Gene effects and combining abilities of sunflower morphophysiological traits

Abstract

The development of sunflower hybrids with high genetic potentials for seed and oil yields requires information on the GCA and SCA for agronomically important traits in the F1 generation. In this study were used seven new divergent cms inbred lines (A) lines, three Rf restorers utilized as testers, and 21 F1 hybrids developed at the Institute of Field and Vegetable Crops in Novi Sad. Significant differences were found between the A lines, Rf testers and their F1 hybrids for petiole length (PL), total leaf number per plant (TLN), total leaf area per plant (TLA), seed yield per plant (SY), seed oil content (OC), and oil yield per plant (OY). Analysis of variance of the combining abilities revealed highly significant differences for GCA and SCA. The nonadditive component of genetic variance (dominance and epistasis) contributed more to total genetic variance, as evidenced by the GCA/SCA ratio in the F1 generation being below the value of one for all the traits studied. The greatest average contribution to the expression of all of the traits was found in the female A lines, while the contributions of the Rf testers and line x tester interaction were less significant. Evaluation of the combining abilities of the line NS-GS-5 suggests that this line could justifiably be used as a parent in breeding programs for increasing sunflower seed and oil yields. Analysis of SCA for OY per plant identified the following hybrids as promising: NS-GS-5xRHA-R-PL- 2/1, NS-GS-6xRHA-N-49, NS-GS-2xRHA-N-49, NS-GS-1xRUS-RF-OL-168.