AMITOSIS IN THE LEAVES OF NICOTIANA TABACUM L. AND LYCIUM BARBARUM L. DURING TISSUE CULTURE STUDIES ON AMITOSIS OF EPIDERMAL CELL AND SPECIAL EFFECT OF 2, 4-D IN THIN CELL LAYER CULTURE OF Begonia rex-cultorum Suspension Culture of Endosperm Callus Cell and Amitosis In Vitro Ultrastructure of the Cell of Peucedanum terebinthaceum in Different Stages of Embryogenesis in Suspension Cell Culture Mitosis and Amitosis of Generative Cell Nuclei in Artificially Germinated Pollen Tubes in Zephyranthes candida(Lindl.)Herb. DYNAMIC CHANGES OF THE GENERATIVE CELL AND THE VEGETATIVE NUCLEUS IN ARTIFFICIALLY GERMINATED POLLEN TUBE IN LIRIOPE SPICATA LOUR