Cell enlargement in suspension culture of carrot [Daucus carota L.Cv.Karo]. Preliminary studies

Cytological studies of Daucus carota L. (cv. Karo) in suspension culture were made. Cells growing on medium without ammonium were larger and more vacuolated than were cells grown on the standard medium. Their sizes (cell area) ranged widely from 200 µrm2 to 40000 µm2. They also showed a very low level of aggregation (1%) as compared to an 81% frequency of aggregates in the standard suspension. Suspension deficient in ammonium had a .small percentage of 2-9-nucleated cells. Such multlnucleate cells were not observed in suspension with both nitrate and ammonium used as nitrogen source.