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 mu m(2) to 40000 mu m(2). 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 multinucleate cells were not observed in suspension with both nitrate and ammonium used as nitrogen source.