Molecular characterization and genetic diversity analysis of mandarin genotypes by SSR and SRAP markers

The aim of the present study was to characterize the mandarin germplasm conserved at the Tuzcu Citrus Variety Collection at Cukurova University in Turkey using simple sequence repeat (SSR) and sequence-related amplified polymorphism (SRAP) based molecular approaches. Genetic characterization of 65 mandarins was performed using 14 SSR markers and 21 SRAP markers. We originally tested 26 SSR markers, and 14 of these markers were selected due to their high polymorphism information content in the molecular assays. Thirty-eight alleles were detected at 14 loci. The number of alleles per SSR locus ranged from 2 to 4, with a mean of 2.7 alleles. The most informative loci were CAGG 9, CAT 01 and TAA 52 (4 alleles/primer). From the SRAP analysis, a total of 187 alleles were generated, and the polymorphism rate was 77%. The number of alleles detected by a single primer set ranged from 4 to 15, with an average of 8.90. The UPGMA dendrogram, defined by SSR and SRAP markers, revealed the genetic relatedness of the mandarin genotypes. These findings can be used to guide future breeding studies and germplasm management of these mandarin genotypes.