Effects of 1-methylcyclopropene and ethephon treatment on physiological changes and reactive oxygen metabolism of postharvest‘Golden Delicious' apple fruit during storage at ambient temperature

Effects of 1 μL/L 1-methylcyclopropene ( 1-MCP) and 0.2 mmol/L ethephon on physiological changes and reactive oxygen metabolism of postharvest ‘Golden Delicious ' apples during storage at ambient temperature were investigated. The results showed that, compared with controls, 1-MCP treatment effectively delayed fruit softening, the decline of titratable acid ( TA) content and the increase in total soluble solids ( TSS) ; obviously inhibited chlorophyll degradation, respiration rate and ethylene production; increased the activity of superoxide dismutase ( SOD) , catalase ( CAT) and peroxidase ( POD) ; retarded superoxide anion ( O-2·) generation rate, the accumulation of H2O2 and malondialdehyde ( MDA) . Ethephon treatment mainly promoted fruit softening and the decline of TA content at the early storage period, accelerated the chlorophyll degradation and ethylene production, and also made the respiratory rate peak ahead of control. It had opposite effects on reactive oxygen metabolism mentioned above while had no significant effect on TSS content. In conclusion, 1-MCP treatment maintained the storage quality of postharvest apple fruit at ambient temperature, whereas ethephon treatment had opposite effects on it, the metabolism of reactive oxygen during postharvest storage of apple fruit was related to ethylene.