LONG-TERM SUSPENSION-CULTURE OF TRITICUM-TIMOPHEEVII CELLS - 3 - SYNCHRONIZATION OF CELL DIVISIONS WITH HYDROXYUREA AND COLCHICINE

Cell divisions in Triticum timopheevii (Zhuk.) Zhuk. suspension cultur e were synchronized by successive treatments with hydroxyurea and colc hicine, with the best results achieved at their respective concentrati ons of 1mM and 0.05%. At higher concentrations, hydroxyurea was toxic to wheat cells and considerably decreased the mitotic index when compa red to untreated cells. The extent of synchronization depended on the initial cell proliferation activity and increased with a higher initia l mitotic index. The frequency of chromosome rearrangements was also h igher in hydroxyurea-treated cells, the number of deletions increased, and the spectrum of chromosome modifications expanded.