Assessment of Genetic Relationship among Some Iraqi Walnut Genotypes(Juglans regia L.) in Sulaimani Region Using RAPD and SSR Molecular Markers

Juglans regia L. is cultivated for both nuts and timber in Hawraman region in Iraq. To clarify the genetic variability in walnuts grown in this region, twelve walnut genotypes of diverse origins were analyzed with 10 selected Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeat (SSR) markers. RAPD primers produced 85 bands, out of which 36 were polymorphic ranging from 2 to 7 with an average of 3.6 per primer. The genotypes shared 42.35% of polymorphic bands. In SSR analysis, nine primers gave 26 bands, out of which 23 were polymorphic ranging from 2 to 5 with an average of 2.3 per primer. SSR primers shared 88.16% of polymorphic bands. Genetic similarities were calculated and ranged from 0.4 to 0.93 for RAPD data and 0.27 to 1.00 for SSR data. Cluster analysis by RAPD and SSR markers revealed clear distinct diversity between genotypes. The dendrogram realized from the RAPD and SSR markers grouped the 12 genotypes into four major clusters. Wazi and Kirmashan1 were closely related for RAPD or SSR data. Twana and Awesar revealed the highest dissimilarity as compared with the others genotypes. Combination of RAPD and SSR data shared that Twana showed the highest dissimilarity comparing with all other genotypes. A wide range of genomic diversity was observed among all genotypes, making them candidates for selective breeding for specific traits and broadening the genetic base. Based on these results, RAPD and SSR analysis can be used for the characterization and grouping of walnut genotypes.