Abstract
The development of the abscission zone in potato flower pedicels was compared between two cultivars. Cells of the abscission zone formed at the sepal-developing stage in 'May Queen', and the at petal-developing stage in 'Toyoshiro'. These cells were found initially in the epidermal and cortical regions of the pedicel. With the progress of flower bud development, cell division gradually spread to the vascular bundle region, and finally to the central parenchyma region of the pedicel. These results show that the formation of a protective layer starts earlier in the pedicels of 'May Queen' than it does in 'Toyoshiro'.
