Evaluation of the Cytogenotoxic Effects of Emulsifiable Concentrate form of Amitraz Pesticide on <i>Allium cepa</i> L

Abstract

The cytogenotoxic effects of emulsifiable concentrate of amitraz pesticides was evaluated using Allium cepa L. test. The root meristems of A. cepa L. were treated with five concentrations (1%, 5%, 10%, 20% and 40%) of the chemical pesticide at 48 h for cytogenetic analyses and 96 h for root length inhibition. Pesticide doses affected root length significantly (P<0.05) at 5% to 40%; with 50% effective concentration (EC50) value of 18% while there was no significant difference between control and 1% (p>0.05). The mean root length of the treated A. cepa for Amitraz pesticides in all concentrations was lower compared to the control showing the obvious mitodepressive effects of amitraz pesticides. A dose dependent reduction in the total mitotic dividing cells and mitotic index was observed in A. cepa treated with the pesticides. The values of mitotic index obtained for amitraz pesticides at 5% (5.20), 10% (4.0), 20% (2.30) and 40% (0.80) were lower than half of the negative control (7.25), which reflect its cytotoxicity. All the concentrations of the pesticides used in the present study induced important abnormalities during mitotic division. These aberrations were: chromosome stickiness, disturbed spindle, anaphase and telophase bridges, chromosome fragments, laggard chromosomes, and c-Mitosis. The highest abnormality number was observed in the root tips of Allium cepa (5%) while the least was at 40%. Frequencies of chromosome abnormalities were low at 20% and 40% concentration because of damaged cell and lower cell divisions. The present study, showed the inhibition of growth and induction of chromosomal aberrations by amitraz, this suggest their capability in inducing cytotoxicity and genome instability.

The insecticide spirotetramat may induce cytotoxic and genotoxic effects on meristematic cells of <i>Allium cepa</i> L. and <i>Vicia faba</i> L.

“…Also, it caused abnormal segregation of chromosomes so that different chromosomal abnormalities were formed, the most frequent being multipolar, break, stickiness, vagrant, bridge, c-mitosis, and micro-nucleus. Similar genotoxic results are obtained in studies conducted on pesticides acting as genotoxic and mutagenic agents (Adesuyi et al 2018, Kumari et al 2020, Macar 2021. Analysis of the data showed that the most frequent CAs were multipolar anaphase.…”

Chromosomal aberrations induced by Mitomycin C in canine lymphocytes

“…It has been reported that this may be due to the failure to separate the chromosomes, due to the loss of the Ki-67 protein (BRANGwyNNE and MARKO, 2016). It could also be interpreted as the result of DNA depolymerization, partial dissolution of nucleoproteins, breakage and exchanges of the folded chromatid fiber, and the removal of non-histone proteins from the chromosomes (ADESUyI et al, 2018). These are entities in which the chromosomes are not free, but are united by a thin filament.…”

“…Those metaphases that presented no more than 4 overlapping chromosomes and differed in no more than 2 centromers (MOSESSO et al, 2013) from the diploid number of the species (2n=78) were analyzed. In each metaphase, the following observations were recorded: chromatidchromosome gaps (ctg-csg) and breaks (ctb-csb), acentric fragment (ace), telomeric association by a chromatid-chromatid-association (at1), telomeric associations (at), deletions (del), pulverized metaphase (pvz), endoduplicated metaphase (end), early chromatid segregation (seg) (UDROIU and SGURA 2017) and sticky (sti) chromosomes (ADROvIĆ et al, 2016;ADESUyI et al, 2018). The results are expressed as the frequency of each variable analyzed/100 cells.…”