Senescence of the Cut Carnation Flower: Respiration and Sugar Status

SummaryThe quantitative changes in the ethanol-soluble sugars (glucose, fructose and sucrose) of carnation petals, estimated as glucose equivalents, are described for flowers standing in a germicide, with or without 4 % sucrose, at 18.3 °C. At harvest the reducing sugar content of the petals is about 2 to 3 % of the fresh weight, and sucrose about 0.3 to 1.0%; about half of the initial reducing sugar and a trace of sucrose remain when the petals wilt. Flower petals accumulate glucose, fructose and sucrose when their stems are placed in a sucrose/germicide solution.Comparison of the longevities of the flowers fed with 4 % sucrose in combination with one of three unrelated germicides (silver nitrate; hydroxyquinoline sulphate; dichlorophen) supports the view that sucrose is the more important component for delaying senescence. Flowers treated with [14 C]sucrose evolve 14 CO2 indicating that the sucrose is metabolized. The respiration of whole flowers and petal discs was measured and the results are discussed in relation to senescence of the flower.