Effects of dinocap on the mitosis of Allium cepa L.

Abstract

Cytogenetic effects of dinocap were investigated in root tip cells of Allium cepa L. Mitotic index (MI), frequency of mitotic phases, mitotic and chromosomal abnormalities were determined in the presence of 0.00 (Control), 6.25 (EC50/4), 12.5 (EC50/2), 25 (EC50), 50 (EC 50X2), 100 (EC50X4) mg/l concentrations of dinocap at 12, 24 and 48 h treatment. 100 mg/l concentration was toxic in all treatment times. Mitotic index decreased significantly with increasing of concentration in all treatment periods as compared to their controls. However, dinocap has not induced significant effect on the percentage of the mitotic stages except 25 and 50 mg/l at 48 h. This fungicide induced stickiness, C-mitosis, bridges, laggards, multipolarity, polyploidy, fragments, micronuclei and binucleated cells. In addition, in pretreated root tips, chromosome breaks, fragments, tetraploidy and sister union were detected. © 2005 The Japan Mendel Society.