Evaluation of Ornamental and Postharvest Potential of Oil-Type Sunflower Genotypes Grown Under Dense Sowing Conditions

Sunflower is predominantly cultivated and extensively studied as an oil-type crop, which has contributed to the development of broad genetic variability within oil-type germplasm. In contrast, ornamental sunflower has received considerably less research attention. Therefore, the existing genetic variability of oil-type sunflower represents a valuable resource that can be explored and tested for ornamental traits, including postharvest performance and suitability for cut-flower production. This is particularly relevant given the increasing market demand for decorative sunflower types and the growing interest in diversified cut-flower assortments. The objective of this study was to assess the ornamental potential of oil-type sunflower genotypes, with particular emphasis on postharvest performance of cut-flowers. Genotypes from the breeding collection of the Institute of Field and Vegetable Crops, Novi Sad, were evaluated for key ornamental morphological traits and postharvest longevity. The experiment comprised treatments combining two storage regimes (room conditions and chamber storage) and two holding solutions (distilled water and 10% sucrose), applied across two sowing dates. To identify possible structural determinants of postharvest behavior, three morphologically contrasting genotypes (ĆMD U 12, AS 87, and LIP P 98) were further subjected to anatomical analysis of the peduncle. Postharvest longevity was significantly affected by genotype, sowing date, storage regime, sucrose treatment, and their interactions, demonstrating the strong influence of both genetic background and postharvest handling conditions. Chamber storage consistently affected postharvest longevity in most genotypes, while sucrose supplementation further improved it in several genotypes. Substantial genotypic variation in postharvest performance was detected. Substantial genotypic variation in postharvest performance was detected. Genotype ĆMD U 12 exhibited outstanding postharvest longevity under several storage environments, particularly in the second sowing date, whereas AS 87 showed markedly reduced postharvest longevity, particularly under ambient storage conditions. Morphological traits alone were not reliable predictors of postharvest longevity. In contrast, anatomical analyses revealed clear differences in peduncle tissue organization and vascular architecture among the selected genotypes, indicating that variation in supportive tissues and xylem vessel characteristics may play an important role in postharvest water relations and flower postharvest longevity. The results demonstrate the potential of IFVCNS oil-type sunflower germplasm for developing ornamental cut-flower genotypes adapted to dense sowing conditions, while also identifying postharvest treatments that significantly improve postharvest longevity and commercial usability.