Ripening and Storage Characteristics of the ‘Alcobaca’ Ripening Mutant in Tomato

Abstract

Storability, ripening, and fruit characteristics were studied in fruit of tomato ( Lycopersicon esculentum Mill.) from plants heterozygous or homozygous for alc . Ripe fruit from heterozygotes showed a 78% increase in storability compared to ‘Rutgers’. Full ripe fruit of the homozygous recessive showed over 300% increase in storability, with a mean storage life of 40 days. Increased storability is not associated with initial fruit Firmness, but is accompanied by a decrease in the rate of fruit softening during storage of the fully ripe fruit. This trait does not affect pH, soluble solids, or the time required for development from flowering to mature-green fruit. The rate of further ripening is decreased. The degree of ripeness obtained by the mutant fruit is dependent on its ripeness when the fruit is picked. Mutant fruit will not fully ripen off the vine unless picked when the fruit is already at the late streak to light color stage. Ethylene production is reduced in detached, mature-green ‘Alcobaca’ fruit to 25% of that observed in ‘Rutgers’. A climacteric pattern of ethylene and CO 2 production was not observed in single, detached fruit of ‘Alcobaca’ or other alc lines. The highest ethylene production detected externally was observed in the first (day one) reading of alc fruit, regardless of maturity of fruit when picked. Afterwards, ethylene production decreased to 2.5 to 3 μl·kg −1 hr −1 . The stage of ripeness at harvest affects the level of ethylene production of detached fruit. The maximum day-one ethylene readings were obtained from fruit harvested at the turning (40% color) stage. The rise in ethylene production during ripening also was detected in internal gas samples.