Effect of Copper Sulphate on Enzyme Activity and Vase Life of Lisianthus Cut Flower

In this experiment, the effect of copper sulphate at various concentrations (0, 2, 4 and mM) as peroxidase inhibitors was studied on vase life, water uptake, relative fresh weight, anthocyanin, protein and malon dialdehyde content, peroxidase (POD) and superoxide dismutase (SOD) activity and postharvest quality of Eustoma grandiflorum cv. ‘Mariachi’ The results indicated that all treatments significantly (P < 0.01) increased vase life, water uptake and relative fresh weight. Among the treatments, 6 mM copper sulphate increased vase life up to 4 days, relative fresh weight to 16% and water uptake to 4.4 g stem-1day-1 in comparison to control. Similarly copper sulphate treatment increased anthocyanin content, SOD activity, but decreased malon dialdehyde content and POD activity with no effect on protein content. Copper sulphate at 6 mM concentration showed the most SOD activity (237.33 μmol g-1 FW-1) and the lowest POD activity (0.0067 μmol g-1 FW min) in comparison to control (respectively 198 for SOD and 0.03 μmol g-1 FW-1 for POD). Also 4 mM copper sulphate produced the most anthocyanin content (94.28 mg g-1 FW) and lowest Malon dialdehyde (23.94 nmol g-1 FW-1).