Influence of pre-harvest methyl jasmonate application on the fruit quality of strawberry cv. Paros at harvest and during cold storage

Purpose: Strawberry fruits are perishable with a short shelf life. Methyl jasmonate (MJ) is a well-known signaling molecule involved in the regulation of many processes in plants. Previous studies have addressed the effectiveness of pre- and postharvest MJ treatments on the quality of fruits. Therefore, in this study, the effect of pre-harvest MJ on the quality and physio-chemical traits of strawberry at harvest and during cold storage were investigated. Research Method: The effect of pre-harvest foliar spraying of MJ (0, 50, 100, and 200 μM) at three times (full flowering, production of green fruits, and the beginning of the pink stage) on quality and bioactive compounds of strawberry fruit (cv. Paros) stored at 4 °C for 12 d was studied. Findings: Our results showed that fruit obtained from MJ-treated plants had significantly higher firmness and APX enzyme activity than fruit from control plants. However, no significant differences in other traits were observed between control and MJ-treated fruits at this stage. During cold storage, MJ treatment significantly reduced firmness loss, physiological loss in weight, and ascorbic acid content compared to control fruits. In cold storage, MJ treatment reduced firmness loss and weight loss, while maintaining higher levels of titratable acidity, antioxidant compounds (ascorbic acid, anthocyanins, and phenolics), and total antioxidant activity. Furthermore, MJ treatment resulted in increased catalase and ascorbate peroxidase enzyme activity, as well as lowered guaiacol-peroxidase, total soluble solids/ titratable acidity ratio. Total soluble solids were not affected by MJ treatment at harvest and during cold storage. Research limitations: No limitations were found. Originality/Value: Pre-harvest application of MJ, especially 200 μM, can increase the shelf life of strawberry fruits by increasing or maintaining higher levels of bioactive compounds and antioxidant enzyme activity.