Effects of exogenous sucrose on carbohydrate levels, flower respiration and longevity of potted miniature rose (Rosa hybrida) flowers during postproduction

Abstract The effect of continuous injection of exogenous sucrose on single flower postproduction longevity of attached flowers of potted ‘Meijikatar’ miniature roses was studied. At bud showing color, with sepals starting to unfold, plants were moved to interior conditions and started being continuously injected with a solution of 3% sucrose or distilled water. Carbohydrate levels, flower respiration and single flower longevity were assessed. There was some variability in the amounts of solution supplied to the plants. Infusion of exogenous sucrose increased attached miniature rose flower longevity by 1.5 days and also increased flower respiration rates. The higher the uptake rate of sucrose solution the longer the flowers lasted. Exogenously supplied sucrose was consumed by increased respiration and consequently, at day 6 after anthesis, no differences were found in nonstructural carbohydrate levels between water and sucrose treatments. However, percent of soluble sugars in the stem was higher in the sucrose-infused plants, suggesting that exogenous sucrose supply not only served as an extra source of respirable carbohydrates but also released stored carbohydrates to flower respiration. At flower death, leaf soluble sugars and total non-structural carbohydrates were higher in the sucrose infusion treatment and, independently of infusion treatment, flower soluble sugars and total non-structural carbohydrates positively correlated with flower longevity.