The Efficacies of 1-Methylcyclopropene and Chitosan Nanoparticles in Preserving the Postharvest Quality of Damask Rose and Their Underlying Biochemical and Physiological Mechanisms.

Preserving the flower shelf life of damask rose is a crucial matter in promoting its economic viability. Chitosan nanoparticles (CSNPs) and 1-methylcyclopropene (1-MCP) may potentially decrease the postharvest loss of several horticultural commodities, but no findings on damask rose have been published. Therefore, the aim of this research was to study the effect of 1-MCP (400 mg m -3 ) and either the pre- or postharvest application of CSNPs (1%) on maintaining the quality of damask rose flowers during storage at 4 or 20 °C. The shelf life of damask rose has been significantly extended, along with a reduction in weight loss due to 1-MCP, CSNPs and pre-CSNP treatments. 1-MCP or CSNP applications have resulted in a higher relative water content, volatile oil, total anthocyanins, total carotenoids, total phenolics and antioxidant activity. Ethylene evolution, H 2 O 2 generation and malondialdehyde content were significantly decreased due to 1-MCP or CSNPs treatment, and hence, the cell membrane functions have been maintained. The 1-MCP or CSNP-treated flowers have shown higher activities of catalase and ascorbate peroxidase and lower activities of polyphenol oxidase and lipoxygenase in comparison to untreated flowers. Our results showed that the postharvest application of 1-MCP or CSNPs is a very promising method to maintain the postharvest quality of damask rose during storage.