Unveiling Novel Genetic Loci and Superior Alleles for Nickel Accumulation in Wheat via Genome-Wide Association Study

Nickel (Ni) pollution poses significant threats to human health and crop development through the food chain. This study aimed to identify the novel genomic regions and superior alleles associated with Ni accumulation in wheat (<i>Triticum aestivum</i> L.) grains using genome-wide association analysis (GWAS) with a diversity panel of 207 bread wheat varieties. In total, five unique genetic loci associated with Ni accumulation were identified and they explained, on average, 8.20-11.29% of the phenotypic variation. Among them, three unique genetic loci were mutually verified by different statistical models in at least two environments, indicating their stability across different environments. Moreover, the highest effect quantitative trait nucleotide (QTN) AX-111126872 with a quantitative trait locus (QTL) hotspot on chromosome 6B identified in this study was not reported previously. Three putative candidate genes linked to Ni accumulation were revealed from the stable genetic loci. Among them, one gene associated with the stable genetic locus on chromosome 6B (AX-111126872) encodes the <i>glycine-rich proteins</i> (<i>GRPs</i>) as a critical factor influencing Ni accumulation in wheat grains. This study increases our understanding of the genetic architecture of Ni accumulation in wheat grains, which is potentially helpful for breeding wheat varieties without Ni toxicity.