Effect of 8-Hydroxyquinoline Citrate, Sucrose and Peroxidase Inhibitors on Vase Life of Lisianthus (EUSTOMA GRANDIFLORUM L.) Cut Flowers

Cut lisianthus flowers have a short vase life, possibly due to blockage of xylem vessels. The effect of 8-hydroxyquinoline citrate, sucrose and peroxidase inhibitors on delaying senescence and extending vase life of cut lisianthus flowers was tested. The peroxidase inhibitors used in this experiment were catechol (CH) (5, 10, 15 mM) and p-phenylenediamine (PD) (5, 10, 15 mM). All vase solutions contained 200 mg-dm^-3 8-hydroxyquinoline citrate (8-HQC) and 3% sucrose. 10 mM CH treatment was the most effective for vase life extension (13.3 days), increasing water uptake, and delaying fresh weight loss. The vase solution containing 10 mM CH significantly increased superoxide dismutase (SOD) and decreased peroxidase (POD) activities. Similarly, 10 mM PD increased anthocyanin content more than the other treat–ments. Protein degradation was significantly delayed by application of 5 mM PD. The malondialdehyde (MDA) accumulation was reduced when CH at 5 mM and PD in 5 and 15 mM were added to the vase solution. Results indicated that peroxidase inhibitors in combination with 8-HQC and sucrose increase vase life of lisianthus by improving water uptake and delaying fresh weight loss.