Identification of Genomic Loci Controlling Grain Macro and Micronutrient Variation in a Wild Barley (Hordeum vulgare spp. spontaneum) Diversity Panel

Nutrient deficiencies in humans are problematic on a global scale but are more prevalent in regions where high-quality and nutrient-dense foods are scarce. Developing nutrient-rich crops that thrive in these regions of the world would help alleviate the disparity. We leveraged the wild barley (Hordeum vulgare spp. spontaneum) Diversity Collection (WBDC) (N = 232) to characterize the variation in seed macronutrient (P, K, Ca, and Mg) and micronutrient (B, Cu, Fe, Mn, and Zn) contents found in this subspecies and to reveal chromosomal regions associated with these traits. Most micro- and macronutrients displayed variation in the WBDC and, except for boron and phosphorous, had a modest level of heritability (>0.5). Variation due to environment was significant (p < 0.001) for each element, except iron, and genotype was significant for all the tested nutrients, except boron. Thirty-seven marker–trait associations (MTAs) were detected for three (K, Ca, and Mg) of the four macro- and four (Cu, Fe, Mn, and Zn) of the five micronutrients. Several compelling candidate genes harbored within MTAs were also identified, including ABC transporters, NAC transcription factors, and bZIP transcription factors.