Abstract: The ultrastructure of the cells from single cell to globular embryo stage in suspension culture were investigated. The amount and morphology of the organelles, especially the plastids spherosomes and protein bodies changed obviously during the embryogenesis. In embryogenetic clump stage there occured in the vacuolated cells direct nucleus division and peripheral cytoplasmic swelling. The vaeuolated cells returned to embryonic state quickly in this way. In this paper the physiological and biological significance of the ultrastructural changes of cells in different stages of somatic embryogenesis are discussed.

Key words: Peucedanum terebinthoceum, Cell culture, Somatic embryogenesis, Ultrastructure, Amitosis