Bulb Histogenesis in Hordeum bulbosum L.

The histological and associated histochemical phenomena occurring in the developing bud of Hordeum bulbosum were investigated. Naturally the bulb is formed by swelling of the lowest internode of the spike-bearing stern. Bulb initiation began by a rapid cell division followed by cell elongation. The bulb form was achieved by forming cell files directed diagonally outward in the upper part and by a periphery meristern contributing cells to the middle and the lower parts of the bulb internode. Starch accumulated in the cells before bulb initiation and was utilized completely only in the elongating cells when bulb elongation occurred. High content of nucleic acids and total protein, demonstrated by specific stainings, was observed in the cytoplasm of cells of the intercalary meristem at each internode. In the bulb, these stainings became progressively less as the bulb elongated.