Genetic hotspots for grain zinc, grain iron, and kernel weight in bread wheat under disease‐free and spot blotch environments

This study aimed to identify candidate genes controlling grain zinc content (GZnC), grain iron content (GFeC), and 1000‐kernel weight (TKW) under disease‐free (DF) and spot blotch (SB) conditions in bread wheat ( Triticum aestivum ), and to assess the impact of SB on these traits. A panel of 1500 elite wheat genotypes was evaluated across six environments, encompassing both DF and SB conditions. The results provided preliminary evidence that SB influences micronutrient accumulation, leading to an increase in GFeC and a reduction in GZnC. Multi‐environment genome‐wide association study identified genomic hotspots associated with GFeC and GZnC on chromosomes 7A, 7B, and 1A under DF conditions, and on chromosomes 5B, 7B, 6A, and 4D under SB conditions. Significant loci associated with TKW were identified on chromosomes 4A and 7A under DF condition, and on chromosomes 3B, 7A, and 7D under SB condition. Notably, two marker‐trait association (MTAs), 2A_32029594 and 4D_43879057, exhibited stable associations with GZnC and GFeC across environments. Expression analysis further revealed that the gene TraesCS2A02G072500 , associated with MTA 2A_32029594, is upregulated under zinc limited conditions, suggesting its potential role in zinc homeostasis.