Comparative analysis of cytogenetic disorders in Triticum aestivum L. induced by soil xenobiotic and N-nitroso-N-methylurea

Aims. To determine the frequency and spectrum of the cytogenetic disorders, induced by a prolonged effect of the soil contamination with xenobiotic of the areas of the warehoused toxic wastes, and to identify the level of their mutagenic activity in comparison with the effect of the moderate and high concentrations of N-nitrozo-N- metylurea (NMU). Methods. The seeds of Triticum aestivum L., cultivars ‘Albatros Odeskyi’ and ‘Zymoiarka’, were grown in the soil samples of the ground of toxic wastes of “OrianaGalev Ltd.”, its re-cultivated plot and Dombrovskyi career dump of potash ores, situated near Kalush city, Ivano-Frankivsk region. To study the mutagenic activity of the moderate and high concentrations of NMU, seeds were kept in 0.005, 0.01, and 0.025 % water solution of supermutagen. The frequency and spectrum of the cytogenetic disorders in the cells of the root meristem of the shoots were defined by an ana-telophase method. Results. The frequency of the cytogenetic disorders, induced by genotoxicants of the soil near Kalush industrial district,exceeded the control level by 1.8–3.8 times. Under the effect of a low concentration of hexachlorobenzene in the soil together complex with available natural mineral compounds of mining-chemical raw material, the frequency of chromosome aberrations exceeded spontaneous indicators by 1.8–2.4 times. The spectrum of chromosome aberrations contained mostly acentric fragments; it was expanded due to the induction of the bridges, chromosome rings, and micro-nuclei, which were recorded under the effect of high NMU concentrations. Under the effect of hexachlorobenzene in the highest and the lowest concentrations, the indicator of the aberration number per aberrant cell, most likely, exceeded the control level statistically. Conclusions. The chemical soil contamination with hexachlorobenzene shows a high mutagenic activity, which, by the induction level of cytogenetic abnormalities, is almost equal to the mutagenic activity NMU in moderate concentrations. A chemical mutagenic factor in complex with natural mineral compounds of mining-chemical raw material keeps a high mutagenic activity even at low concentrations. A significant increase in share of cells with dicentric chromosomes in the spectrum of chromosome aberration types can indicate the radiomimetic properties of chemical genotoxicant. The increase in the number of cells with multiple aberrations shows the high genotoxicity of a chemical compound and the danger of facing serious genetic consequences in case the compound enters the environment.