Sucrose and water uptake from concentrated sucrose solutions by gladiolus shoots and the effect of these treatments on floret life

Abstract

Detached flowering gladiolus shoots (Gladiolus grandiflora cv. Oscar) were subjected to sucrose solutions with concentrations up to 50% sucrose. Sucrose was found to be absorbed at all concentrations. The amount of solution absorbed decreased when the concentration of the solution was increased, while the amount of sucrose absorbed increased up to 4.2 g sucrose per spike per 24 hours in 40% sucrose. Increasing the concentration beyond 40% resulted in the same amount of sucrose uptake while the rate of solution uptake was decreased. Continuous treatment of the shoots with sucrose resulted in continuous sucrose uptake at all concentrations, but transferring the shoots to tap water caused an increased uptake of water which was dependent on the amount of sucrose previously absorbed. Sucrose was also absorbed by leaves although at lower rates since it induced stomatal closure. The florets were found to be the most active organs for sucrose accumulation and the subsequent water uptake. Sucrose pretreated florets were found to last longer with their maximal weight achieved 2 days later than control. The maximum gain in weight in the treated shoots was 80% compared to 15% in the water control.