Chilling Injury and Electrolyte Leakage in Fruit of Different Tomato Cultivars1

Abstract Mature-green tomato fruit from 2 chilling-sensitive cultivars and 2 chilling-tolerant breeding lines, all derived from Lycopersicon esculentum Mill., were harvested and chilled at 5°C for 0, 2, 7, and 15 days. Mature-green fruit analyzed immediately after chilling showed higher electrolyte leakage in chilling-sensitive than chilling-tolerant lines. However, electrolyte leakage from chilled fruit that were ripened before analysis was higher in normal-sized than in cherry cultivars and seemed to be a function of fruit type rather than of chilling sensitivity. Unchilled field samples of these cultivars harvested at the mature-green, turning, and full-ripe stages and analyzed immediately showed an electrolyte leakage pattern similar to that found for comparable chilled mature-green fruit. No significant differences were found in calcium content (total, bound, or soluble) or in pectinase activity between chilling-sensitive or -tolerant cultivars.