Study of the inheritance of agronomic characters using line × tester crosses in sunflower (Helianthus annuus L.)

Determining general and specific combining ability of lines is necessary to use them as parents of hybrid varieties. In addition, estimates of the heritability of characters helps in selecting suitable breeding methods and predicting genetic gains of the traits. To determine general and specific combining abilities and gene effects of agronomic characters, five CMS lines and four restorer lines (tester) were crossed in a line × tester scheme. Hybrids were evaluated using a randomized complete block design with three replications. The results showed that CMS lines 52, 330, 344 and testers R25 and R50 had high general combiners for seed and oil yield. Hybrids R25 × 222 and ­R23 × 52 also showed high specific combining ability for seed and oil yield. For head dry weight, seed weight per head, seed yield with hull, seed yield, oil percentage and oil yield, non-additive genetic effects were important. Plant height and seed number per head were controlled by both additive and dominance effects.