Simple Sequence Repeats-Based Genetic Characterization and Varietal Identification of Potato Varieties Grown in Pakistan

The potato (Solanum tuberosum L.) is an important cash crop with a complex genome and with features of aneuploidy with a high level of heterozygosity. It is a prerequisite for potato breeding to have knowledge of genetic diversity and population structure. To understand the genetic characteristics of potato cultivars in Pakistan, 25 potato varieties were characterized with simple sequence repeat (SSR) markers to distinguish closely related varieties. In total, 214 alleles were amplified with 35 SSR markers exhibiting 89.2% polymorphism. The maximum number of alleles and polymorphic alleles per locus were 20 and 14 for the markers S25 and S174, respectively. The polymorphic information content (PIC) extended from 0.00-0.87. The size of the amplified PCR product ranged between (30-1000 bp). A cluster analysis divided the 25 varieties into three clusters: cluster I revealed the most diversity, followed by cluster II with 11 varieties and cluster III with 13 varieties. Nei's genetic diversity and minimum spanning network (MSN) depicted the Mozika variety as the most diverse compared to the rest of the varieties. Nei's coefficient was found to vary from 0.53 to 0.95. Out of the 25 studied varieties, 16 were uniquely identified by 29 polymorphic SSR bands of different sizes with a maximum size amplified by S4026/4027 (800bp) and a minimum by S170 (90bp). The genetic diversity and varietal identification determined in the present study has molecular and breeding-related significance with respect to the utilization and protection of intellectual property rights of potato cultivars for sustainable potato production in Pakistan.