Agromorphological and molecular analysis discloses wide genetic variability in sunflower breeding lines from USDA, USA

The present study investigates genetic divergence among 84 fertility restorers and 32 cytoplasmic male sterile (CMS) lines of sunflower augmented from USDA, USA along with the popular Indian parental lines using simple sequence repeats (SSR). Thirty-nine polymorphic SSR primers produced 139 alleles with an average of 3.56 alleles per locus. The polymorphic information content ranged from 0.23 to 0.69 with an average of 0.45. The average genetic distance was 0.45 and 0.42 for the R and CMS lines, respectively. Dendrogram based on the dissimilarity coefficient matrix grouped the CMS and R lines into separate clusters except for Cluster A which consisted of all CMS lines along with five R lines. Genetic distance matrix estimated from three sets of mitochondrial primers (BOX, ERIC and REP) grouped the 32 CMS lines into eight clusters. The results suggest the existence of considerable genetic diversity among the restorer and CMS lines of sunflower obtained from USDA, USA.