HISTOLOGICAL AND CYTOCHEMICAL ASPECTS OF FLOWER BUD FORMATION IN APPLE
Before this histological differentiation, i.e. in apices still with vegetative structure, there are some cytochemical dissimilarities between apices induced and inhibited for flower initiation. Apices in buds under flower inductive conditions possess a higher relative level of DNA in the cell nuclei of the central meristem and apical axial zone, compared with apices in which flower initiation is inhibited.
Apices of buds from trees sprayed with ethephon to promote flowering showed similar, though less marked, changes in the pattern of DNA levels.