Abstract: Postharvest kiwifruits (Actinidia chinensis) ‘Huayou’ were grouped and dipped in 0, 0.05, 0.10, 0.20 or 0.50 mmol/L melatonin (MT) solution for 10 min at room temperature, and then stored at (0.0 ± 0.5) ℃ (90%–95% relative humidity) for 90 d. The results showed that compared with other treatment groups, 0.10 mmol/L MT apparently delayed the decline of kiwifruit firmness and color L* value, effectively reduced the respiration rate and ethylene production rate and kept lower mass loss rate and decay incidence during storage. Compared with the control, 0.10 mmol/L MT reduced the activity of amylase, delayed the decline of starch contents, maintained higher superoxide dismutase, ascorbate peroxidase and glutathione reductase activity, increased the peak of catalase, and significantly increased the contents of ascorbic acid and glutathione. These results suggested that pre-storage application with 0.10 mmol/L MT retarded the ripening and senescence of kiwifruits under low temperature storage conditions.

Key words: melatonin, ripening and senescence, low temperature storage, kiwifruit