Genetic Variability and Association Analysis for Yield and Its Component Traits in Sunflower (Helianthus annuus L.)

Twenty-nine sunflower genotypes were evaluated for genetic variability and association of various morphological traits with seed yield. The genotypes were evaluated in Randomized Complete Block Design with three replications. Eight biometrical traits viz., days to 50% flowering, days to maturity, plant height (cm), head diameter (cm), volume weight (g/100 mL), 100-seed weight (g), oil content (%) and seed yield per plant (g) were recorded. The phenotypic and genotypic variation washigh for seed yield per plant and 100-seed weight, indicating that selection will be effective for improving these characters. Traits with high heritability and high genetic advance were highly amenable to selection which was observed for days to 50% flowering and plant height. The trait days to maturity weregoverned by non additive gene action as it showed low genetic advance. Correlation coefficients measure the degree of relationship between two or more variables. The key trait seed yield per plant had positive significant correlation with plant height (0.61), head diameter (0.83) and 100-seed weight (0.73). Path analysis revealed that 100-seed weight (0.62), days to maturity (0.34) and head diameter (0.30) had high positive direct effect on seed yield. Head diameter had the highest positive indirect effect on seed yield per plant through 100-seed weight (0.45)