Phylogenetic diversity and relationships among sorghum accessions using SSRs and RAPDs

Abstract

Two DNA-based fingerprinting techniques, simple sequence repeats (SSR) and random amplified 
polymorphic DNA (RAPD) analyses, were applied in sorghum germplasm analysis to compare 
suitability for quantifying genetic diversity. Twenty-two sorghum genotypes, representing an array of 
germplasm sources with important agronomic traits, were assayed for polymorphism using 32 RAPD 
primers and 28 sets of sorghum SSR primers. The results indicated that SSR markers were highly 
polymorphic with an average of 4.5 alleles per primer. The RAPD primers were less polymorphic with 
nearly 40% of the fragments being monomorphic. An analysis of genetic diversity among sorghum lines 
indicated that the genetic distances calculated from SSR data were highly correlated with the distances 
based on the geographic origin and race classifications. Based on the results of these studies, SSR 
markers appear to be particularly useful for the estimation of genetic similarity among diverse 
genotypes of sorghum.