EFECTOS DEL PARAQUAT SOBRE EL CRECIMIENTO Y LA MORFOLOGÍA DE LA MICROALGA Dunaliella tertiolecta.

Abstract

Different doses of the metilviologen herbicide paraquat were applied on the microalgae Dunaliella tertiolecta under non controlled conditions to determine the effects on the growth and the morphology. We found out that, the best way to evaluate the growth in this case is the cellular density. Doses lower than 0.008 ppm had an increasing tendency in cellular density while greater doses up to 0.04 ppm had a declining tendency. The morphology and the movement of the microalgae are profusely disturbed at high concentrations. Finally they die abruptly (non programmed death). At low concentrations, the detoxificant SOD and carotene system seem to function well. A lethal dose of 0.006 ppm was found for this case.