An Anatomical and Morphological Study of Abscission in Highbush Blueberry Fruit1

Abstract

Abstract Berry/pedicel abscission zone formation in cultivated highbush blueberry (Vaccinium corymbosum L.) during fruit ripening appeared at the distal portion of the transition zone (disc) separating the berry and the pedicel. The abscission zone was first evident as a compressed zone of cells at the periphery of the berry/pedicel junction in the immature green stage of berry development. Cell separation initially appeared during the green-pink berry stage concomitant with berry coloration. Separation was characterized primarily by cell wall rupture. No separation layer was formed through either the berry epidermis or the vascular bundles. The number of berries without attached pedicels separating from the cluster under applied force was closely related to the stage of ripening of the fruit. Stresses imparted during ripening by rupturing internal tissues are evident in definite morphological changes appearing on the surface of the fruit.