CREA Research Centre for Genomics and Bioinformatics, 29017 Fiorenzuola d'Arda, Italy.
Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland.
Int J Mol Sci. 2021 Mar 18;22(6):3109. doi: 10.3390/ijms22063109.
Leaf rust and powdery mildew are two important foliar diseases in wheat. A recombinant inbred line (RIL) population, obtained by crossing two bread wheat cultivars ('Victo' and 'Spada'), was evaluated for resistance to the two pathogens at seedling stage. Upon developing a genetic map of 8726 SNP loci, linkage analysis identified three resistance Quantitative Trait Loci (QTLs), with 'Victo' contributing the resistant alleles to all loci. One major QTL (Qgb-7A) was detected in response to on chromosome 7A, which explained 90% of phenotypic variation (PV). The co-positional relationship with known powdery mildew () resistance loci suggested that a new source of resistance was identified in . Two QTLs were detected in response to : a major gene on chromosome 5D (Q.gb-5D), explaining a total PV of about 59%, and a minor QTL on chromosome 2B (Q.gb-2B). A positional relationship was observed between the Q.gb-5D with the known 1 gene, but polymorphisms were found between the cloned 1 and the corresponding 'Victo' allele, suggesting that Q.gb-5D could represent a new functional 1 allele. Lastly, upon anchoring the QTL on the reference genome, candidate genes were hypothesized on the basis of gene annotation and in silico gene expression analysis.
叶锈病和白粉病是小麦的两种重要叶部病害。通过杂交两个面包小麦品种（“Victo”和“Spada”）获得重组自交系（RIL）群体，在幼苗期评估其对两种病原体的抗性。在开发了 8726 个 SNP 标记的遗传图谱后，连锁分析鉴定出三个抗性数量性状基因座（QTL），其中“Victo”为所有位点提供了抗性等位基因。在 7A 染色体上检测到一个主要的 QTL（Qgb-7A），对 有反应，解释了 90%的表型变异（PV）。与已知白粉病（）抗性基因座的共定位关系表明，在 中鉴定到了一个新的抗性来源。在响应 时检测到两个 QTL：一个位于 5D 染色体上的主基因（Q.gb-5D），解释总 PV 约 59%，另一个位于 2B 染色体上的微效 QTL（Q.gb-2B）。在 Q.gb-5D 与已知 1 基因之间观察到位置关系，但在克隆的 1 基因和相应的“Victo”等位基因之间发现了多态性，表明 Q.gb-5D 可能代表一个新的功能性 1 等位基因。最后，在将 QTL 锚定在 参考基因组上后，根据基因注释和计算机基因表达分析假设候选基因。
