ВЛИЯНИЕ ПЛОТНОСТИ КУЛЬТУРЫ НА ПОЛОВОЕ ВОСПРОИЗВЕДЕНИЕ ARDISSONEA CRYSTALLINA (BACILLARIOPHYTA)

It is well-known that one of the key factors which affect the sexual reproduction of diatoms is the cell concentration in cross-cultures. The concentration of pheromones which probably initiate gametogenesis in the mixture of cells of opposite sexes, depends on the culture density. The influence of the cell concentration on the sexual reproduction has been studied in the experiments with taxonomically important marine diatom Ardissonea crystallina (C. Agardh) Grunow. Several clones have been isolated from samples taken near Sevastopol (the Black Sea). The cell concentration which is most favorable for the species reproduction has been estimated. Low initial density may also increase the time required to start heterothallic sexual reproduction. The optimum cell concentration which is most favorable for the species reproduction has been calculated. Bigger volume of the medium allowed reproduction at higher cell concentration. If the initial concentration of cells was greater than optimal density, the reproduction often did not occur, probably due to cell metabolism products accumulated in the culture.