Chilling Sensitivity of Tomato Fruit in Relation to Ripening and Senescence

Abstract

Abstract Postchilling ion leakage, respiration, and C2H4 biosynthesis were used to measure the degree of chilling injury to fruit of tomato (Lycopersicon esculentum Mill. ‘Heinz 1350’). Chilling sensitivity, as measured by ion leakage, first declined as the tomatoes began to ripen and then increased during the late stages of ripening. Both C2H4 biosynthesis and respiration rate were stimulated during the chilling response early in ripening. In the nonripening mutant, nor, chilling sensitivity did not show the early decline but showed the increase during senescence. Variation in chilling sensitivity during tomato ripening was biphasic, with a decline at the onset of ripening followed by a senescence-related increase. It is proposed that the latter may be due to an increase in membrane viscosity.