Variability and divergence studies on rice genotypes for micronutrient potential and its utility in biofortification

Abstract

Rice is the staple food crop for more than half of the world population. Thus, rice varieties enriched with various micronutrients qualifies as a better alternative to combat micronutrient deficiency. The present investigation was undertaken to study the variability, heritability and genetic divergence for grain characters especially grain Zinc (Zn) content and grain Iron (Fe) content in 30 genotypes of rice. Among the 30 genotypes that were under investigation, the Phenotypic Coefficient of Variation (PCV) values were found to be higher than that of Genotypic Coefficient of Variation (GCV) values for all the traits. High heritability (>60%) was observed for all the studied traits. Days to 50% flowering showed highest heritability (99.1%) followed by test weight (94.8%) and grain Fe content (94.8%). The genetic advance as percent of mean ranged between medium (10%-20%) to high (>20%) with grain yield per plant showing the highest GAM (40.84%) followed by test weight (38.56%) and grain Zn content (33.73%). These 30 genotypes were assigned into groups of 11 clusters using Tocher’s method. Cluster I comprised of the most number of genotypes with 18 genotypes followed by Cluster V with 3 genotypes while the remaining 9 clusters were monogenotypic. Days to 50% flowering was found to have the highest contribution towards genetic divergence. These findings indicated that the genotypes under study have sufficient trait variability and varietal diversity which could be exploited in crop improvement programmes aimed at developing Zinc (Zn) and Iron (Fe) biofortified varieties.