Disorder of Cutting of Chrysanthemum ‘Jimba’ after Hot Water Treatment and Action of Light Irradiation

Abstract

To elucidate the cause of failure of cutting of chrysanthemum following hot water treatment, we investigated the occurrence of the disorder and action of light after hot water treatment using autumn flowering ‘Jimba’. After hot water treatment, the damage became greater as the amount of light increased, and it was shown that light is involved in the occurrence of the disorder. In addition, it was suggested that the disorder was alleviated by placing the cutting of chrysanthemum for darkening for 48 hours or more after hot water treatment, and it recovered from damage due to light irradiation. Furthermore, on examining the maximal quantum efficiency (FV/FM) measurement values of chrysanthemum leaves after treatment with 48°C hot water for 1 minute, a decrease in the FV/FM value occurred, and after 72 hours at 20°C under darkening conditions, FV/FM value recovery was confirmed. Considering these facts, although leaf burn due to light inhibition occurred immediately after hot water treatment, it was suggested that photosynthesis recovered by darkening for 2 to 3 days, and it was effective as a measure to avoid the occurrence of the disorder. In addition, treatment with ascorbic acid added to hot water reduced the occurrence of the disorder. This indicates that increasing the active oxygen scavenging ability of chrysanthemum is effective as a method to avoid the occurrence of the disorder.