Bulked QTL-Seq identified a major QTL for the awnless trait in spring wheat cultivars in Qinghai, China

The awnless trait is the favorite trait for wheat breeding in Qinghai, China, but the major gene underlying the trait is unknown. This study aimed to analyze a recombinant inbred line (RIL) population containing 112 lines by crossing common wheat varieties GY448 (awnless) and GY115 (awned) using genotyping-by-sequencing analysis. A total of 56.62 Gb of clean sequence data were generated. A major gene was identified for the awnless trait based on 101,275 single-nucleotide polymorphisms by quantitative trait locus (QTL)-seq analysis. The region from 685.50 to 709.77 Mb on chromosome 5AL contained 334 genes and 394 transcripts, including <i>B1</i>, the major gene controlling the awnless trait. A 25-bp indel located in the B1 promoter region has a diagnostic value for the awnless/awned genotypes in the RIL population. A total of 42 spring wheat cultivars in Qinghai, China, were analyzed. Further, 23 awnless cultivars had the alleles of the GY448 parent, while 19 awned cultivars had the alleles of the GY115 parent. <i>B1</i> is crucial in the awnless trait in wheat cultivars in Qinghai, China. The findings of this study might guide the breeding of new wheat cultivars in this region.