Abstract:

To determine the chilling tolerance of cucumber fruit after harvest, cucumber (Cucumis sativus L. ‘Jinyou 1’) fruit were stored at 2 °C for 9 days before ripening at 20 ℃ for 2 days. Chilling injury index, electrolyte leakage, activities of phospholipase D (PLD) and lipoxygenase (LOX), membrane-associated Ca²⁺ content in the calyx, middle and stalk sections of cucumber fruit were determined, respectively. Chilling injury occurred initially in the calyx area, and developed toward the middle and stalk end. After storage, chilling injury index, electrolyte leakage, activities of PLD and LOX in calyx section were highest, and lowest in stalk section of the fruit. Content of membrane-associated Ca²⁺ increased from calyx to stalk. Date indicated that increasing tolerance to chilling temperature from calyx to stalk of cucumber fruit was significantly related with the stimulation of PLD and LOX activities and decrease of membrane-associated Ca²⁺ content.

Key words: cucumber, chilling injury, PLD, LOX, calcium