Effect of selenium on uptake and assimilation of some plant nutrients

Selenium is an essential element for humans, animals and some species of microorganisms. However, in higher plants the role of selenium is still unclear. Because selenium enrichment may influence the nutrient balance of plants. Therfore a first experiment was done to test the effects of selenite-Se (Na2SeO3.5H2O) on germination of wheat plants and on some nutrient elements content under salinity. Wheat plants (Gmeza 9)grown in sand culture, were soaked to the following concentrations of sodium selenite (0, 2.5, 5, 10, and 20µM.dm-3)for 24 hours. Selenite concentration enhanced the growth and germination percentage. After growth, the wheat plants were exposed to different concentrations (0, 2, 4, 6,8 and 10 dS.m-l) of the mixture NaCI+CaCI2 (2: 1 ratio). However. the results were not significantly but selenium uptake by wheat plants reduced content of some elements (Na, K, Mg , N )and Protein. Selenite increased the content of Ca ions but the salinity reduced content of Ca, N and protein, while it increased the content of Na, K and Mg. The effect of selenite and salinity together reduced uptake of Na, K, Mg, N and protein but increased the uptake of Ca in shoot wheat plant. The second experiment was conducted in the greenhouse of the Faculty of Agriculture. It was prepared the wheat grains (Gemayzeh 9) which is unhesitant to salinity as well as seeds of beans (Sakha 3), with some additional selenium concentrations applied with different 3 methods before and after cultivation (soaking, foliar and soaking + foliar), in combination with additional salts added in irrigation water. It was noticed, generally that faba bean plants and their, nutrient uptake were high by adding selenium as soaking and soaking +foliar ,while the nutrient contents in shoot were high by adding selenium as soaking and foliar .However the nutrient content in roots were high by adding selenium as soaking, foliar and soaking +foliar. Also it was noticed that in wheat plant, nutrients uptake were increased by adding selenium as soaking or soaking +foliar,as well as nutrient content in shoot were increased by adding selenium as soaking, foliar or soaking + foliar, but in root the results wasnt the same different result depend on each nutrient. For the carbohydrate also it was noticed the best result obtained was when adding selenium by soaking. The average values show in wheat plant by soaking that forming of carbohydrate (without adding Se)were increased at begging then it decreased at the end. The average values show in wheat plant by foliar that forming of carbohydrate (without adding Se) small increased but when adding the first concentration from selenium it followed by high increase in carbohydrate forming as salinity increase comparing with control result, but when adding the second concentration the carbohydrate increased at begging then it decreased at the end.