An Anatomical and Histochemical Study of Abscission in Maturing Sweet Cherry Fruit

Abstract

Abstract Abscission of maturing sweet cherry fruit (Prunus avium L. cv. Windsor) occurred at 2 different abscission zones, depending on the stage of fruit development. Immature fruit abscised at the upper zone between the pedicel and peduncle; mature fruit abscised at the lower zone between the fruit and receptacle. Separation in the abscission layer began directly above the stony pericarp and resulted in the formation of a cavity. Later separation occurred at the fruit : pedicel indentation and extended through the abscission layer toward the vascular bundles. Abscission involved the fracturing of cell walls as well as wall separation. There was no evidence of change in pectins, cellulose or other polysaccharides in the cell walls of the abscission layer prior to or during fruit separation. No starch accumulation in the abscission zone or lignification of tissue adjacent to the abscission layer was observed through fruit maturity.