Difference of ethylene production and response to ethylene in cut flowers of dahlia (Dahlia variabilis) cultivars

Cut dahlia flowers have a short vase life of 3–7 days, and some cultivars exhibit petal abscission, even inside of cardboard boxes during transport. This petal abscission is induced by ethylene in many cases. In the present study, we investigated the role of ethylene in dahlia flower senescence by comparing the responses to ethylene, ethylene inhibitors, and ethylene production among cultivars. Exogenous ethylene significantly accelerated petal abscission in seven cultivars and petal wilting in other five cultivars out of 12 cultivars. Whole florets and detached receptacles (with bracts) produced different amounts of ethylene; ethylene production was higher in ‘Carnelian’ and ‘Port Light Pair Beauty’ than ‘Heavenly Peace’ and ‘Purple Stone’. Onset of senescence was delayed in detached petals compared with attached petals, suggesting that petal abscission was induced by ethylene produced by ovary and receptacles. The ethylene action inhibitor 1-methylcyclopropene inhibited petal abscission and delayed petal wilting in eight cultivars. Moreover, the silver thiosulfate complex delayed petal wilting of ‘Carnelian’. Together, our findings suggested that ethylene plays a role in senescence of cut dahlia flowers and ethylene inhibitors can extend their vase life.