Effect of arginine and methyl jasmonate on chilling injury and nutritional quality of ‎pomegranate fruit cv "Malase Saveh" ‎

Chilling injury is the main problem of pomegranate fruit during storage at below 5 °C, which is associated with browning husk, arils pomegranate and loss of its nutritional quality. In this experiment, the effect of intraction between arginine (0, 1 and 2 mM) and methyl jasmonate (0, 0.1 and 0.2 mM) in form of foliar spraying on the tree in three stages of 60, 40 and 20 days before harvest for redducing chilling injury and keeping nutritional quality of pomegranate were evaluated on 0, 30, 60, 90 and 120 days at 4± 0.5 °C during storage. The results showed that combined treatment between arginine (2 mM) and methyl jasmonate (0.1 mM) led to reducing chilling injury (37.74 %), electrolyte leakage (31.42 %) and malondialdehyde accumulation (29.46 %). Also, pomegranate treated with intraction treatment between arginine (2 mM) and methyl jasmonate (0.1 mM) exhibited higher ascorbic acid content, phenylalanine ammonia-lyase, phenols and anthocyanins and lower polyphenol oxidase enzymes activity which ultimately increased the antioxidant capacity of fruits. This treatment increased the enzyme activity of ascorbate peroxidase, catalase and superoxide dismutase by 9.04, 8.18 and 44.21%, respectively, in comparison with the control, leading to reduction the accumulation of hydrogen peroxide in these fruits. Thus, combined treatment between arginine and methyl jasmonate via enhancing antioxidant system, and reducing chilling injury led to enhanced nutritional quality, maintained safe membrane integrity and marketable.