Development of the Abscission Zones in j-2in Pedicels of Galapagos Wild tomatoes.

The abscission zone development in the pedicels of Galapagos wild tomatoes with j-2in gene was investigated anatomically by comparing it with that of a normal pedicel that forms the complete abscission zone. In normal pedicel, cells of the abscission zone formed initially when sepals were differentiating during flower bud development ; in j-2in pedicel, they were formed at a later stage. In a normal pedicel at anthesis, the cells of the abscission zone were small, diskshaped, and the epidermal tissue adjacent to the abscission zone was concave significantly toward the inner cortex. In contrast, in j-2in pedicel at anthesis, cells of the abscission zone were composed of isodiametric cells and the epidermal tissue was slightly concave. These results suggest that the j-2in gene delays abscission zone formation and development.