The accumulation of arsenic (As) in rice grain is a potential threat to human health. Our study investigated the possible mediatory role of selenite fertilization on As uptake and accumulation by rice (Oryza sativa L.) under different water management regimes (aerobic or flooded) in a pot experiment. Soil solutions were also extracted during the growing season to monitor As dynamics. Results showed that As contents in the soil solutions, seedlings, and mature rice were higher under flooded than under aerobic water management. Under aerobic conditions, selenite additions slightly increased As concentrations in soil solutions (in the last two samplings), but decreased As levels in rice plants. Relative to the control, 0.5 mg kg⁻¹ selenite decreased rice grain As by 27.5%. Under flooded conditions, however, selenite additions decreased As in soil solutions, while increased As in rice grain. Tendencies also showed that selenite additions decreased the proportion of As in rice shoots both at the seedling stage and maturity, and were more effective in aerobic soil. Our results demonstrate that the effect of selenite fertilizer on As accumulation by rice is related to water management.

稻米中砷（As）的积累是对人类健康的潜在威胁。我们的研究在盆栽试验中研究了在不同水分管理方式（有氧或淹水）下，亚硒酸盐施肥对水稻（水稻）吸收和积累砷的可能介导作用。在生长季节也提取土壤溶液以监测砷的动态。结果表明，淹水后土壤溶液，幼苗和成熟水稻中的砷含量高于需氧水管理下的砷含量。在有氧条件下，亚硒酸盐的添加使土壤溶液中的As浓度略有增加（在最近两次采样中），但水稻植株中的As含量却降低了。相对于对照，0.5 mg kg ^-1亚硒酸盐使稻米中As含量降低了27.5％。然而，在水淹条件下，亚硒酸盐的添加降低了土壤溶液中的砷，而增加了稻米中的砷。趋势还表明，亚硒酸盐的添加在苗期和成熟期都降低了芽中砷的比例，并且在需氧土壤中更有效。我们的结果表明，亚硒化肥对水稻砷积累的影响与水分管理有关。