Influence of Selenium on Growth, Antioxidants Production and Physiological Parameters of Rice ( Oryza sativa L.) Seedlings and Its Possible Reversal by Coapplication of Sulphate

Abstract

The effect of selenate (Na2SeO4) and sulphate (Na2SO4) was studied on growth and metabolism in two rice cultivars cv. satabdi and cv. khitish. Selenate at low concentration (2 μM) expressed growth promoting effect on rice seedlings as opposed to its high concentration (≥20 μM) where the test seedlings showed stunted growth with browning at the apices of both roots and shoots. The chlorophyll contents showed a dose dependent effect. Both chlorophyll a and chlorophyll b contents were inhibited with increase in selenate concentrations. The effect was more pronounced in cv. satabdi compared to cv. khitish.The level of accessory pigments was deferentially affected by selenium treatment. Simultaneously, the fluorescence intensity and Hill activity decreased with increase in selenate concentrations in the test seedlings. It is assumed that selenium plays a protective role in plants subjected to stress and prevents the formation of reactive ...