Fig. 1.

Histology of barley androgenic embryos at different stages of development. a Except for their basal part (white arrow), embryos at the early globular stage possessed one layer of protodermal cells. Underneath the protodermis, cells with large vacuoles and many starch grains were visible. b At a later globular stage, a zone of dividing cells was present in the centre of the embryo. c At the transitional stage, the scutellum (sc) and coleorhiza (col) were visible. A zone of dividing cells (ellipse) was located in the ventral–basal part of the embryo. d At the coleoptilar stage, the coleoptile (co), shoot meristem (sm), scutellum (sc), and coleorhiza (col) were present. d dorsal side of the embryo, p protodermis, v ventral side of the embryo, zdc zone of dividing cells. Longitudinal sections through embryos stained with PAS + toluidine blue. Bars = 50 μm