QUALITY OF THE RYEGRASS AND LETTUCE YIELDS AS AFFECTED BY SELENIUM FERTILIZATION

The effect of Se-fertilization on the chemical composition and anti-ox idative properties of ryegrass and lettuce was studied in a pot experi ment. The addition of Se enhanced its relative incorporation in solubl e and insoluble proteins and diminished it in free amino acids. It als o affected the anti-oxidative systems of the plants. The glutathione p eroxidase (GSH-Px) activity found in both plant species increased with increasing Se-fertilization, whereas the superoxide dismutase (SOD) a ctivity as well as the concentration of vitamin E decreased. This may indicate that the synthesis of SOD and vitamin E was reduced because t he requirement of these anti-oxidants was diminished by antioxidative function of Se.