Evaluation of clastogenicity of 4, 6-dinitro-o-cresol (DNOC) in allium root tip test

Abstract

4, 6-Dinitro-o-cresol (DNOC) is a pesticide, fungicide and insecticide, used in agriculture. In this research the genotoxic effect of DNOC on the root tips of Allium cepa L. was determined. The correlations between the effects of different concentrations, exposure times on the mitotic index (MI) and induction of chromosomal aberrations (CA) were also examined. Experiments were carried out in duplicate, using aqueous solutions of DNOC to concentrations of 250 and 500 ppm, at intervals of 0, 3, 6, 12, and 24 h. The results revealed an inhibition of the MI at the highest concentration and experiment times; this is an evidence of cytotoxicity of DNOC. Large number of c-mitosis indicated that DNOC acts as a strong spindle inhibitor, whereas, other CA types such as, breaks, bridges etc. were found in all tested concentration and times (p < 0.001) showing that is a potent clastogen.