National Agricultural Biotechnology Research Center, Holeta, Ethiopian Institute of Agricultural Research, Addis Ababa, Ethiopia.
International Maize and Wheat Improvement Center (CIMMYT), Addis Ababa, Ethiopia.
PLoS One. 2021 May 17;16(5):e0243675. doi: 10.1371/journal.pone.0243675. eCollection 2021.
Durum wheat is an important cereal grown in Ethiopia, a country which is also its center for genetic diversity. Yellow (stripe) rust caused by Puccinia striiformis fsp tritici is one of the most devastating diseases threatening Ethiopian wheat production. To identify sources of genetic resistance and combat this pathogen, we conducted a genome wide association study of yellow rust resistance on 300 durum wheat accessions comprising 261 landraces and 39 cultivars. The accessions were evaluated for their field resistance using a modified Cobb scale at Meraro, Kulumsa and Chefe Donsa in the 2015 and 2016 main growing seasons. Analysis of the 35K Axiom Array genotyping data of the panel resulted in a total of 8,797 polymorphic SNPs of which 7,093 were used in subsequent analyses. Population structure analysis suggested two groups in which the cultivars clearly stood out separately from the landraces. Eleven SNPs significantly associated with yellow rust resistance were identified on four chromosomes (1A, 1B, 2B, and 5A) which defined at least five genomic loci. Six of the SNPs were consistently identified on chromosome 1B singly at each and combined overall environments which explained 62.6-64.0% of the phenotypic variation (R2). Resistant allele frequency ranged from 14.0-71.0%; Zooming in to the identified resistance loci revealed the presence of disease resistance related genes involved in the plant defense system such as the ABC transporter gene family, disease resistance protein RPM1 (NBS-LRR class), Receptor kinases and Protein kinases. This study has provided SNPs for tracking the loci associated with yellow rust resistance and a diversity panel which can be used for association study of other agriculturally important traits in durum wheat.
硬粒小麦是埃塞俄比亚种植的一种重要谷物，也是其遗传多样性的中心。由条形柄锈菌引起的黄（条）锈病是威胁埃塞俄比亚小麦生产的最具破坏性的疾病之一。为了鉴定遗传抗性来源并对抗这种病原体，我们对 300 份硬粒小麦进行了全基因组关联研究，其中包括 261 份地方品种和 39 份栽培品种。这些品种在 Meraro、Kulumsa 和 Chefe Donsa 的主要生长季节（2015 年和 2016 年）使用改良的 Cobb 量表进行了田间抗性评估。对该小组的 35K Axiom Array 基因分型数据进行分析，共产生了 8797 个多态性 SNP，其中 7093 个 SNP 用于后续分析。群体结构分析表明，存在两个群体，其中品种明显与地方品种分开。在四个染色体（1A、1B、2B 和 5A）上鉴定出 11 个与黄锈病抗性显著相关的 SNP，这些 SNP 定义了至少五个基因组位点。其中 6 个 SNP 分别在每个染色体 1B 上单独鉴定出，在综合环境中解释了 62.6-64.0%的表型变异（R2）。抗性等位基因频率范围为 14.0-71.0%；在鉴定的抗性位点上进行放大，揭示了存在与植物防御系统相关的疾病抗性相关基因，如 ABC 转运蛋白基因家族、疾病抗性蛋白 RPM1（NBS-LRR 类）、受体激酶和蛋白激酶。本研究提供了与黄锈病抗性相关的基因座的 SNP，以及一个可用于硬粒小麦其他农业重要性状关联研究的多样性小组。
