Genetic characterization and deployment of a major gene for grain yield on chromosome arm 1BS in winter wheat

Winter bread wheat ( Triticum aestivum L., 2 n = 6 × =42, AABBDD) cultivars “Duster” and “Billings” have occupied significant acreages in the Southern Great Plains for their outstanding yielding ability. In this study, we discovered a major quantitative trait locus (QTL) QYld.osu-1BS for grain yield in a population of 260 doubled haploid (DH) lines derived from the cross of Duster and Billings. When the population was tested under field conditions for 2 years, QYld.osu-1BS explained 13.9% and 23.5% of the total phenotypic variation. However, no crossover was observed among 40 genotyping-by-sequencing markers covering the region from the telomere to 25.3 Mb in the population of 260 DH lines. Furthermore, no crossover was observed in the region from the telomere to 18.4 Mb, when up to 4146 individual plants within F 2:4 lines derived from the cross of Duster and Billings were screened. The 1BL-1RS translocation was not observed in the region with the abnormal recombination rate in Duster or Billings. Duster is a unique haplotype in the whole exome capture dataset, compared with 57 cultivars and breeding lines with various genetic backgrounds. Unique sequences of the QYld.osu-1BS allele for the higher grain yield in Duster were identified, and kompetitive allele specific PCR (KASP) markers for the unique sequences were developed for breeding of novel cultivars with increased grain yield in winter wheat.