Biomarker-based evaluation of cytogenotoxic potential of glyphosate in Vigna mungo (L.) Hepper genotypes.

Herbicides have proven to be a boon for agricultural fields. Their inherent property to kill weeds and unwanted vegetation makes them an essential biological tool for farmers and agricultural systems. Besides being capable of destroying weeds, they also exhibit certain effects on non-target crop plants. In the present study, a laboratory experiment was performed to assess the effect of glyphosate on Vigna mungo root meristem cells. Seeds of five different genotypes of V. mungo were treated with a series of concentrations of glyphosate ranging from 1 to 10 mM, and their effects on mitotic cell division were studied. Healthy and uniform-sized seeds were selected and were allowed to grow in Petri plates for 3 days, and all the doses were maintained in triplicates. Roots were fixed at day 3 after treatment (DAT) for cytological microscopic slide preparation. The results obtained indicate the dose-dependent reduction in the mitotic index in all the genotypes and an increase in the percentage of chromosomal aberrations (CAs) and relative abnormality rate (RAR). Most commonly observed chromosome aberrations at lower doses (< 6 mM) were fragments, stickiness, and disoriented metaphase, while at higher doses (6 to 10 mM) bridges, laggards, spindle disorientation, and clumping were obvious. The increase in the percentage of CAs and RAR indicates the inhibitory effect of glyphosate on cell cycle progression at various stages in root tip cells. The present study is a fine example of a biomarker-based genotoxic assessment of mitotic damage caused by glyphosate.