Genetic diversity analysis among advanced breeding lines in pearl millet for grain iron, zinc and agronomic traits
Evaluation of genetic diversity within breeding populations will help in parents’ diversification and identification of trait-specific inbred sources. Total of 294 inbreds were evaluated for grain iron (Fe), zinc (Zn) and agronomic traits in two contrasting seasons using alpha-lattice field design. There was a significant variability observed for all traits. Three-to-four-fold variability noticed for Fe (31-120 mg kg-1), Zn (19-88 mg kg-1), yield (0.6-2.6 tha-1) and 1000- grain weight (6-16 g 1000-1). The magnitude of genetic coefficient of variation explained by traits were varied in the order of Fe (25%)>Zn>TGW>PL>PH>GY>PG>DF (7%) and heritability (broad sense) was very high as >84% for all traits except grain yield (56%). Nine clusters formed at 90% genetic similarity. Clusters I to IV and VII had higher mean value for Fe density (78-100 mg kg-1) and agronomic traits. Highest number of genotypes grouped in cluster I (63) followed by cluster III (54) having higher yield,1000-grain weight, panicle girth, Fe and Zn. Top-10% of high-Fe lines had significantly higher Fe (64%), Zn (49%), grainweight (29%) and panicle girth (19%) than bottom-10% genotypes. This implies that high-Fe/Zn sources are available with eliteness and can be incorporated into any genetic background without compromising agronomic superiority. Higher heritability and genetic advance as percentage of mean were observed for Fe, Zn and grain-weight suggesting these traits are predominantly determined by additive gene and can be improved through selection.