The presence of synthetic auxins (2,4-D at a concentration as low as of 0.5 to 5.0 mg I-1, NAA at least at 5 mg I-1) in the cultivation medium was essential for the induction of callogenesis in anther cultures ofZea mays L. The application of IAA was ineffective. Kinetin induced bursting, darkening and a rapid anther necrosis, but at an appropriate concentration ratio with 2,4-D it stimulated pollen maturation at the same time.