Abstract: The genotoxic effects of cyclophsphamide (CP)in broad bean (Vicia faba)root tips were investigated. The results indicated that CP caused the mitotic index decrease, while the frequencies of abnormal cells, such as chromosomal aberrations (CA)including chromosomal segments, bridges and laggards, micronucleus (MN), nuclear buds and pycnosis, increased significantly in CP exposed roots.The number of cells with MN and pycnosis increased with the concentration of the treatments and the length of exposure periods.But the mitotic index had a negative response to the treated concentration and duration time.Our results indicated that the exposure to CP at lower concentrations for long duration can cause the same cytogenetic damage as at high concentrations for short exposure, so we should pay more attention to the occupational exposures.

Key words: cyclophsphamide, Vicia faba, genotoxicity, micronucleus, chromosomal aberration