Physiological changes associated with Sandersonia aurantiaca flower senescence in response to sugar

Sandersonia aurantiaca is a liliaceous cut flower in which senescence is not regulated by ethylene. We stood flower stems in solutions of deionized water (control) or sucrose (2%) and monitored the pattern of senescence of individual flowers attached to the stems and quantified the amount of carbohydrate and protein present in the flowers. Treatment with sucrose extended the postharvest life of flower stems by delaying the senescence of individual flowers attached to the flowering stem. Flowers on sucrose-treated stems were larger, firmer and brighter orange than the control flowers. Flowers that were treated with sucrose also contained greater quantities of carotenoids, soluble and storage carbohydrates and soluble protein than the control flowers. The first visible signs of senescence occurred prior to any net loss of soluble carbohydrate or protein. (C) 1997 Elsevier Science B.V.