EXTENDING VASE LIFE OF CUT Strelitzia reginae Aiton FLOWERS BY COBALT CHLORIDE, CERIUM NITRATE, SILVER NANOPARTICLES AND NANOSIL

Cut flowers of Strelitzia reginae Aiton (Strelitziaceae) generally have a short vase life. Vascular blockage is a major reason for this. In this paper, we evaluated the effects of pulse treatment with disinfectants including cobalt chloride (CoCl2), cerium nitrate (Ce(NO3)3), silver nanoparticles (SNP) and Nanosil on the vase life and physiological characteristics of cut S. reginae flowers stems. Cut flowers kept in the vase solution containing these disinfectants showed significant increase in solution uptake, the content of total protein and pigments of petals, the activities of antioxidantive active enzymes superoxide dismutase (SOD) and ascorbate peroxidase (APX). Also, the number of stem-end bacteria and malondialdehyde (MDA) content in cut flowers were decreased as compared to control. Based on obtained results, we introduce Ce(NO3)3 as the most effective treatment to extend the vase life of cut S. reginae flowers. More so with the concentration of 300 µM which induced the maximum solution uptake and SOD and APX activities that resulted in the longest vase life. Findings of the present study suggested that Ce(NO3)3 prolonged postharvest longevity of S. reginae by increasing the solution uptake and SOD and APX activity and decreasing the MDA content. The use of Ce(NO3)3 reduces the use of chemicals and make saving in costs. The highest bacterial population of micro-organisms on cut stem ends were Escherichia coli, Bacillus, Staphylococcus and Streptococcus. Cerium nitrate had the strongest effect on reduction of these bacterial population and yeast.