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Summary A callus tissue culture of Corylus avellana L., isolated from the immature embryos and cultivated for two years on agar synthetic medium, was repeatedly found to be capable of somatic embryogenesis. In sections of the tissue, bipolar structures are interpreted as being globular to cotyledonary stages of embryoid development. 2,4-D did not inhibit the induction of embryoids, although it prevented their further development into plantlets. Electron microscopy of the tissue in active proliferation showed highly cytoplasmic cells rich in organelles and profiles of the endoplasmic reticulum. A characteristic feature of these cells is the presence of aggregated cisternae of the endoplasmic reticulum. They are often circular and bear ribosomes crystallized in tetramer units. Bundles of fibrous material are often found not only in the cytoplasm, but also in the nuclei. |
