title: Clastogenicity of pentachlorophenol, 2,4-D and butachlor evaluated by Allium root tip test.
abstract: The meristematic mitotic cells of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. For assessing genotoxicity of pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor), 50% effective concentration (EC(50)), c-mitosis, stickiness, chromosome breaks and mitotic index (MI) were used as endpoints of genotoxicity. EC(50) values for PCP and butachlor are 0.73 and 5.13 ppm, respectively. 2,4-D evidently induced morphological changes at higher concentrations. Some changes like crochet hooks, c-tumours and broken roots were unique to 2,4-D at 5-20 ppm. No such abnormalities were found in PCP and butachlor treated groups, however, root deteriorated and degenerated at higher concentrations (<3 ppm) in PCP. MI in 2,4-D showed a low average of 14.32% followed by PCP (19.53%), while in butachlor it was recorded 71.6%, which is near to the control value. All chemicals induced chromosome aberrations at statistically significant level. The highest chromosome aberration frequency (11.90%) was recorded in PCP at 3 ppm. Large number of c-mitotic anaphases indicated that butachlor acts as potent spindle inhibitor, whereas, breaks, bridges, stickiness and laggards were most frequently found in PCP showing that it is a potent clastogen.
authors.affiliation: Gene-Tox Laboratory, Division of Genetics, Department of Zoology, Aligarh Muslim University, 202002, UP, Aligarh, India.
authors.forename: Bushra
authors.initials: B
authors.lastname: Ateeq
authors.forename: M
authors.initials: M
authors.lastname: Abul Farah
authors.forename: M
authors.initials: M
authors.lastname: Niamat Ali
authors.forename: Waseem
authors.initials: W
authors.lastname: Ahmad
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity*; D000083:Acetanilides / Q000633:toxicity*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants; D006540:Herbicides / Q000633:toxicity; D006801:Humans; D018519:Meristem / Q000166:cytology / Q000187:drug effects; D008940:Mitotic Index; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000633:toxicity*; D019697:Onions / Q000033:anatomy & histology / Q000187:drug effects* / Q000235:genetics; D010416:Pentachlorophenol / Q000633:toxicity*
chemical_list: D000083:Acetanilides; D004785:Environmental Pollutants; D006540:Herbicides; D009153:Mutagens; D015084:2,4-Dichlorophenoxyacetic Acid; C054409:butachlor; D010416:Pentachlorophenol