Genetic similarity among genotypes of sugarcane estimated by SSR and coefficient of parentage

The aim of this study was to analyze the genetic similarity in commercial cultivars of sugarcane from the breeding program cultivars RB (Republic of Brazil), using SSR markers and coefficient of parentage. Eighteen microsatellite markers were used to estimate genetic similarity in 30 genotypes and coefficient of parentage was estimated in 28 accessions. Eighteen primer pairs produced an average of 3.2 alleles, the level of polymorphism (PIC value) ranged from 0.34 to 0.78 in SMC248CG and SCC2 primers, respectively. The parentage coefficient was high among cultivars, with a mean of 0.14, suggesting high relationship among the cultivars. The results here suggest that to analyzed accessions, there is a high genetic similarity which could reduce the genetic gain in breeding. However, crosses among genotypes of sugarcane produce a high variability in the progenies, suggesting a combination between the genomes of species that originated the current cultivars.