Continuous Requirement of Ethylene for Apple Fruit Volatile Synthesis

Pre- and postclimacteric Super Red Delicious apple ( Malus domestica Borkh.) fruit were treated with ethephon, aminoethoxyvinylglycine (AVG), and diazocyclopentadiene (DACP) after harvest. Ethylene and volatile production were measured 1, 5, and 13 days after treatment. Production of some esters by preclimacteric fruit was enhanced after ethephon treatment, but the same treatment reduced production of various esters by postclimacteric fruit. Ethylene and volatile production were inhibited by AVG and DACP in preclimacteric fruit. Volatile acetate esters were not affected by any treatment, whereas AVG and DACP inhibited production of other volatile esters in postclimacteric fruits. The results suggest synthesis of some volatile esters requires continuous ethylene action and a high rate of ethylene production.