Le développement de l'embryon zygotique chez Vitis vinifera L.

The development of the zygotic embryo of Vitis vinifera L.The embryonic development of Vitis vinifera from the zygote to the mature embryo has been studied. The planes of early cell divisions are irregular, thus leading to formation of a large globular proembryo comprising about 1500 undifferentiated cells above a bulky suspensor. Organogenesis of the embryo sta rts with initiation of the cotyledons and constitution of the radicular meristem. The intercotyledonary zone, future shoot apex, is formed by about 300 cells. In this zone, cells remain undifferentiated throughout embryogenesis; its organization begins to be completed only after germination. The radicular meristem, on the other hand, is functioning from the embryonic stage. The meristem of the embryonic radicle and the meristem of the adventitious root are identical in their ('open' type) organization