Effect of Methyl Jasmonate Foliar Application on Some Qualitative Attributes and Phytochemical Contents of ‘Rabab’ Pomegranate Fruit

In order to evaluate the effects of methyl jasmonate on quality of ‘Rabab’ pomegranate, an experiment was conducted as a completely randomized design with 3 replications. Trees were sprayed with different concentrations of methyl jasmonate (0, 0.1, 0.3, and 0.5 mM) at four different stages of fruit development including full bloom, 30, 60, and 90 days after full bloom.Control trees were sprayed with distilled water. Some quality attributes of the fruit including fruit fresh weight, soluble solids content, pH, total acidity, total phenolics, total antioxidant activity, color index, and ascorbic acid content were evaluated. Methyl jasmonate at a concentration-dependent manner enhanced fruit quality attributes including phytochemical compounds. MeJA at 0.5 mmol L−1 significantly (P≤0.05) enhanced fruit fresh weight, pH, total phenolics, antioxidant activity, and ascorbic acid content and reduced total acidity of fruit juice. Fruits sprayed with 0.5 mmol L−1 caused a significant increase of ‘a’ and chroma indexes. The higher values of L, b value and Hue angel were observed in fruits pretreated with 0.1 mmol L-1 MeJA and control fruit. According to the findings of this study, foliar spraying with 0.5 mmol L−1 MeJA may be considered as an effective nonchemical method for enhancing pomegranate fruit quality attributes and phytochemical compounds.