Abstract
The abscission zone development of tomato pedicels on two cultivars were anatomically compared. In 'Tiny Tim Red', the initial meristematic cells of the abscission zone appeared during the sepal differentiation in the flower bud. The first detectable morphological change was an increase in cell division in the inner cortical parenchymatous region of the pedicel. These meristematic cells formed about 15-20 layers from the apical surface cells of the flower bud. As the flower bud developed, cell division of the abscission zone gradually spread to the vascular bundle and cortex region, and finally to the epidermal region of the pedicel. At anthesis, the abscission zone is composed of 6 to 8 layers of small cells which traverse the pedicel at the site of an indentation of the epidermis. In contrast to the 'Tiny Tim Red', 'Furikoma' pedicels are jointless (j2) and the meristematic cells of the abscission zone do not differentiate until anthesis.
