Variation Of Cold Tolerance Among Different Kiwifruits And Effects Of Advanced Harvest And1-MCP Treatment On Chilling Injury

Kiwifruit is sensitive to low temperature, the chilling injury symptoms and the time itoccered are different among different types and varieties.Kiwifruit of three cultivars werestored at （0±0.5）℃to study the differences of chilling injury among them，and study theeffects of advanced harvested fruits on chilling injury,and study the effects of1-MCP(0.5μL·L^-1) treatment on postharvest chilling injury of normal maturity fruits, which Providereference for identification and control of chilling injury. The main results were as follows:1. Chilling tolerance of kiwifruits showed differences among three cultivars.‘Hongyang’and‘Huayou’（Actinidia chinensis） exhibited more chilling-sensitive and occurred chillinginjury earlier than‘Xuxiang’（Actinidia deliciosa）.The chilling injury index,chilling injuryincidence, malonaldehyde content and lipoxygenase activity of‘Hongyang’and‘Huayou’weresignificantly higher than that of ‘Xuxiang’at later storage,while ethylene production andrespiratory rate maintained in high levels at earlier stage.‘Xuxiang’exhibited lighter chillinginjury, maintained higher peroxidase activity and lower polyphenol oxidaseactivity than thatof‘Hongyang’and‘Huayou’during storage.It also had higher accepted fruit ratio and lowerweight loss than that of‘Hongyang’and‘Huayou’, and the firmness of‘Huayou’decreasedquickly. Results showed that‘Hongyang’and‘Huayou’were more sensitive to low temperaturethan‘Xuxiang’.2. The advanced harvest fruits suffered serious chilling inury, had higher weight lossratio and lower accepted fruit ratio compared with normal maturation after90days storage.The former two had high firmness and titratable acid, and low soluble solids content after90days storage. The membrane permeability and malondialdehyde content of the former twoharvests growing faster than normal harvest. Results indicated that advanced harvestedkiwiruits were more sensitive to low temperature, and suffered serious chilling injury.3. Results indicated that application of1-MCP (0.5μL·L^-1) efficiently reduced thechilling injury of ‘Xuxiang’ kiwifruit, but it enhanced the chilling injury of ‘Hongyang’, andhad no effects on‘Huayou’.