Abstract：
Wheat powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), is one of the most devastating diseases affecting wheat throughout the world. Breeding and growing resistant wheat cultivars is one of the most economic and effective methods to control the disease, and as such, identifying and mapping the new and effective resistance genes is critical. Baidatou, a Chinese wheat landrace, shows excellent field resistance to powdery mildew. To identify the resistance gene(s) in Baidatou, 170 F7:8 recombinant inbred lines (RILs) derived from the cross Mingxian 169/Baidatou were evaluated for powdery mildew response at the adult-plant stage in the experimental fields in Yangling (YL) of Shaanxi Province and Tianshui (TS) in Gansu Province in 2019, 2020, and 2021. The relative area under disease progress curve (rAUDPC) of Mingxian 169/Baidatou F7:8 RILs indicated that the resistance of Baidatou to powdery mildew was controlled by quantitative trait loci (QTLs). Based on bulk segregation analysis combined with the 660K single nucleotide polymorphism (SNP) array and genotyping by target sequencing (16K SNP) of the entire RIL population, two QTLs, QPmbdt.nwafu-2AS and QPmbdt.nwafu-3AS, were identified, and these accounted for up to 44.5% of the phenotypic variation. One of the QTLs was located on the 3.32 cM genetic interval on wheat chromosome 2AS between the kompetitive allele-specific PCR markers AX-111012288 and AX_174233809, and another was located on the 9.6 cM genetic interval on chromosome 3AS between the SNP markers 3A_684044820 and 3A_686681822. These markers could be useful for successful breeding of powdery mildew resistance in wheat.
摘要：
小麦白粉病，由生物营养真菌Blumeriagraminisf.sp.小麦（Bgt），是影响全世界小麦的最具破坏性的疾病之一。选育抗病小麦品种是防治该病最经济有效的方法之一,因此，识别和定位新的和有效的抗性基因是至关重要的。Baidatou,一种中国小麦地方品种，表现出优异的抗白粉病性。为了鉴定白大头的抗性基因，分别于2019年、2020年和2021年在陕西杨凌（YL）和甘肃天水（TS）试验田中对来自明县169/白达头杂交的170个F7：8个重组自交系（RILs）进行成株期白粉病响应评价。明县169/白大头F7：8RIL的疾病进展曲线下相对面积（rAUDPC）表明，白大头对白粉病的抗性受数量性状位点（QTLs）控制。基于批量分离分析，结合660K单核苷酸多态性（SNP）阵列和通过整个RIL群体的靶测序（16KSNP）进行基因分型，两个QTL，QPmbdt。nwafu-2AS和QPmbdt。nwafu-3AS，被确认,这些占表型变异的44.5%。其中一个QTL位于竞争性等位基因特异性PCR标记AX-111012288和AX_174233809之间的小麦2AS染色体上的3.32cM遗传区间上，另一个位于SNP标记3A_684044820和3A_686681822之间的3AS染色体上的9.6cM遗传区间上。这些标记可用于小麦白粉病抗性的成功育种。
