Détection Rapide de Divers Herbicides dans l'Eau par la Mesure in vivo de l' Activité de Ia Nitrate Reductase de Lemna minor L.

Abstract

Lemna plants were laid on nutrient solutions containing different herbicides at concentrations of 0.05; 0.1; 0.5 and 1 mg/1. The nitrate reductase activity was measured after 20 hrs, fresh weight and chlorophyll content were determined after 5 days. The nitrate reductase activity was inhibited in Lemna in contact with the following groups of herbicides: triazines, ureas, diazines, bipyridyliums, phenols and benzonitriles, but not with dinitroanilines and amides, except propanil. A concentration of 1 mg/1 resulted in the same inhibition of growth and nitrate reductase activity. At 0.5 and 0.1 mg/1, the correlation remained valid, chiefly for triazine, urea and diazine herbicides, but also for propanil, dinoterb and diquat. At 0.05 mg/1, the inhibition of nitrate reductase activity is too low to give significant results.