Effect of sucrose in a holding solution on some processes associated with ageing of cut carnations

Abstract

Vase-life of cut carnations and their response to a preservative (8-HQS+S) depended on the sucrose and reducing sugar content in the petals at the time of harvest. The reducing sugar level decreased in the wilted flowers kept in water and increased above the initial level in the carnations given sucrose in a holding solution. This increase in reducing sugars was small or 2-3 fold in the flowers with high and low initial sugar levels, respectively. Changes in the endogenous sucrose levels in the petals were less pronounced but a trend (i.e. increase-decrease) was also dependent on the initial sucrose level. Considerable sucrose accumulation was found in the leaves of plants placed in the solution of 5% sucrose plus 200 ppm 8-HQS. Use of an exogenous sugar in a holding solution prevented an increase in free amino acids in carnation petals, a symptom for flower ageing. Carnations placed in a preservative solution had a had anthocyanin content then the control flowers. Lower activities of acid phosphatases and RNases were found in the flowers placed in the solutions tested as compared to those kept in water.