Cell cycle parameters and accumulation of metaphase cells in maize suspension cultures

Abstract

Cell cycle parameters of maize ( Zea maysL cv Black Mexican Sweet) suspension cultures and root meristem cells were determined by pulse labelling with [ 3H]thymidine ([ 3H]TdR). Total cell cycle time for the suspension cultures was 27 h; 3 h in G1, 14 h in S, 6 h in G2, 2.2 h in prophase, 1 h in metaphase, 0.1 h in anaphase, and 0.7 h in telophase. Cell cycle durations in root meristem cells of Black Mexican Sweet (BMS) corn with and without B chromosomes in vivo were 20.0 h and 18.3h, respectively. Chemical and physical methods were used successfully to accumulate mitoses in the suspension cultures; compared to the untreated control, the mitotic index of the treated cultures was increased from 4 to 23% and the frequency of metaphase cells increased dramatically from 3 to 19%.