Rape embryogenesis. II. Development of embryo proper

Abstract

It was found in the continued studies on rape embryogenesis, started by the description of the proembryo (Tykarska, 1976) that the development of embryo is extremely regular and based on differentiating divisions. It appeared that the transverse segmentation boundary and cell walls separating the mother cells of the histogens in the proembryo can be distinguished in all the later stages of the embryo. The border between the cytoledons and epicotyl part of the embryonal axis, and the hypocotyl corresponds to the segmentation boundary between layer l and layer l' at the octant stage. As border between the hypocotyl and radicle was assumed the upper boundary of the root cap reaching usually to the level of the boundary between segments II and III of dermatogen and periblem. The apical meristem of the shoot forms from dermatogen and the periaxial cells of the globular embryo subepidermis. The promeristem of the radicle constists of 3 layers of initial cells surrounding on all sides the inactive layer of central binding cells.