Effects of Ethylene and Propylene on Post-Harvest Development and Ripening of Young Normal and Mutant Tomato Fruits

Abstract

When tomato fruits of cv. Rtugers (normal), and of the rin and nor mutants were detached 10 days after anthesis (24% of the total growth period), they usually developed a characteristic swelling of one or more locules, which eventually developed a red, yellow or yellow-orange colour typical of the mature fruits of each strain. The remainder of the fruit tissues lost chlorophyll and eventually became necrotic. Ethylene treatment (25 �l/l) started 2 h after harvest advanced the onset of swelling in 10-day fruits of all strains. Treatment that was started 7 days after harvest had no effect on the onset of swelling in Rutgers and rin and had only a small effect on nor fruits. When ethylene was applied before first visible swelling (FS), the undeveloped portions of the fruits rapidly became necrotic and this necrosis spread to the swollen locules before they coloured. From FS and onwards, ethylene increased the rate of swelling and advanced colouring of the swollen locules. In some treated rin fruits, the swollen locules became intensely pink or red. Propylene treatment (500 �l/l) started 2 h after harvest also advanced the onset of swelling and red colour development in swollen locules in Rutgers fruits, as well as advancing the onset of the respiratory climacteric and the associated rise in ethylene production. Swelling in both control and propylene-treated fruits was not associated with any marked changes in respiration and ethylene production.