Abstract:

Large-leafed Ipomoea aquatica was pretreated with 0 (as the control) and 30 mg/L 6-benzylaminopurine (6-BA),
and then stored at (10 ± 1) ℃ with 90%–95% relative humidity. Changes in the reactive oxygen species (ROS) metabolism
and quality of Ipomoea aquatica were assessed. The results showed that treatment with 30 mg/L 6-BA maintained higher
content of chlorophyll, increased the activity of superoxide dismutase, and decreased the activity of ascorbate peroxidase in
Ipomoea aquatica after 4 and 8 days of storage. However, no difference in peroxidase activity was observed between 6-BA
treatment and the control. Meanwhile, 6-BA treatment significantly delayed the decrease in endogenous antioxidants of
posthtarvest Ipomoea aquatica. For example, the decline in the contents of ascorbic acid and glutathione was slowed down.
Moreover, compared to the control sample, the increase in the production of superoxide anion radicals, and the contents of
hydrogen peroxide and malonaldehyde in 6-BA-treated samples were mitigated. These results suggested that 6-BA treatment
could alleviate the senescence of postharvest Ipomoea aquatica, thereby maintaining its quality.

Key words: Ipomoea aquatica, 6-benzylaminopurine, quality, active oxygen metabolism