Ultrastructure of the cuticle during growth of the grape berry ( Vitis vinifera L.)

The outer surface morphology and the ultrastructure of grape berries during growth were examined by electron microscopy. The cuticle began to form before anthesis as highly organized and tightly appressed cuticular ridges. During the period of rapid expansion, the cuticular material spread out over the grape berry. At the same time, an outer wax layer of about 0.5 μm was indentified. As growth proceeded, the cuticular material flattened out and eventually disappeared. At the final stage of growth, the berry had a smooth, continuous and homogeneous cuticle with a thickness of 3 μm.