The longevity of cut flowers of Iranian narcissus is affected by genotype, physiochemical characteristics and stem structural factors

Flower longevity is one of the critical factors in determining the quality of cut flowers. narcissus, a popular cut flower in Iran, is cultivated outdoors in the fall and winter. Despite numerous studies on extending the longevity of narcissus flowers, our understanding of internal changes in floral tissues during the postharvest period is limited. This study aimed to investigate the morphophysiological and biochemical changes in floral tissues during postharvest conditions in Iranian narcissus populations. Ten narcissus populations were collected from various regions of Iran and cultivated in a greenhouse. The harvested narcissus flowers were kept in vases containing distilled water. Flower longevity; physicochemical characteristics, such as relative solution uptake, electrical conductivity, relative water content, total protein, antioxidant enzyme activity, carotenoids, H2O2 and malondialdehyde; stem mucilage sugars; structural features of the stem and vascular bundles; and the number of bacteria in the vase solution were evaluated on the first and third days after harvest. The experiment was conducted in a completely randomized design with nine replications, and mean comparisons were performed via SPSS software. The longevity of flowers is influenced by genetic characteristics and floral tissues. The populations of Shahla from the Khusf region and Porpar from the Khafr region presented the greatest longevity, whereas white narcissus presented the shortest longevity. Compared with petal tissue, corona tissue has greater longevity because of its thicker structure, higher water retention capacity, lower production of free radicals, and stronger antioxidant defense system. The number of vascular bundles was significantly positively correlated with relative solution uptake. No vascular blockage was observed during the postharvest period, but stem cells collapsed on the third day of vase life, which seemed to affect water uptake. The reason for the lack of vascular blockage in the narcissus stem requires further research.