Genetic Diversity and Variation Among Olive Genotypes Revealed by AFLP, SSR and SNP Marker

Olive (Olea europeae L.) is one of the most ancient and important cultivated plant in the Mediterranean area, where it is the most important oil-producing crop. DNA marker technology represents an easy and accurate cultivar identification methods for search and elucidation of homonyms, synonyms and unknown accessions throughout the rich olive collections. Combining use of different markers to assess the genetic diversity is more precise in terms of realibility, when used only one type of marker. The study focuses on the molecular characterization of 96 genotypes originating from different regions of Turkey based on the AFLP, SSR and SNP marker techniques. AFLP yielded 919 polymorphic products using 26 primer combinations. A total of 62 alleles were detected by fourteen SSR primers, with an average of 4.4 alleles per primer. The 49 SNP markers yielded 89 alleles with an average polymorphic bands of 1.8 per primer. A total of 1070 polymorphic bands were generated. The polymorphism information content (PIC) values ranged from 0.15 (OPC15) to 0.89 (GAPU90). Genetic variation ranged from 0.14 to 0.69. The genetic relationships among genotypes were investigated using cluster analysis and principal component analysis (PCA). Our results show evidence of clustering of olive genotypes according to their geographic origin. A combination of different markers was finally proposed that can be used accurately for cultivar identification.