Development of polymorphic microsatellites markers using DNA sequences of chandler walnut cultivar

Juglans regia L. is the only commercially important species for its nuts in the genus. Simple sequence repeats (SSRs) have been used to construct genetic linkage maps in heterozygous plants. There is no adequate number of SSRs in the literature that can be used to construct a SSR based genetic linkage map in J. regia. In this study, 800 SSR primer pairs were designed from DNA sequences of Chandler walnut cultivar. Of 800 primer pairs, 551 (%68.9) SSRs were polymorphic, 88 (%11) did not produce bands, and 161 (%20.1) were monomorphic. A total of 551 polymorphic SSRs were used to characterize 16 walnut cultivars (Chandler, Franquette, Hartley, Fernor, Fernette, Serr, Pedro, Midland, Kaplan-86, Maraş-12, Sütyemez-1, Sütyemez-2, Şebin, Kaman-1, Yalova-1 ve Bilecik). A total of 2.696 alleles were produced by 551 polymorphic SSR loci in 16 walnut cultivars, ranging from 2 to 14 alleles per locus with an average number of 4.89. Polymorphism information content (PIC) ranged from 0.21 to 0.89 with an average of 0.62. According to phylogenetic analysis, local and foreign walnut cultivars were in two different groups. Genetic similarity index values were between 0.424-0.771. According to genetic similarity index values, Fernor and Franquette were the closest cultivars, while Kaman-1 and Fernor were the most distant. As a result, many polymorphic SSRs were developed in this study, and these markers will be useful in constructing genetic linkage maps, parental identification, genetic diversity and population genetic studies in walnut.