Evaluation of physiological characteristics of Tuberose cut flower (Polianthes tuberosa cv. Double) in response to melatonin application

Tuberose flower is one of the aromatic bulbous flowers in tropical and subtropical regions. In order to study the effects of exogenous melatonin (M) on some physiological parameters of cut flower Tuberose, an experiment was performed base on a completely randomized design(CRD) with three replicates and 15 flower per replication. Melatonin (in concentrations of 0 and 250 μL.L-1 for 4 hours) was used as pulse-treatment. Melatonin treatment compared to the control prevented the decrease of Relative water content (RWC), the increase of Electrolyte leakage (EL), and malondialdehyde (MDA) concentrations in the tissues (leaves and petals). In addition, melatonin increased the amount of ascorbate peroxidase (APX) and peroxidase (POD) activities in the 6th day of storage compared to 3rd and 0th days. Peroxidase activity decreased in control treatment on 3rd and 6th days, respectively. While the activity of this enzyme was increased in melatonin treatment. The catalase (CAT) activity content of the tissues (leaves and petals) increased on 3rd day of storage and decreased on the 6th day. Therefore, it seems melatonin may help reduce oxidative stress and the lipids peroxidation and delays process of senescence in Tuberose flower.