CYTOLOGICAL EFFECT OF TANNERY EFFLUENTS ON ROOT-MERISTEMS OF ALLIUM-CEPA LINN TEST SYSTEMS

Water samples were collected from effluent canal (Sample I), point of mixing of effluent with irrigation canal (Sample II) and downstream ca nal (Sample III), Toxicity of these samples on mitotic activity of All ium cepa root meristem was tested. Samples affected the mitotic indice s and induced mitotic aberrations. Sample I was more toxic than other samples. Even though, Sample III showed moderate toxicity, recovery wa s not achieved. The toxicity was proportionate to the dose concentrati on. Mitotic aberration exhibited clastogenic effects more than turbage nic effects. Generally observed mitotic abnormalities are bridge forma tion, fragmentation, disintegration, binucleate, bimetaphase, bianapha se, laggards and micronuclei formation.