PDF(Pubmed)
Abstract：
Leaf rust (LR) caused by Puccinia hordei is a serious disease of barley worldwide, causing significant yield losses and reduced grain quality. Discovery and incorporation of new sources of resistance from gene bank accessions into barley breeding programs is essential for the development of leaf rust resistant varieties. To identify Quantitative Trait Loci (QTL) conferring LR resistance in the two barley subsets, the Generation Challenge Program (GCP) reference set of 142 accessions and the leaf rust subset constructed using the Focused Identification of Germplasm Strategy (FIGS) of 76 barley accessions, were genotyped to conduct a genome-wide association study (GWAS). The results revealed a total of 59 QTL in the 218 accessions phenotyped against barley leaf rust at the seedling stage using two P. hordei isolates (ISO-SAT and ISO-MRC), and at the adult plant stage in four environments in Morocco. Out of these 59 QTL, 10 QTL were associated with the seedling resistance (SR) and 49 QTL were associated with the adult plant resistance (APR). Four QTL showed stable effects in at least two environments for APR, whereas two common QTL associated with SR and APR were detected on chromosomes 2H and 7H. Furthermore, 39 QTL identified in this study were potentially novel. Interestingly, the sequences of 27 SNP markers encoded the candidate genes (CGs) with predicted protein functions in plant disease resistance. These results will provide new perspectives on the diversity of leaf rust resistance loci for fine mapping, isolation of resistance genes, and for marker-assisted selection for the LR resistance in barley breeding programs worldwide.
摘要：
大麦Pucchiniahordei引起的叶锈病（LR）是世界范围内大麦的严重疾病，造成显著的产量损失和谷物质量下降。从基因库种质中发现新的抗性来源并将其纳入大麦育种计划对于开发抗叶锈病品种至关重要。为了在两个大麦亚群中鉴定赋予LR抗性的数量性状基因座（QTL），世代挑战计划（GCP）参考集的142个种质和叶锈病子集，使用集中鉴定种质策略（图）的76个大麦种质，进行全基因组关联研究(GWAS)。结果表明，在苗期使用两个大麦P.hordei分离株（ISO-SAT和ISO-MRC）针对大麦叶锈病的218种表型中，共有59个QTL，在摩洛哥的四个环境中处于成年植物阶段。在这59个QTL中，10个QTL与幼苗抗性（SR）相关，49个QTL与成株抗性（APR）相关。四个QTL在至少两个环境中对APR显示出稳定的作用，而在2H和7H染色体上检测到与SR和APR相关的两个常见QTL。此外，本研究中鉴定出的39个QTL可能是新的。有趣的是,27个SNP标记的序列编码候选基因（CGs），具有预测的植物抗病性蛋白质功能。这些结果将为精细作图研究叶片锈病抗性位点的多样性提供新的视角，抗性基因的分离，并用于全球大麦育种计划中LR抗性的标记辅助选择。
