The effect of selenite and selenate on selected physiological and biochemical parameters in three aquatic plants

The aim of our research was to study the effect of selenite (5 mg/L) and selenate (5 mg/L) on selected physiological and biochemical parameters in three aquatic plants (Ceratophyllum demersum, Myriophyllum spicatum and Potamogeton perfoliatus). Plants were cultivated outdoors in nine containers and six weeks treated with sodium selenit (Na2SO3) and sodium selenat (Na2SO4). Weekly we measured the potential photochemical efficiency of photosystem II, electron transport system (ETS) activity and the content of pigments (chlorophyll a, chlorophyll b, carotenoids and anthocyanins) in the controled and treated plants. All three studied species, treated with selenate, had a lower potencial photochemical efficiency of PS II than the control plants and plants, treated with selenite. In other parameters we did not observe the clear difference between the effect of selenite and selenate on the studied macrophytes. Treated plants of Ceratophyllum demersum had higer ETS activity than the control plants, while in Myriophyllum spicatum ETS acivity of treated plants was lower as in the control plants. The amount of pigments was the lowest in treated plants of Potamogeton perfoliatus in comparison with Ceratophyllum demersum and Myriophyllum spicatum. We found out that Potamogeton perfoliatus was least tolerant to selenite and selenate in concentration 5 mg/L. The most tolerant was Ceratophyllum demersum and therefore the most suitable for the removal of selenium from water