Plant growth regulator effects on sunflower parents and F1 hybrids

Abstract

The need for augmented sunflower production requires finding new meth­ods and improving existing cultivation technologies to increase performance and resistance to stresses. The low performance of breeding and seed production lines is among obstacles to the rapid introduction of new and modern sunflower hybrids into production. The study purpose was to evaluate the individual responses of self-pollinating sunflower lines intended for breeding and seed production and of F₁ hybrids, which were developed by crossing these lines, to plant growth regulators. It was found that the CMS-based lines had better yield elements and oil content in response to growth regulators compared to the lines based on normal cytoplasm. The plant growth regulators increased the heterosis effect in the experimental hybrids. The best response was observed in the threeline hybrid Skh808A/Kh1002B × Kh785V for all the studied parameters. The growth regulators strengthened a correlation between the 1000-seed weight and yield (r = 0.51–0.97). The oil content in seeds of F₁ hybrids depended on the genotype and could be comparable both with the parent with a low content of oil and with the high-oil parent. Variations in the oil content in seeds depended on the type of growth regulator and soil/climatic conditions during the seed filling.