Cytological effects of pesticides XV. Effect of the insecticide Methamidophos on root-mitosis of Vicia faba.

Abstract

The effect of the insecticide O, S-dimethyl phosphoramidothioate (Methamidophos) has been studied on root-mitosis of Vicia faba. Two types of treatments were conducted: seed-soak-treatment for 24 hours and root-treatment for 4 hours. Different concentrations of the insecticide ranging from 500 ppm to 31.25 ppm have been used in each treatment.The insecticide showed no significant effect on the mitotic index, meanwhile it induced a highly significant percentage of cells with chromosome aberrations after both seed-soak- and root-treatments. Roots treated with 500 ppm of Methamidophos recovered after replacement in water for 48 hours.Disturbed meta- and anaphases where the chromosomes spread irregularly over the cell dominated. Other abnormalities e.g. chromosome stickiness, lagging chromosomes and chromosome fragmentation were observed.