Identification and Evaluation of Genetic Diversity among Potato Cultivars Using Microsatellite Markers

The identification of potato cultivars is a recurrent objective of potato research. The research is prompted by the increasing number of potato cultivars and the importance of seed purity. In developing a reliable method for identification of the imported potato cultivars and determining their genetic relationship, the capacity of 10 polymorphic simple sequence repeat markers (SSRs) was evaluated for the analysis of 28 commercial cultivars of potato. The number of alleles detected at different loci ranged from 3 to 10 alleles with a total of 57 for all loci and a mean of 5.7 alleles per locus. In the 28 potato cultivars analyzed, the number of heterozygous genotypes per locus varied between 6 to 28 with an average number of heterozygous genotypes per locus of 18, considering the 10 loci studied. Based on the resulting dendrogram of jacquard's similarity coefficient and UPGMA analysis, the potato cultivars were placed in two major groups. However, the results from similarity coefficient confirmed the close phylogenetic relationships among members in each cluster. The dendrogram derived from SSRs data clustered together Kenebek, Florida and Atlantic which are known as American potato cultivars, but Stanbuli, an old cultivar in Iran, was placed in concert with European cultivars. This finding might be an indication that this cultivar along with other unidentified cultivars, growing in local fields, has been introduced from European countries to Iran. The results obtained illustrate the appropriate utility of SSRs to assess genetic relationships of potato cultivars and develop a PCR- based tool for evaluation of potato seed purity.