Effect of 2,4-epibrassinolide treatment on the postharvest quality and physiological metabolism of fresh daylily flower buds during storage

- 2,4-epibrassinolide (EBR) improves cell membrane integrity of daylily.
- EBR upregulates the activity of antioxidant enzymes of daylily.
- EBR maintains high gibberellic acid content, zeatin riboside content and reduced abscisic acid content.
- EBR preserves the postharvest quality of daylily at 4 °C.

Flower buds of daylily are perishable, which limits their taste and consumer acceptability. This study aims to research the effects of 2,4-epibrassinolide (EBR) on the postharvest quality and physiological metabolism during senescence of fresh daylily flower buds during storage. The buds were sprayed with an aqueous solution containing 0.5 mg L−1 EBR, dried for 1 h and then stored at 4 ± 1 °C for 24 days. The results were as follows: EBR treatment decreased electrolyte leakage and malondialdehyde (MDA) content, suggesting maintaining the membrane integrity of daylily flower buds. EBR treatment inhibited the accumulation of H2O2 content, and increased the activity of antioxidant enzymes including superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, suggesting active oxygen metabolism in the buds. EBR treatment enhanced gibberellic acid and zeatin riboside content, and reduced abscisic acid content, suggesting sustained balance of plant hormones. These results indicated that EBR treatment preserved postharvest quality including sensory quality, chlorophyll content and weight loss of daylily flower buds during storage. This study suggested that EBR treatment offers the potential to delay the senescence of stored daylily flower buds and extend their postharvest life.