Growth Regulator-Like Activity of Atrazine and Ametryne

Abstract

Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] and 2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine (ametryne) were tested for growth regulatorlike effects. In the presence of 10 μg/ml of kinetin, atrazine had no effect on the growth of callus tissue of soybean (Glycine max Merr. ‘Lee’), but ametryne at 10−14M concentration stimulated callus growth and the production of roots. High concentrations of both atrazine and ametryne inhibited the growth of excised roots of tomato (Lycopersicon esculentum Miller ‘Atkinson’). Ametryne, and to a lesser extent atrazine, increased percent germination of seed of lettuce (Lactuca sativa L. ‘Grand Rapids’) and tobacco (Nicotiana tobaccum L. ‘Sansum’) exposed to only 4 min of red light. Both atrazine and ametryne stimulated adventitious root formation by excised hypocotyls of mung beans (Phaseolus aureus Roxb.) in the absence of 10 ppm of exogenous indoleacetic acid (IAA) but not in its presence. A high concentration of atrazine (10−6M) in the presence of IAA decreased root initiation in comparison with the IAA-treated controls.