Identification of Potential Genomic Regions and Candidate Genes for Spring Wheat Pre‐Harvest Sprouting Resistance Using Multiple Genome‐Wide Association Study Models

ABSTRACT

Pre‐harvest sprouting is a critical constraint limiting stable spring wheat production worldwide. Mining reliable quantitative trait loci (QTLs) for pre‐harvest sprouting resistance and functional genes governing pre‐harvest sprouting resistance is essential to accelerate targeted molecular breeding for spring wheat improvement. In this study, the pre‐harvest sprouting‐related traits of 210 spring wheat varieties (originating from China and Central Asia) were systematically evaluated in four environments, and a large‐scale genome‐wide association study (GWAS) was performed using the 100 K SNP array with four models. As a result, 201 quantitative trait loci (QTLs) were identified to be associated with pre‐harvest sprouting‐related traits in four environments, of which 122 core QTLs were identified at least two times. Poaceae species retain conserved seed dormancy pathways, enabling rice functional genes to assist wheat candidate gene screening. Therefore, genes regulating seed germination and pre‐harvest sprouting in rice were collected, and 75 key candidate genes were ultimately mined within QTL intervals via homology and functional profiling. These high confidence candidate genes modulate pre‐harvest sprouting resistance through ABA/GA biosynthesis and signal transduction, energy metabolism and redox homeostasis. Overall, based on GWAS and homology analysis, we discovered multiple QTLs and important candidate genes that affect pre‐harvest sprouting resistance in spring wheat and verified the reliability of this strategy. These candidate genes and markers will help to elucidate the internal mechanism of pre‐harvest sprouting resistance in spring wheat and facilitate molecular breeding.