Manipulation of ripening progress of different plum cultivars during shelf life by post-storage treatments with ethylene and 1-methylcyclopropene

In order to manipulate ripening progress and increase marketing acceptance, plum (Prunus salicina Lindl.) cultivars 'Gaixian', 'Yuhuang' and 'Aozhou 14' were treated with 500 μL L−1 ethylene or 2.0 μL L−1 1-methylcyclopropene (1-MCP) for 24 h at 25 °C after removal from the cold storage at 0 °C for 8, 4 and 4 weeks, respectively. Different patterns of physiological progresses including color changes, softening and ethylene production were observed in these plum cultivars during cold storage. Upon removal, regardless of physiological patterns, a sharp increase of ethylene production was found in either plum cultivar during shelf life and the increase was stimulated by post-storage ethylene treatment but dramatically inhibited by post-storage 1-MCP treatment. Skin color changes of 'Gaixian' and 'Yuhuang' plums during shelf life were greatly enhanced by ethylene but significantly retarded by 1-MCP. Flesh reddening occurred easily in 'Aozhou 14' during cold storage and became more serious after removal, which was hastened by ethylene but significantly alleviated by 1-MCP. Firmness decline of plums during shelf life was not significantly influenced by ethylene but effectively delayed by 1-MCP. Post-storage ethylene treatment could 'recover' the inherent epidemic color of 'Gaixian' and 'Yuhuang' during shelf life, while post-storage 1-MCP treatment could maintain fruit firmness and alleviate flesh reddening of 'Aozhou 14'. Thus the manipulation of ripening progress of plums with post-storage ethylene or 1-MCP treatment would be practical for increasing fruit marketing acceptance, though it depends on cultivars.