RE-TRANSLOCATION OF SELENIUM DURING GENERATIVE GROWTH IN WHEAT

The effect of nitrogen (N) and sulfur (S) availability on the re-translocation of selenium (Se) in spring wheat (Triticum aestivum) in a greenhouse experiment using ⁷⁵Se labeled selenate was performed. Spring wheat was grown hydroponically and pulsed with ⁷⁵selenate at growth stage Z1.4, Z 4.0, and grown in nutrient solutions having N/S ratios of 4, 7, 15, 25 and 35. Plants were separated into leaves, stem, ear and grains prior to ⁷⁵Se Becquerel activity (Bq) measurements. The wheat plant ⁷⁵Se activity varied from 72 to 702 Bq. Selenium and N application at heading maximized the plant Se re-translocation from leaf and stem to grains. High levels of N enhanced the re-translocation of ⁷⁵Se while S inhibited this process. The S supply to the wheat plant should not be deficient due to decreased yield and thereby reduced total Se re-translocation, but the Se concentration of the single grains may be high.