Development of the Composite Sunflower Line NSSF(S)C3 to Enhance Yield and Nutritional Value

Abstract

Sunflower is an important oilseed and food crop with significant economic value. However, most sunflower seeds cultivated in Thailand are imported hybrid varieties with high production costs. This study aimed to develop a high-yielding open-pollinated sunflower population with desirable nutritional quality. The research was conducted from 2018 to 2022. Initially, the morphological characteristics of 91 sunflower accessions obtained from the USDA Germplasm Resources Information Network were evaluated. Fifty-one well-adapted accessions were selected under Thai environmental conditions and used to establish a base population. Mass selection combined with recurrent random mating was subsequently performed over several cycles. Selection criteria included non-branching plants, vigorous growth, strong neck strength, resistance to diseases and insect pests, large head diameter, and large seed size. After three cycles of selection, the open-pollinated sunflower population NSSF(S)C3 was developed, with an average oil content of 26.64%. Yield evaluation was conducted during the dry season of 2022 using 15 sunflower varieties and lines arranged in a Randomized Complete Block Design with three replications. The results showed that the average seed yield was 229 kg/rai. The lines MSC318, NSSF(S)C3, 3100540, 813140 and Ames 3003 produced the highest yields, ranging from 256 to 418 kg/rai. These lines also exhibited greater head diameter, seed set percentage, and 1,000-seed weight than the experimental mean. Nutritional analysis indicated that NSSF(S)C3 combined high seed yield with a high seed oil content. The results demonstrated that the NSSF(S)C3 open-pollinated population possesses superior yield potential favorable yield components and desirable nutritional quality. Therefore, it can serve as a valuable genetic resource for the development of high-yielding sunflower cultivars. Further evaluation across multiple locations and growing seasons is recommended to assess yield stability and environmental adaptability.