Effects of low temperature phosphine fumigation on postharvest quality of white chrysanthemum ‘Dabaiju’

Abstract

White chrysanthemum (Dendranthema morifolium Tzvel.) is sensitive to methyl bromide (MB) fumigation. ‘Dabaiju’, a widely known cultivar of white chrysanthemum in China, was fumigated with three phosphine dosages of 0.76, 1.52, 3.04mgL−1 and four exposure durations of 2, 5, 8, and 11 days at 2°C. Effects on flower appearance parameters including fresh weight loss (FWL), vase life, and flower diameter, and physiological indices including respiration, soluble protein, malondialdehyde (MDA), proline, and electrolyte leakage (EL) were investigated. The result showed that interaction between duration and dosage was the most critical factor affecting the appearance parameters and physiological indices during fumigation. Less than 5 days fumigation with all phosphine dosages tested did not result in any significant changes on flower appearance and physiological indices. However, fumigation with 1.52 and 3.04mgL−1 phosphine significantly decreased vase life and flower diameter for 11 days exposure, and increased respiration, decreased soluble protein, accelerated accumulation of MDA and proline, and enhanced EL for more than 5 days fumigation. In combination with information on phosphine toxicity to insect pests at lower temperatures in present literatures, it is strongly suggested that phosphine fumigation of white chrysanthemum ‘Dabaiju’ at low temperature be a viable replacement of MB fumigation.