Growth, Cytology and Flow Cytometry of Embryogenic Cell Suspension Cultures of Panicum maximum Jacq. and Pennisetum purpureum Schum.
- Journal of Plant Physiology, 123(3), p.211-227, 1986 .
Embryogenic cell suspensions of Panicum maximum (4 year old)and Pennisetum purpureum (3 year old)continue rapid growth upon subculture without a marked lag phase. They have cell doubling times of 27 h and 32 h, respectively, during the exponential phase of growth. Maximum cell numbers of 2 × 10? cells · ml-1 are reached on about the eighth day of subculture in both species. Thereafter, cell lysis and death occur progressively. By day 16, 90 percent of P. purpureum cells appear non-viable. Flow cytometry of the cell suspensions showed that at any given time during the 8-9 day culture period, a majority of the cells are in G1 phase of the cell cycle, with substantial numbers cycling through the S and G2 phases. No marked change in this distribution pattern was seen in the first 8-9 days of growth during which the cultures did not reach stationary phase. Flow cytometry, microspectrophotometry and chromosome counts showed the cultures comprised predominantly ofnormal diploid cells.