Cytogenetic monitoring of spontaneous mutagenesis

Abstract

Due to the challenging environmental situation in Ukraine, there is a need for cytogenetic monitoring, establishing cause-and-effect relationships, and assessing the toxic-mutagenic activity of environmental components. The results of such monitoring can serve as a basis for developing rehabilitation measures aimed at improving the environmental condition. Cytogenetic bioassay methods allow the evaluation of ecological and genetic risks to biota, considering the overall impact of pollutants, predicting changes in ecosystems, and making timely management decisions to improve environmental quality and preserve the nation’s gene pool. The article provides cytogenetic monitoring of apical meristems of the roots of Raphanus sativus subsp. radicula (Pers.) DC. and Allium cepa L. seedlings., grown on soils of residential areas, and the effect of ions of some elements on the cytological parameters of Pisum sativum L. was studied. It was noted that the spectrum of mitosis abnormalities and chromosome aberrations was expanded due to lagging chromosomes and micronuclei. Residential areas with a consistently high level of spontaneous cytogenetic disorders require the development of a local monitoring system to identify genetic hazards. The research on the proliferative activity of apical meristem cells confirms the hypothesis of aluminum toxicity to plants. Cytotoxic effects are assessed at the micro- and macroscopic levels. Macroscopically, reduced root growth of bioindicator plants was observed, which may result from several possible mechanisms: cell death, inhibition of division, cell elongation, or nutrient absorption. It was found that the duration of the prophase is directly influenced by the mobile forms of Zn and Pb, while Cu has a reverse effect. According to the results of multiple regression analysis, the most significant influence on these processes is exerted by the mobile forms of Zn, Cu, and Pb in the surface layers of the soils of the studied residential areas. Under the influence of AlCl3, the proportion of cells in the anaphase stage increases; CdCl2 affects the prophase stage; Na2SeO3 affects the meta- and anaphase stages; X-ray irradiation affects the telophase stage. Regarding the ability to induce the frequency of aberrant anaphases, a ranking can be constructed: Na2SeO3 (3.75·10–6 M) > AlCl3 (3.86·10–5 M) > CdCl2 (8.44·10–5 M). A radiation dose of 9.03·10–3 C/kg leads to the frequency of chromosomal aberrations, similar to the effects of AlCl3 (3.86·10–4 M) and Na2SeO3 (8.34·10–6 M). High concentrations of aluminum are associated with an increase in anaphases with fragments and two to three bridges.