Induced Mutagenesis Improves Grain Protein and Micronutrient (Fe and Zn) Content in Spring Wheat (Triticum aestivum L.)

Improving grain nutritional quality without reducing yield remains a major challenge in wheat breeding. This study aimed to identify advanced mutant lines of spring wheat with enhanced grain protein, iron (Fe), and zinc (Zn) contents combined with reduced phytate levels to improve mineral bioavailability. Mutant lines were developed from the spring wheat cultivar Zhenis using gamma irradiation (100 and 200 Gry) and evaluated for yield-related traits, grain morphometry, and nutritional parameters. Significant phenotypic and genetic variation was observed among the M5 mutant lines. Grain protein content ranged from 13.23% to 15.63%, and 46.7% of the lines showed significantly higher protein levels than the parent cultivar. Likewise, 43.3% of the mutant lines showed increases in grain iron and zinc contents of up to 3.4- and 2.94-fold, respectively, compared to the control. Phytate-to-mineral molar ratios were significantly reduced, indicating improved mineral bioavailability. Correlation analysis revealed positive associations between micronutrient accumulation and grain morphometric traits, particularly grain area. No strong negative relationship between nutritional quality and yield-related traits was detected in the selected lines. These results demonstrate that gamma-induced mutagenesis is an effective approach for developing biofortified wheat genotypes with improved nutritional quality and stable agronomic performance.