Genotypic variation in micronutrient and cadmium concentrations in grains of 35 upland rice cultivars

摘要

Rice is the primary food for half of the world population and in Brazil it is the most consumed cereal. Plant breeders have selected rice cultivars for high micronutrient density traits, but there is a need to include other elements that can affect micronutrient bioavailability, such as cadmium (Cd). The study was conducted with the purpose of evaluating the relationships among Cd, zinc (Zn), iron (Fe), and selenium (Se) concentrations in grains of upland rice cultivars. Thirty-five upland rice cultivars were grown to maturity in a pot soil experiment under greenhouse conditions. Cadmium and micronutrient concentrations in grains ranged widely, but showed a close relation with grain yield. While the grain-Cd concentration increased with the increaseof grain yield, an opposite relationship was found for grain micronutrient concentrations, which declined with increased grain yield. It appears that rice plants use different mechanisms to regulate the accumulation of toxic and essential heavy metals into grains.