Molecular characterization of pearl millet [Pennisetum glaucum (L.) R. Br] inbreds using microsatellite markers

Abstract

Studies on genetic diversity in Pennisetum germplasm are the promising opportunities for the use of un-domesticated materials for improving pearl millet varieties. DNA based markers have now emerged as a potential genomic tool for estimation of genetic diversity among various cultivars and varietal identification. In present study, genetic diversity among 49 stay green inbreds of pearl millet was studied using simple sequence repeats (SSRs). Twenty nine polymorphic SSR primers, identified after initial screening of 70, were used to study diversity among these lines. A total of 108 alleles were amplified, collectively yielding unique SSR profiles for all the 49 inbreds. The average number of SSR alleles per locus was 3.72, with a range from 2 to 13. Polymorphic information content (PIC) values of various SSR loci across all the 49 inbreds ranged from 0.14 to 0.87 with an average of 0.51 per lo-cus. This indicated sufficient diversity among the 49 pearl millet inbreds and total 5 out of 29 polymorphic SSR loci, namely Xpsmp2070, Xpsmp2001, Xpsmp2008, Xpsmp2066, Xpsmp2072 revealed PIC values above 0.70, can be considered highly useful for differentiation of pearl millet inbred lines. The lowest PIC value (0.47) for linkage group 7 showed comparatively conserved nature of this linkage group A dendrogram obtained using WARD’s minimum variance method further delineates 49 inbreds into 8 major clusters, and the clustering pattern corroborated with their pedigree and characteristics traits.