Abstract
The present study was undertaken to study the effect of nicotinamide at different concentrations viz.0.5%, 1.0%, 1.5%, 2.0% on root meristems of Cyamopsis tetragonoloba L. Mitotic study reveals various types of chromosomal aberrations like scattering(C-metaphase), precocious, unorientations, laggard, stickiness, bridges etc. Among these scattering was most prominent followed by precocious movement at metaphase and stickiness at anaphase. The AMI is expressed in terms of RDR while the chromosomal abnormalities in terms of RAR. The RDR considerably became more negative and RAR was increased along with increasing doses of nicotinamide. Increase in the negative value of RDR was directly proportional to the severity of the mitotic inhibition. Thus it was found that along with increasing treatment doses of nicotinamide the total abnormality percent increased and the active mitotic index decreased which shows potential toxicity of nicotinamide at their higher doses in this plant.
