GENOTYPIC DIFFERENCES IN CONCENTRATIONS OF IRON, MANGANESE, COPPER, AND ZINC IN POLISHED RICE GRAINS

Identification of genotypic differences in micronutrient concentration s of staple food crops is essential if plant breeding strategies are t o improve human mineral nutrition. The concentrations of zinc (Zn), ir on (Fe), copper (Cu), and manganese (Mn) in polished grains of 285 ric e (Oryza saliva L.) genotypes and the relationship between concentrati ons of the four micronutrient elements and concentrations of protein a nd lysine were examined. Significant differences (P<0.01) were found i n the concentrations of Zn, Fe, Cu, and Mn in polished rice with a fai rly normal distribution among rice genotypes. On average, Cu and Zn co ncentrations of Indica rice were about 2-fold higher than Japonica ric e, while Fe concentrations of Japonica rice were slightly higher than Indica rice. Among Indica rice genotypes, red rice contained higher Zn than white rice. Protein and lysine concentrations differed considera bly among the genotypes, but no close relationship between the micronu trients and protein or lysine concentrations was observed among genoty pes. Sixteen genotypes with significantly higher grain Zn, Fe, Cu, and Mn concentrations were identified.