Energy-Dispersive X-ray Fluorescence Spectrometry for Cost-Effective and Rapid Screening of Pearl Millet Germplasm and Breeding Lines for Grain Iron and Zinc Density

Comparison of energy-dispersive X-ray fluorescence (XRF) and inductivelycoupled plasma-optical emission spectroscopy (ICP) for iron (Fe) and zinc(Zn) densities in pearl millet grain samples from 11 trials showed significantdifferences between these two methods for both micronutrients. XRF valueswere more often higher than the ICP values for both micronutrients, but thedifferences were significant in only 15?38% genotypes for Fe and in 7?25%genotypes for Zn across the trials. In 82% genotypes the differencesbetween these two methods were ?6 mg kg?1 for Fe; and in 88% genotypes,the differences were ?4 mg kg?1for Zn. There were highly significantand high positive correlations between ICP and XRF for both micronutrients.Selection of genotypes above the XRF trial mean for Fe/Zn included atleast 30% top-ranking genotypes based on ICP. Therefore, XRF can be usedfor cost-effective and rapid screening of a large number of grain samples inpearl millet biofortification programs