Genetics diversity in West African pearl millet landraces as revealed by simple sequence repeats (SSRS) molecular markers

Abstract

Pearl millet (Pennisetum glaucum [L.] R. Br.) is one of the most important staple food crops in the world, particularly in arid and semi-arid regions. In West Africa, pearl millet covers more than 65% of the total cultivated area. However, genetic diversity of this important crop in West Africa is poorly documented, although it is important for identification of landmarks for in situ germplasm conservation and to increase knowledge useful for breeding programs, particularly in heterotic studies. The overall aim of this study was therefore to understand the patterns of diversity within and among populations in order to enhance those populations with continuous genetic variation for association and heterotic studies. Genetic relationships and diversity among and within 30 pearl millet accessions from West Africa was assessed using twenty one Short Sequence Repeats (SSRs) markers. The markers revealed 172 alleles among 30 populations and 171 alleles within 10 populations, with the Polymorphic Information Content (PIC) ranging from 0.39 to 0.82. The mean Nei's genetic diversity across all the 21 loci in the 30 populations was 0.647 while the mean Nei's diversity within the 10 populations studied ranged from 0.402 to 0.835 with an average of 0.681. The partitioning of variance components based on the analysis of molecular variance (AMOVA) for diversity analysis revealed high variability within accessions (84.59%) compared to the variability between accessions (9.56%). The fixation index (Fst) obtained was 0.154 indicating a moderate differentiation among the accessions. This study estimated genetic diversity in a highly cross-pollinated crop-pearl millet and generated data on genetic diversity of 30 accessions from west African that could be used to select potential heterotic groups that can be exploited in breeding programs to increase hybrid vigour.