Utilization of Rapd Markers for Determining Genetic Diversity in Sugar Beet

This study aimed to evaluate the effectiveness of RAPD (Random Amplified Polymorphic DNA) markers in determining the genetic diversity among 18 sugar beet (Beta vulgaris L. subsp. vulgaris) genotypes. Of the 11 RAPD primers initially tested, 6 primers showing the highest level of polymorphism were selected and analyses were performed across all genotypes. A total of 49 bands were obtained, 40 of which were identified as polymorphic, corresponding to a polymorphism level of 81.6%. As a result of the RAPD analyses applied, it was determined that there were significant levels of genetic differences among the genotypes. To visualize genetic relationships, UPGMA cluster analysis based on the Jaccard similarity coefficient and Principal Component Analysis (PCA) were performed. Diversity parameters such as the effective number of alleles, gene diversity, and Shannon’s diversity index as well as Nei’s genetic distance were calculated using POPGENE version 1.32 software. In terms of PIC, the highest values were found in OPA-18 (0.30) and OPA-2 / OPA-5 (0.29), while the lowest PIC value was observed in OPA-3 (0.20). The pairwise genetic distance matrix was obtained using MVSP 3.22 software, while the Q-matrix bar plot was generated with STRUCTURE software. The results of the analyses showed that genetically similar genotypes clustered together, whereas distinct genotypes were separated. In particular, the differentiation of SB-2 as the most genetically distant individual revealed that this genotype has the potential to increase genetic variation in breeding programs. In contrast, SB-10 and SB-12 genotypes exhibited high genetic similarity. The fact that commercial cultivars were distributed in different clusters demonstrated that these materials have different genetic origins and may share common alleles with gene bank accessions. The findings obtained revealed that RAPD markers are a reliable method for the characterization of sugar beet genetic resources and provide important information for parent selection and sustainable breeding strategies.