The direction of selection of genetically heterogeneous cell populations ofDioscorea deltoidea Wall

The initial strain ofDioscorea cell culture is characterized by a double-peak curve of mitotic activity, by dominance in the population of meristematic cells, by a great variety in the number of chromosomes and also by polyploidization in the process of cultivation. After treatment with different doses of N-nitroso-N-methylurea (NMU) physiological parameters of the cell populations were found to change (dynamics of mitotic activity, ratio between types of cells). On passaging, physiological differences between the strains are levelled up. The studied strains are characterized by different directions of cell selections,i.e. the control strain — towards polyploidization, and in NMU treated strains are stabilized on di- and triploid levels.