Large-scale identification and association analysis of wheat grain weight genes using rice orthologs.

Abstract

Key message: The study identifies 314 wheat orthologs of rice grain weight-related genes, with multi-environment association analysis of 490 accessions uncovering 146 genes significantly linked to grain weight, offering potential targets for yield improvement. Grain weight is a key determinant of wheat yield. Dissection of more grain weight-related genes is crucial for improvement of wheat yield. Using homologous cloning method, a total of 104 rice grain weight-related genes was collected from published studies and their corresponding 314 orthologs were identified in wheat. Spatiotemporal expression analysis reveals that grain weight genes exhibit diverse expression profiles, with few showing grain-specific expression patterns. Approximately 36,000 variants in these grain weight-related genes were identified in a large natural wheat population. Candidate gene association analysis, using 490 common wheat accessions across five environments, reveals that 146 genes of them are significantly associated with grain weight. As a result of breeding practices, favorable alleles were significantly accumulated in modern wheat cultivars. These findings contribute to a better understanding of the genetic architecture of grain development and weight, offering potential targets for future wheat yield improvement.