Wheat, a major food crop, faces significant yield constraints due to losses caused by various diseases, especially rusts and powdery mildew. Since the causal organisms are always evolving, there is a never-ending hunt for new genes/quantitative trait loci (QTLs) for resistance to control the damage. For this purpose, Triticum durum–Aegilops speltoides backcross introgression lines (DS-BILs) developed in our wide hybridization programme were screened against stripe rust and powdery mildew at both seedling and adult plant stages. DS-BILs showed complete to moderate resistance at the adult plant stage while varying resistance and susceptibility at the seedling stage. A total of 1095 single-nucleotide polymorphisms (SNPs) identified on 14 chromosomes of T. durum, using genotyping by sequencing, were used for QTL mapping. Eleven unique QTLs, across six chromosomes (chr1B, chr2A, chr2B, chr3B, chr6B and chr7B) were identified for resistance, four QTLs for field mixture of stripe rust pathotypes, two QTLs for stripe rust pathotype 78S84 and five QTLs for field mixture of powdery mildew pathotypes using stepwise regression-based likelihood ratio test for additive effect of markers and single-marker analysis. Eleven DS-BILs carrying multiple QTLs were identified which will serve as a useful resource to transfer the respective resistance to susceptible cultivars to develop all stage resistant elite cultivars where QTL for stripe rust resistance QYrAs.pau-2A.1 (LOD 3.8, PVE 24.51 linked to SNP S2A_16016633) and QTL for powdery mildew resistance QPmAs.pau-6B (logarithm of the odds (LOD) 3.2, phenotypic variation explained (PVE) 17.75 linked to SNP S6B_26793381) are major targets of the transfer.

中文翻译：

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硬粒小麦-Aegilops speltoides 回交渐渗系条锈病和白粉病抗性的QTL定位

小麦作为主要粮食作物，由于各种病害，特别是锈病和白粉病造成的损失，面临着严重的产量限制。由于致病生物总是在进化，因此对新基因/数量性状基因座 (QTL) 的寻找是永无止境的，以抵抗控制损害。以此目的，硬粒小麦–Aegilops speltoides在我们的广泛杂交计划中开发的回交基因渗入系（DS-BIL）在幼苗和成株阶段都针对条锈病和白粉病进行了筛选。DS-BILs 在成年植物阶段表现出完全到中等的抗性，而在幼苗阶段则表现出不同的抗性和易感性。在 14 条染色体上共鉴定出 1095 个单核苷酸多态性 (SNP)硬粒小麦，通过测序使用基因分型，用于QTL作图。11 个独特的 QTL，跨越 6 个染色体（chr1B、chr2A、chr2B、chr3B、chr6B 和 chr7B）被鉴定为抗性，4 个 QTL 用于条锈病致病型田间混合，2 个 QTL 用于条锈病致病型 78S84，5 个 QTL 用于粉状锈病田间混合使用基于逐步回归的似然比检验标记的加性效应和单标记分析的霉菌病型。鉴定出携带多个 QTL 的 11 个 DS-BIL，这将作为一个有用的资源，将各自的抗性转移到易感品种上，以开发所有阶段抗性优良品种，其中 QTL 用于条锈病抗性QYrAs.pau-2A.1（LOD 3.8，PVE 24.51 与 SNP S2A_16016633 相关联）和抗白粉病的 QTLQPMAs.pau-6B（几率的对数 (LOD) 3.2，表型变异解释 (PVE) 17.75 与 SNP S6B_26793381 相关联）是转移的主要目标。