Cytotoxic effect of herbicides “Uragan” and “Oberig” on root meristems of Allium cepa and Allium porrum

The work presents the results of a study of the cytotoxic effect of the herbicides “Uragan” and “Oberig”.The aim of the work was to study the character and frequency of mitosis disorders and chromosomal aberrations induced by these herbicides. The object of the study were the cells of the apical meristems of roots of two speciesof plants of the genus Allium: Allium cepa L. and Allium porrum L. The experiment used 0.1 %, 1 % and 2 % solutions of the herbicide “Uragan” (active ingredient – glyphosate) and 0.08 %, 0.75 % and 1.5 % solutions of the herbicide “Oberig” (active ingredient – khizalofop-P-ethyl). The seedlings were exposed to 24 and 48 hoursof exposure in the solutions. Cytogenetic analysis was performed using the standard Allium test method. As a resultof the study, changes in the organization and morphology of chromosomes were observed in the root tip cells of both species. Chromosomal aberrations were recorded at different stages of the cell cycle, including binucleated cells, micronuclei, bridges, chromosome fragments, chromosome lag, anaphase delay, and k-mitosis. The totalnumber of chromosome aberrations increased with increasing herbicide concentration and exposure time. Themaximum values were observed at 48-hour exposure in a 2 % solution of the herbicide “Uragan” and a 1.5 % solution of the herbicide “Oberig”. At the same time, a species-specific response to the stress factor is observed.The frequency of mitotic pathologies in Allium cepa cells is higher under the influence of “Uragan”, while Allium porrum cells showed greater sensitivity to “Oberig”. The herbicides “Uragan” and “Oberig” showed a cytotoxic effect on root cells of both onion species, which was manifested in an increase in the number of cells with pathologicalprocesses or structures. The most common anomalies were the appearance of micronuclei and binucleation. Thedependence of the type of disorders on the chemical nature of the herbicide was revealed. The results obtained confirm the cytotoxic potential of the studied herbicides and indicate the need to take into account the species- specific characteristics of plants when assessing their sensitivity to agrochemicals.