Effect of sucrose in a vase solution on postharvest performance in non-STS treated cut carnation flowers

Cut carnation flowers (standard type 'Excerea') without STS treatment were kept in 0 or 5% sucrose with anti-bacterial agent at 23°C under a light intensity of 20 µmol m^-2 s^-1, provided by fluorescent lamps with a 16-h photoperiod. The cut flowers kept in 5% sucrose showed a higher increase of fresh weight than those kept in 0% sucrose. The cut flowers kept in 0% sucrose showed petal softening and wilting much earlier than those kept in 5% sucrose. The cut flowers kept in 0% sucrose started ethylene production on day 7 while those kept in 5% started ethylene production on day 13. A higher accumulation of sugar in petals was observed in the cut flowers kept in 5% sucrose. The expression of Dc-EIL3, DcACO1 and DcACS1 was up-regulated in the petals of the cut flowers kept in 0% sucrose, although the period of the up-regulation was different among the genes. Continuous treatment of cut flowers with 5% sucrose suppressed the up-regulation of Dc-EIL3 and delayed the periods of the up-regulation of DcACO1 and DcACS1 in the petals. The present study demonstrates that sucrose in a vase solution delays the ethylene production of cut carnation flowers, resulting in a delay of flower senescence.