Identification of diversity pools of pearl millet [Pennisetum glaucum (L.) R. Br.] Restorer lines based on phenotypic and genotypic data

Pearl millet [Pennisetum glaucum (L.) R. Br.] is a nutri-cereal mainly grown as dual-purpose crop (fodder and grain). Hybrid breeding plays important role for enhancement of productivity in this crop. Variation present in restorer lines play crucial role for exploration of hybrid vigour in a three-line (A, B and R) system of hybrid development. Selection of parents based on F₁ performance is a time taking and laborious. However, clustering of genotypes based on phenotyping and genotyping can reduce efforts for selection of restorer lines. In present study, 32 pearl millet restorer lines were characterized phenotypically using 9 agro-morphological traits and molecular identification using 16 microsatellite markers. Based on morphological traits, genotypes were appeared into 6 clusters. In the genotyping, 33 alleles were obtained from 14 polymorphic loci of SSR marker with a mean of 2.36 alleles/marker. Polymorphic Information Content (PIC) was observed from 0.21 to 0.67 with the average of 0.38. In the genotyping based phylogenetic analysis, two major clusters were appeared. Population genetic structure analysis was also performed with varying number of K. In the ΔK study, peaks were observed at K = 2 and K = 4 which denoted the possible population structures and genotypes appearing provides opportunity for selection of true to types ancestry genotypes for hybrid breeding. Both the analysis grouped 15298 R, 18196 R, 15061 R, and 15611 R into different clusters depicting the presence of diversity among these genotypes which suggested they could be selected in further hybrid breeding programme depending upon the target of breeding for grain or fodder purpose.