Fig. 5

Effects of 1-MCP and ethephon on fruit firmness, respiration rate and ethylene production during papaya fruit postharvest ripening. A Appearance of papaya fruits during natural, 1-MCP-delayed and ethephon-induced ripening. B Changes in firmness. C Respiration rate. D Ethylene production rate. The green-mature papaya fruits were harvested, and then separately treated with 0.5 g/L ethephon for 5 min, and 0.5 μL/L 1-MCP for 2 h. The untreated fruits were used as a control. Each experiment was conducted with three biological replicates, and each replicate with three fruits. The red asterisks indicate significant differences between CK and 1-MCP treatments, and black asterisks indicate significant differences between CK and ethephon treatments by Student’s t-test: * P < 0.05; ** P < 0.01; *** P < 0.001, respectively