ABSTRACT

Sunflower (Helianthus annuus L.) a cross-pollinated crop, occupies a strategic position in food security as an important edible oilseed crop globally, due to its adaptability, short growth cycle (85–100 days), high yield potential, and photoperiodic insensitivity. The present study aims to introduce new inbreds resulting from mutation breeding, as well as the hybridization of B and R lines with TX-16R (Texas Red 16), to enhance the yield quality of hybrids by providing resistance to major biotic stresses. A line × tester mating design, with four CMS lines and twelve testers, was employed, resulting in 48 hybrids during Rabi 2023. The parents, hybrids, along with three checks, were assessed for general combining ability (GCA), specific combining ability (SCA) and heterosis using a Randomized Complete Block Design (RCBD) with two replications during Summer 2024. The analysis of variance revealed significant differences for most traits, indicating the diversity and potential of the parent lines used. The study found that SCA variance was higher than GCA variance for all traits, suggesting that non-additive gene action was predominant. CMS-17A and CMS-103A emerged as the best general combiners among the female parents, while DSR-35 was the top general combiner among the testers for seed yield and disease resistance, followed by DSR- 125, DSR-107, and PGS-3-1. SCA is a good predictor of per se performance. The hybrids CMS-17A × PGS-2-1, CMS-103A × DSR-37, and CMS-335A × PGS-3-1 were identified as
good specific combiners for multiple important traits, including seed yield per plant and oil content. Heterosis analysis showed significant positive effects for seed yield, with CMS-234A
× DSR-35 and CMS-17A × PGS-2-1 demonstrating high heterosis over the mid-parent and standard checks. Additionally, several hybrids exhibited resistance to Alternaria leaf blight, with CMS-17A × DSR-107, CMS-17A × PGS-2-1, and CMS-234A × DSR-35 identified as
resistant and high-yielding.