Genotoxic Effects of Herbicide Illoxan (Diclofop-Methyl) on Allium cepa L (original) (raw)
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Cytogenetic effects of different herbicides viz. Atrazine, Avenoxan, Diuron and Quizalofop-P-ethyl (QPE), were evaluated in the root tip meristem cells of Allium cepa. In the Allium root growth test, the effective concentration (EC 50) value was determined as approximately 0.5 ppm in the case of Atrazine and Avenoxan and 1.0 ppm in the case of Diuron and QPE herbicides with a control for each combination. Mitotic index decreased with increasing herbicide concentration at each exposure time. In anaphase-telophase cells, the total percentages of different chromosomal aberrations like stickiness, bridges, break(s), ring chromosomes, vagrant chromosomes, c-mitosis, delayed anaphase, laggard(s) and micronuclei at high concentration (1 ppm) were calculated as 31.85% (Atrazine), 29.94% (Avenoxan), 36.66% (Diuron) and 41.04% (QPE). The total number of chromosome aberrations increased as herbicide concentration increased. Micro-nucleated cells were observed at different stages of the cell cycle. The frequency of the micronucleus was markedly higher at 1 ppm than at other test concentrations.
Caryologia, 2008
Cytogenetic effects of phenoxy herbicide viz. quizalofop-P-ethyl (QPE, ethyl (R)-2-[4-[(6-chloro-2quinoxalinyl)oxy]phenoxy] propionate) were evaluated in the root meristem cells of Allium cepa. In the Allium root growth test, the effective concentration (EC 50) value was determined as approximately 1.5 ppm. Cytological experiments were carried out using QPE concentrations of 0.75 (EC 50 /2), 1.5 (EC 50) and 3 ppm (EC 50 x2) at 24, 48, 72, and 96 h, with a control for each combination. Mitotic index decreased with increasing the herbicide concentration at each exposure time. In anaphase-telophase cells, the total percentages of stickiness, bridges, vagrant chromosomes, c-anaphase, multipolarity, and fragments according to total cells with chromosome aberrations were calculated as 38.57, 28.42, 16.67, 14.10, 1.60, and 0.64%, respectively. The total chromosome aberrations increased with an increasing the QPE concentration. Micronucleated cells were observed at interphase. The frequency of the micronucleus was markedly higher at 3 ppm compared to other test concentrations.
Cytological effects of the herbicide racer “flurochloridone” on Allium cepa
Caryologia, 2003
The present investigation was carried out to study the cytological effects of the herbicide racer "flurochloridone" (3-chloro-4-(chloromethyl)-1-[3-(trifluoromethyl)= phenyl]-2-pyrrolidinone) on Allium cepa with respect to the cell response, mitotic index, mitotic abnormalities and chromosome aberrations. The roots of bulbs were treated with the following concentrations depending on the root growth inhibition test: 80 ppm (LD 50 ), 40 ppm (LD 50/2 ) and 20 ppm (LD 50/4 ). The results indicated that flurochloridone herbicide reduced the mitotic division in A. cepa as compared to their control groups. The reduction in mitotic activity was more significant when the concentration of the herbicide increased and the exposure time was prolonged. The treatment conducted with flurochloridone induced a significant percentage of abnormal mitosis. Seven types of abnormalities were recorded: C-metaphase, laggards, stickiness, bridges, fragments, multipolarity and poliploidy. Micronucleated cells were also observed at interphase. In additon, in pretreated root tips, chromosome breaks, fragments and sister union were detected.
Journal of Natural Sciences Research, 2014
Pesticides possess biological activity including genotoxic influence and can affect non target organisms. The cyto-and genotoxicological potency of wide-spec (Abamectin+Emaamectin benzoate) pesticide was screened using Allium cepa L. test. Onion roots were exposed for 24 h to ten concentrations (0, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1ml.L-1) of pesticide and 8 gm.L-1 of cyclophosphamide as positive control. Some microscopic endpoints as: mitotic indices and chromosomal aberration types were evaluated. The results showed obvious concentrationdependence. Mitotic index decreased from 21.77% (negative control) to 11.97% (dose of 1.00). Abnormal cell's frequency was considerably increased, too. Root growth retardation was significant due to different doses. Physiological and clastogenic types of chromosomal aberrations, as: lagging, fragments, granule, bridges, polyploidy, stickiness, and micronuclei chromosomes were observed in all corresponding concentrations. Data of this study showed that analyzed pesticide (commonly used in Iraqi agriculture) can potentially induce cytotoxic and genotoxic effects on crops and ultimately damage biota and human health.
Plants are direct recipients of agro – toxics and therefore important materials for assessing environmental chemicals for genotoxicity. The meristematic mitotic cells of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. Onion root tips were grown on moistened filter paper in petri dish at room temperature. Germinated root tips were then exposed to three concentrations of each pesticide for 24 h. About 1 – 2 mm length of root tip was cut, fixed in cornoy’s fixative, hydrolyzed in warm 1 N HCL, stained with acetocarmine and squashed on glass slide. About 3000 cells were scored and classified into interphase and normal or aberrant division stage. Cytotoxicity was determined by comparing the mitotic index (MI) of treated cells with that of the negative control. The MI of cells treated with Dichlorophen and Dichlorovos at one or more concentration was half or less than that of control are said to be cytotoxic. Genotoxicity was m...
Cytotoxic and Genotoxic Effects of Clopyralid Herbicide on Allium Cepa Roots
Research Square (Research Square), 2021
Clopyralid is a one of the synthetic pyridine-carboxylate auxin herbicides and used to control perennial and annual broadleaf weeds in wheat, sugar beets and canola etc. In this study, dose dependent cytotoxicity and genotoxicity of clopyralid at different concentrations (25, 50, and 100 µg/mL) on the Allium cepa roots were evaluated at macroscopic (root growth) and microscopic levels (Mitotic index (MI), chromosome aberrations (CAs) in ana-telophase cells and DNA damage) using root growth inhibition, Allium ana-telophase and comet tests. The percentage root growth inhibition and concentration reducing root growth by 50% (EC 50) of clopyralid in relation to the negative control were determined by using various concentrations of clopyralid (6.25-1000 µg/L). The 96 h EC 50 of clopyralid was recorded as 50 µg/L. The gradual decrease in root growth and the MI reveals the cytotoxic effects of clopyralid. All the tested concentrations of clopyralid induced total CAs (polyploidy, stickiness, anaphase bridges, chromosome laggards, and disturbed ana-telophase) and DNA damage dose and time dependently. This study con rmed cytotoxic and genotoxic effects of clopyralid on non-target organism.
Cytological Effect of the Herbicide 2,4-D isooctylester 48% on Root Mitosis of Allium cepa
CYTOLOGIA, 2000
The effect of the herbicide 2,4-D isooctylester 48% (Esteran 48) has been studied on root mitosis of Allium cepa. Root tips of Allium cepa were treated with a series of concentrations, ranging from 50 ppm to 50,000 ppm for 3, 6, 12, 24 h. Examinations of roots were done in permanent root tip squash preparations stained by the Feulgen technique. Esteran 48 effects the relative duration of each mitotic stage as compared with the control. It also caused reduction in the mitotic index, indicating mitotic inhibition, and increased in the frequency of abnormal mitosis. The type of the abnormalities induced: chromosome stickiness, C-metaphase, tetraploid cells, bridges, laggards, tripolar anaphases-telophases and micronuclei. The effect of Esteran 48 on root mitosis simulates that of colchicine in the type of abnormal metaphase (C-mitosis) and induction of polyploidy cells as well as the accumulation of metaphases. Key words 2,4-D isooctylester, Chromosome abnormalities.
Pesticide Biochemistry and Physiology, 2005
Combined cytogenetic and ultrastructural effects of substituted urea herbicides-isoproturon (ISO) or diuron (DIU) and a synthetic pyrethroid insecticide-deltamethrin (DEL) were examined in the root meristem cells of Allium cepa. For cytogenetic analysis root meristem cells were exposed to the mixtures of ISO (25 or 50 ppm) or DIU (20 or 40 ppm) and DEL (0.25 or 0.5 ppm) for 6 h and analyzed at 24 or 48 h post-exposure whereas for ultrastructural studies roots were exposed for 6 or 24 h to similar concentrations of combinations and examined. Both the combinations, ISO + DEL or DIU + DEL, were found to induce chromosomal breaks and variety of mitotic aberrations at 24 and 48 h post-exposure. The combinations containing higher concentration of DEL (0.5 ppm) induced statistically significant (p < 0.001) frequencies of aberrations than that of the combinations containing low concentration of DEL (0.25 ppm). Chromosome aberrations in all the treatment groups were less frequent than that of mitotic aberrations. Electron microscopic study revealed drastic alterations in the membranous organelles like concentric arrangement of endoplasmic reticulum, crescented or circular structure of Golgi complex dictyosomes and swollen mitochondria. Further, the combination of DIU + DEL appeared to be more toxic than that of ISO + DEL. Present findings suggest that the coexistence of ISO or DIU and DEL in plants synergies the toxicity inducing drastic ultrastructural alterations which are different from its independent effects reported earlier.
Sift Desk Journals, 2016
Atrazine is an herbicide that causes serious damage to the environment and possibly affects the genetic material of organisms that come into contact with this agent, provoking mutations in their DNA. Although the herbicide Atrazine has been tested by various systems, a large number of deficiencies have been reported for many assays, and some evidence of its genotoxic effects still needs to be confirmed. The objective of the present study was to evaluate the herbicide Atrazine effects, analyzing the mitotic index alterations and the induction of chromosome aberrations, using the Allium cepa test system. Fifty Allium cepa seeds were used for germination in Atrazine solutions at the concentration used in the field (0.125 ppm) and at progressively lower concentrations (0.062, 0.031 and 0.015 ppm). After 20 h, some roots were then collected from each assay, while the remaining roots were transferred to plates containing Milli-Q water and allowed to recover for 48 h. The herbicide reduced the germination indexes of seeds, the mitotic indexes of cells and induced alterations in the genetic material of the test organism, what suggests that this herbicide presents genotoxic effect at all concentrations tested.