Abstract: The morphogenesis of explants cultured in vitro was affected by three different antibiotics, i.e.Carbenicillin, Claforan, and Keflodin.All of them showed an unfavorable effect on microspore embryogenesis in isolated microspore culture of Brassica napus cv.Topaz.For Carbenicillin, within the range of 0-500mg/L, the higher the concentration, the less the embryos were produced.The best concentration of Carbenicillin seemed to be 50mg/L for inhibiting bacteria growth and achieving favourable production of embryos.Carbenicillin also had some stimulative effects on callus formation of pepper cotyledon explants, and on rooting of regenerated plants resulting in shorter and thicker roots or even roots with tumors.

Key words: Antibiotics, Plant culture iu vitro, Morphogenesis