Cytogenetic response of hexavalent chromium-induced somatic cell abnormalities in Allium cepa

Abstract

Hexavalent chromium present in water inhibited root growth due to its toxicity and its accumulation in roots. The Cr (VI) concentration in water samples ranged from 0.003 to 0.750 mg/l in and around the Sukinda valley, which was higher than the Government permissible limit. The Cr (VI)-containing water was utilized by local inhabitants for drinking and agricultural practices which produced increases in human health hazards and mutations or cell death in plants. The cytological effect of hexavalent Cr was investigated using onion roots grown in chromium contaminated water samples. The most pronounced chromosome aberration(s) encountered was stickiness followed by bridges with or without fragments, chromosomes with inactivated centromeres, variations of C-mitosis, vagrant chromosomes and micronuclei. The presence of C-mitosis appeared to be due to complete inhibition of spindle fibres. Mitotic chromosomal abnormalities were more numerous and death to the cell occurred at higher concentrations. Local inhabitants were advised not to drink the Cr-contaminated water nor to eat below ground plant parts.