Genotoxicity of cadmium on root meristem cells of Allium cepa: cytogenetic and Comet assay approach

Cytogenetic and DNA damaging effects of cadmium (Cd) were examined through chromosome aberrations (CA) and Comet assay on the root meristem cells of Allium cepa. Root meristem cells were exposed to Cd (10, 20, and 40 μM) for 24 h and also left in water for 24 h recovery. Exposure of Cd revealed significant (P<0.001) inhibition of mitotic index (MI), induction of CA, mitotic aberrations (MA), and micronucleus (MN) formation. Similarly, at 40 μM significant increase in the tail length (85.70±9.40 μm) and tail moment (58.75±5.30 μm) was observed as compared to control 4.50±0.76 and 0.86±0.03 μm, respectively. However, cells examined at 24 h post-exposure showed concentration-dependent decline in all the endpoints. Findings of this study confirms the root meristem cells of A. cepa are suitable model for detecting both the environmentally induced CA as well as DNA damage analyzed by Comet assay.