Effect of preservatives on senescence of cut daffodil (Narcissus L.) flowers

We report on the effect of holding solutions containing 8-hydroxychinoline (8-HQC) and sucrose (2-10%) on senescence parameters in three daffodil cultivars. Xylem blockages obstructing water uptake in many flowers did not develop in cut daffodil scapes. The use of preservatives improved hydration of perianth but did not result in longer vase life. Only with ?Golden Harvest? was the corona longevity prolonged following application of the biocide with 6% and 10% sucrose. Changes in the structure of epidermis cells occurred after harvest: corona epidermis was more durable than that of perianth, which may account for shorter longevity of the latter element. The use of 8-HQC with 2% sucrose positively affected epidermis structure in the corona and perianth. Individual floral structures differed in their ability to accumulate sugars delivered in the preservative and translocated within the flower. Generally, supplementing flowers with exogenous sucrose results in ovary growth and not in an increased perianth longevity. However, a higher sugar content was found not only in the ovary but also in the corona of flowers held in the preservatives and this may explain a longer longevity of that floral structure as compared to perianth.