Abstract: The effect of methyl jasmonate (MeJA) combined with low temperature conditioning (LTC) on physiological and biochemical parameters in hot pepper during postharvest storage was investigated. In this experiment, “Jinyinda” peppers were soaked in 5 μmol/L MeJA solution for 10 min, and then taken out and dried before being stored at 10 ℃ for 2 days and then transferred to storage at 4 ℃, and they served as a combined treatment group. In the LTC treatment group, water instead of MeJA solution was used. The chilling injury index, chlorophyll and vitamin C and malondialdehyde (MDA) content, the activities and gene expression of antioxidant enzymes were measured during storage. The results showed that MeJA + LTC treatment could effectively inhibit chilling injury, delay the decrease in chlorophyll and VC content, suppress the increase in MDA content and maintain cell integrity. MeJA + LTC treatment maintained the activities and gene expression of peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) in pepper fruit. These results indicated that MeJA combined with LTC could reduce the chilling injury, maintain the storage quality and prolonged the shelf life of hot peppers. Therefore, MeJA combined with LTC should be recommended for improving the storage quality and antioxidant capacity of hot peppers.

Key words: hot pepper, low temperature conditioning, methyl jasmonate, chilling injury, postharvest physiology