Cytogenetic and genotoxic effects of 2-chlorophenol on Allium cepa L. root meristem cells

2-Chlorophenol (2-CP), an organic pollutant, is used as intermediate in the synthesis of the higher chlorinated congeners, certain dyes, preservatives, herbicides, fungicides and plastics. In this study, cytotoxic and genotoxic effects of 2-CP were investigated on the root meristem cells of Allium cepa for its effects on root growth, mitotic index (MI), mitotic phases, chromosomal abnormalities (CAs) and DNA damage by using Allium anaphase-telophase and Comet assays. EC50 of 2-CP value was determined as approximately 25 ppm by Allium root growth inhibition test. Three concentrations of 2-CP (12.5, 25 and 50 ppm), distilled water (negative control) and methyl methane sulphonate (MMS, 10 ppm, positive control) were applied to onion stem cells under different exposure periods (24, 48, 72 and 96 h). All the applied doses of 2-CP slightly decreased MIs. 2-CP induced total CAs such as disturbed anaphase-telophase, chromosome laggards, stickiness and bridges and also DNA damage at significant levels. These results demonstrate that 2-CP has genotoxic effects in A. cepa root meristematic cells.