Effect of Chlorthal Dimethyl on Oat and Foxtail Seedling Anatomy*

Summary. The root and shoot growth of oat (Avena sativa L.) and green foxtail (Setaria viridis (L.) Beauv.) were generally reduced proportionately to the concentration of chlorthal dimethyl applied. Foxtail shoot growth was stimulated by a concentration of 2 ppm. Cells in the shoot and root meristems of treated plants were completely disarranged and considerably hypertrophied. Differentiation was irregular and extended nearer the apices in tissue of treated seedlings than in normal tissue. Histochemical tests showed that the amount of starch, proteins and nucleic acids in seedling tissue decreased with an increase of chlorthal dimethyl concentration, whereas the endosperm of the seeds retained more starch and protein than the controls. The walls of shoot nieristem and root epidermal cells were thickened or altered so as to stain more intensely than corresponding cells in untreated tissue. Effet du diméthyle chlorthal sur l'anatomie des plantules d'avoine et de séaire