Nitric oxide (NO), a PGR, is involved in numerous physiological and molecular responses in higher plants. The study was undertaken to determine how preharvest application of NO affected physical and biochemical postharvest properties and chilling injury of tomato fruit, cv. Newton, during cold storage. Tomato plants were treated twice with 200 or 500 µM sodium nitroprusside (SNP), or distilled water, at 41 and 49 days post anthesis. For postharvest analyses samples were taken at 0, 5, 10, 15, and 20 days of storage at 1 ± 0.2°C and 90% ± 5% RH and transferred to ambient temperature (~24°C) for 2 days. The SNP delayed weight loss, increased total soluble solids, and maintained firmness of fruit during storage. Vitamin C, titratable acidity, lycopene content, superoxide dismutase, and peroxidase enzyme activity were higher due to SNP treatment than for the control. The SNP treatment decreased percent chilling injury. The 200 μm SNP concentration was best for preserving postharvest quality of tomato fruit. Preharvest application of SNP improved postharvest quality and mitigated deleterious effects of chilling injury of tomato fruit during cold storage.
