Iron and zinc partitioning in rice grain

Abstract

One-third of the world population has Fe and Zn deficiency. Increasing Fe and Zn concentrations in rice grain is suggested as a sustainable solution to the problem. The partitioning of Fe and Zn in rice grain has to be clearly understood. The objectives of this study were to indicate the relationship between Fe and Zn concentrations in white rice, and the partitioning of these 2 elements among different grain parts of different rice genotypes. Four upland and 11 lowland rice genotypes were grown under wetland condition until maturity. Paddy grain was collected and dehusked manually by hand before being partitioned into white rice, embryo and aleurone; and evaluated for Fe and Zn concentrations. The parti-tioning of Fe in white rice ranged from 29% to 56%, while it was from 60% to 80% for Zn. There was a positive correlation between Fe concentration and Fe partitioning in the white rice (r = 0.75***), but Fe concentration in white rice negatively correlated with Fe partitioning in the aleurone (r = -0.64***). In the case of Zn, Zn concentration in white rice positively correlated with Zn partitioning in the white rice (r = 0.76***), but negatively correlated with Zn partitioning in the embryo (r = -0.72***). This study indicated that increasing Fe and Zn concentrations in white rice can be accomplished by increasing Fe and Zn partitioning in the white rice; and decreasing partitioning in the aleurone and the embryo for Fe and Zn, respectively.