Melatonin as a new postharvest treatment for increasing cut carnation (Dianthus caryophyllus L.) vase life

The marketability of cut flowers is directly affected by their vase life, which determines acceptability for commercial purposes. In carnations and other species of cut flowers, corolla is one of the most affected parts during flower senescence due to the petal withering which is accelerated by metabolic processes occurring after separation from the mother plant. Melatonin (MT) is a compound with antioxidant properties, naturally present in plant tissues that plays important roles in the regulation of different metabolic processes. In this research work the effect of different MT concentrations (0.01, 0.1 and 1 mM) on the vase life of cut carnations flowers cv. Baltico was evaluated. The greatest delay in senescence was observed with 0.1 mM MT concentration, increasing vase life up to 10 days more as compared to control carnations. Although all MT concentrations assayed significantly (P < 0.05) maintained initial levels of fresh weight, membrane stability index, bioactive compounds and antioxidant activity for longer time, the lowest concentrations were those that had the most relevant impact on vase life. The highest dose evaluated (1 mM) maintained all the parameters evaluated but showed the wilting symptoms earlier. For this reason, 0.1 MT concentration could be a tool capable of improving carnation vase life for longer time, increasing the commercial potential of this cut flower.