HERITABILITY ANALYSIS FOR SEED YIELD AND YIELD RELATED COMPONENTS IN SUNFLOWER (HELIANTHUS ANNUUS L.) BASED ON GENETIC DIFFERENCE

The present study was conducted to develop sunflower hybrids with maximum yield potential. The genetically diverse sunflower (Helianthus annuus L.) inbred lines comprising 6 cytoplasmic male steriles (CMS) and 6 fertility restorers (R-f were crossed in line x tester mating design and 36F(1) hybrids were obtained. The hybrids were evaluated during spring of 2003-2004 and 2004-2005 years for seed yield and yield components. The yield components included in the study were head diameter, 1000-seed weight, yield per hectare, harvest index, moisture factor and leaf area. A low to high level of genetic variability existed among the hybrids for all characters as revealed by analysis of variance. For the years 2004-2005, the highest heterotic value for yield per hectare was observed for cross combination, CMS-H55-2-2-1 x C-206R. While for 2004-2005 year, it was recorded for CMS-303 x RHA-271. The yield performance of hybrids was evaluated on the basis of genetic distance between the two parental lines. For yield and yield components, the greatest genetic distance revealed by Euclidean dissimilarity coefficient in the years 2003-2004 and 2004-2005 was observed for CMS-HAR-I x RHA-854 and CMS-64 x C-206R hybrids, respectivelly. This shows the existence of maximum genetic variability in these hybrids for seed yield and yield components. This study can be utilized in varietals improvement programme through heterosis breeding.