Linkage and association analysis to identify wheat pre-harvest sprouting resistance genetic regions and develop KASP markers

Pre-harvest sprouting (PHS) of wheat (Triticum aestivum L.) is one of the complex traits that result in rainfall-dependent reductions in grain production and quality worldwide. Breeding new varieties and germplasm with PHS resistance is of great importance to reduce this problem. However, research on markers and genes related to PHS resistance is limited, especially in marker-assisted selection (MAS) wheat breeding. To this end, we studied PHS resistance in recombinant inbred line (RIL) population and in 171 wheat germplasm accessions in different environments and genotyped using the wheat Infinium 50 K/660 K SNP array. Quantitative trait loci (QTL) mapping and genome-wide association studies (GWAS) identified 59 loci controlling PHS. Upon comparison with previously reported QTL affecting PHS, 16 were found to be new QTL, and the remaining 43 loci were co-localized with QTL from previous studies. We also pinpointed 12 candidate genes within these QTL intervals that share functional similarities with genes previously known to influence PHS resistance. In addition, we developed and validated two kompetitive allele-specific PCR (KASP) markers within the chromosome 7B region identified by linkage analysis. These QTL, candidate genes, and the KASP marker identified in this study have the potential to improve PHS resistance of wheat, and they may enhance our understanding of the genetic basis of PHS resistance, thus being useful for MAS breeding.