HETEROTIC PERFORMANCE OF F1 HYBRIDS FOR PHENOLOGICAL, YIELD, OIL AND PROTEIN TRAITS OF SUNFLOWER

Abstract

The present study was conducted at Oil Seeds Section, Agriculture Research Institute, Tandojam, Pakistan. The crosses were attempted in line x tester mating design during 2008. Six cytoplasmic male sterile female lines i.e. ARG-0306, 64-A-93, PSF-025, SF-187, ARG-0405 and ARG-0505 and three testers, viz. RHP-46, RHP-64 and ARG-0106 were crossed in a line x tester mating design. Thus 18 F₁ hybrids were developed for evaluation of heterotic effects for days to 50% flowering, stem girth, head diameter, 1000-achene weight, seed yield kg ha^-1 and oil and protein contents during 2009. The experiment was conducted in a Randomized Complete Block Design (RCBD) with four replications. The analysis of variance revealed significant differences among genotypes, parents, F₁s and parents vs. hybrids for all these traits. The F₁ hybrids like ARG-0405 x RHP-46 expressed  maximum desirable  negative heterobeltiosis of -24.11% for days to 50% flowering;  64-A-93 x ARG-0106 explicated a maximum desirable better parent heterosis of 32.55% for stem girth; ARG-0505 x RHP-46 demonstrated a highest heterobeltiotic effects of 43.80% for head diameter; 64-A-93 x RHP-46 exhibited a maximum high-parent heterosis of 28.80% for 1000-seed weight, 32.87% for seed yield and 11.85% for oil content, and F₁ hybrid SF-187 x ARG-0105 manifested 42.86% heterobeltiosis for protein content. These hybrids therefore are suitable for hybrid crop development. Results further revealed that if two parents with good performance involved in crosses expressed high heterosis, that heterosis was due to additive genes, while if one good and one poor performing parent manifested high heterotic effects, that heterosis was due to complementary genes, and if both poor performing parents manifested high heterosis, such heterotic effects were due to dominant genes.