Abscission of mango fruitlets as influenced by enhanced ethylene biosynthesis.
Núñez-Elisea R., Davenport T. L.
Author Affiliation: University of Florida, Homestead, FL 33031, USA.
Plant Physiology 82 : 991-994
Abstract : Experiments were conducted on developing fruitlet explants (consisting of the immature fruit, the pedicel, the abscission zone and peduncle) to establish the source and dynamics of ethylene production prior to and during fruitlet abscission. Abscission at 100% occurred 86 and 74 h after harvest for cultivars Keitt and Tommy Atkins, respectively. An increase in the rate of abscission began 62 h after harvest and was preceded by enhanced ethylene synthesis which occurred approximately 48 h prior to abscission and peaked near the time of abscission. Seeds produced the highest amount of ethylene per gram FW, but the pericarp was the main source of ethylene on an absolute basis, since it represented more than 85% of total fruitlet weight. Pedicels containing the abscission zone produced no detectable ethylene prior to or at the moment of abscission. Fumigation of Tommy Atkins fruitlets with 1, 15, or 100 ?l/litre ethylene accelerated abscission by 24-36 h in comparison with unfumigated controls. Diffusion of ethylene from distal fruitlet tissues to the abscission zone presumably triggers the events leading to abscission.