Effects of Sodium Selenite Application on Photosynthesis and Antioxidant Enzyme Activity of Tartary Buckwheat

Abstract

【Objective】 Selenium is a vital nutrient but deficient in many soils. Sodium selenium can be used as a selenium fertilizer. This paper investigates the impact of its application on photosynthesis and activity of antioxidant enzymes of Tartary buckwheat. 【Method】 The experiment was conducted in pots using the variety Xiyang as the model plant. There were 5 treatments by mixing the sodium selenite with soil at a ratio (weight /weight) ranging from 0 (control) to 40 mg/kg. In each treatment, we measured the height, fresh and dried weight, photosynthetic parameters, and antioxidant enzyme activities of the crop. 【Result】 ①Applying sodium selenite can significantly increase biomass and height of the crop, compared to the control, but only when application ratio did not exceed 10 mg/kg. ② Compared to the control, applying sodium selenite increased net photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll by 7.57%, 32.70%, 28.12% and 6.96% respectively, while reduced the intercellular CO2 concentration by 13.95%. It was found that applying 5 mg/kg of sodium selenite increased CO2 assimilation capacity. The effect of sodium selenite in improving the photosynthesis was most effective during the full flowering stage. ③Compared to the control, applying 5 mg/kg of sodium selenite increased activity of catalase by 3.29%; however, increasing the application to 10 mg/kg enhanced the activity of superoxide dismutase and peroxidase by 261.74% and 88.63%, respectively. ④The growth and development of Tartary buckwheat were inhibited when the concentrations of disodium selenite were 20 mg/kg and 40 mg/kg. 【Conclusion】 Our results show that applying sodium selenite to soil can improve photosynthesis and antioxidant enzyme activities of Tartary buckwheat, especially at the flowering stage, but only when the application ratio did not exceed 10 mg/kg.

Keywords

• tartary buckwheat
• sodium selenite
• photosynthetic characteristics
• antioxidant enzyme activity