| Summary: | A recessive gene <i>PmQ</i> conferring powdery mildew resistance was previously localized on the long arm of chromosome 2B in winter wheat landrace Qingxinmai. Breeder-friendly molecular markers are necessary for introgressing this gene into adapted wheat backgrounds for developing disease-resistant wheat cultivars. Three Kompetitive allele-specific PCR (KASP) markers were developed and validated based on SNP variants detected by Bulked segregant analysis-RNA-Seq (BSR-Seq) analysis using a recombinant inbred population derived from cross Qingxinmai × 041133. Two polymorphic SSR markers were also developed from the motifs in the Chinese Spring reference genome sequences of the target genomic region. Those markers were incorporated into a more saturated genetic linkage map for <i>PmQ</i>. The two flanking markers, <i>Xicsq405</i> and <i>Xicsk18</i>, are 1.1 and 0.9 cM from <i>PmQ</i>, respectively. The KASP marker <i>Xicsk19</i> produced unique amplification pattern in 158 out of 160 wheat cultivars or breeding lines. This marker with the gene-linked SSR markers <i>Xicsqc</i>, <i>Xicsqd</i> and <i>Xicsq405</i> provides an efficient means in molecular marker-assisted selection for <i>PmQ</i> in wheat breeding. The corresponding genomic region of <i>PmQ</i> in the Chinese Spring reference genome has a conserved synteny with the genomes of sequenced wheat cultivars and <i>Triticum durum</i>, <i>T. diccocoides</i>, <i>T. uratu</i>, and barley. The annotation of the two genes, <i>TraesCS2B01G517400.1</i> and <i>TraesCS2B01G517700.1</i>, associated with plant defense against pathogens placed a start for cloning <i>PmQ</i>.
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