically. Bands polymorphism, unique bands and lack of bands were documented. Calculation of genetic similarity and distance was done and dendrogram clustering was carried out to evaluate phylogenetic groupings.

Results: ISSR analysis produced a total of 93 bands, out of which 91 were polymorphic and 2 monomorphic, with 4 distinct bands and 7 missing bands identified. The highest molecular size band (1500 bp) was produced by primer UBC-817; the lowest (200 bp) by UBC-826. Suranie and Frantoio cultivars had the shortest genetic distance (0.030), whereas Frantoio and Santacatrina had the highest genetic distance (0.622). Dendrogram analysis showed three larger clusters, and the second cluster was further divided into two subgroups (B1 and B2). Genetic similarity patterns were established through SSR analysis with four out of five effective primers and were consistent with ISSR data.

Conclusion: The ISSR and SSR markers were effective in measuring genetic diversity among seven olive cultivars and they are complementary in establishing phylogenetic relationships and in enabling the use of cultivar differentiation to manage olive germplasm.