Abstract:Awn is a needle-like structure located on the ear of plants. It is widely found in the grass family such as rice, wheat, sorghum and barley, and the structure of awn varies in different crops. In wheat, awn plays an important role in improving the photosynthetic efficiency and yield, and in preventing damages caused by pest birds, insects and adverse conditions. Genes related to the development of wheat awn have already been mapped and genetically analyzed, but only one of the four major awn-inhibiting genes, B1( Tipped1), has been cloned. In this study, conducted on a BC3F6 genetic population( YN3/YZ1) and a natural population, we estimated the relationship between the awn and agronomic traits, and found that awn had significant effects on plant height and yield. Genome-wide association studies( GWAS) based on wheat 660K SNP array identified genomic regions on chromosomes 5AL and 6BL significantly related to awn trait, which corresponded to awn-inhibiting genes B1 and B2 respectively. From transcriptome data of long-awned and tip-awned near-isogenic lines( NILs), 23 differentially expressed genes were identified from the 6BL candidate interval. These results will facilitate the B2 gene cloning in the future.