Difference in Selenium Accumulation in Shoots of Two Rice Cultivars1

ABSTRACTTwo japonica rice (Oryza sativa L.) cultivars, Xiushui 48 and S. Andrea, differing in their ability to accumulate Se in the grain (as high as a three-fold difference), were compared for selenium (Se) accumulation in their shoots when their growth media was supplied with different forms of Se. Results indicated that when treated with 0.25 μmol L−1 Na2SeO3, Xiushui 48 accumulation of Se in the shoots was significantly more rapid (P ≤ 0.05) than S. Andrea, probably because of greater Se uptake and transport in Xiushui 48. Xiushui 48 rice seedlings had a higher shoot-Se accumulation rate and absorbed selenocysteine (Se-Cys) more rapidly than S. Andrea seedlings. However, when treated with Se as 0.25 μmol L−1 selenomethionine (Se-Met), the S. Andrea seedlings' accumulation rate was significantly greater (P ≤ 0.05) than that of Xiushui 48. Possibly, the high Se accumulation rate of Xiushui 48 seedling shoots compared to S. Andrea shoots was the result of a higher capacity of Xiushui 48 to transform selenite to organic Se compounds and a higher selenite uptake rate.