Wheat grain quality changes with water stress, zinc, and iron applications predicted by the solvent retention capacity (SRC)

Due to a lack of assessment tools for large samples, the effects of foliar Zn and Fe applications on grain nutritional and quality traits for wheat genotypes from diverse species and poloidal levels under water-limited conditions are less addressed. With the availability of simple/rapid solvent retention capacity (SRC) tests to assess a large number of samples for grain quality attributes, thirty-five wheat genotypes from 18 different species were field evaluated under four treatments of control, zinc (Zn), iron (Fe), and Zn + Fe foliar applications in two moisture regimes. Grain yield (GY) and thousand kernel weight (TKW) decreased due to water stress, while the grain quality traits including SRC values, flour protein content (FPC), Zn, and Fe content increased. Although diploid species showed higher FPC, grain Zn, and Fe than tetraploid (4x) and hexaploid (6x) species across all treatments, they presented much lower SRC values attributed to protein quality. Zinc application increased SRC profiles for 4x and 6x wheat and alleviated GY and TKW reduction due to water stress. A significant correlation between various grain and flour parameters confirmed the validity of the results and SRC quality predictions.