Endogenous levels of polyamines during cold storage of bird-ofparadise treated with biocides

This study aimed to analyse the endogenous levels of free polyamines putrescine (Put), spermidine (spd) and spermine (spm) under the effect of 8-HQC (8-hydroxyquinoline citrate) and chlorine during cold storage of bird-of-paradise floral scapes. Flowers were selected, labelled and randomly distributed in recipients for postharvest trials. The base of flower scapes was immersed with pulsing treatments (Control, 100 chlorine, 250 or 500 mg L-1 8-HQC) for 48 h, thereafter, stored at 10.5 °C and 90% relative humidity for a period of 12 days. Flower parts were sampled for polyamines analysis at day 0, 4, 8 and 12 days during storage. All samples had higher Put levels than the control. Treatment with 500 mg L-1 8-HQC showed the highest Spd levels in bracts, while chlorine treatment had the highest Spm levels in stems.