Page Rae, Huang Shuyi, Ronen Moshe, Sela Hanan, Sharon Amir, Shrestha Sandesh, Poland Jesse, Steffenson Brian J
Department of Plant Pathology, University of Minnesota, Saint Paul, MN, United States.
Institute for Cereal Crops Research, Tel Aviv University, Tel Aviv, Israel.
Front Plant Sci. 2023 Jul 27;14:1196486. doi: 10.3389/fpls.2023.1196486. eCollection 2023.
The rust diseases, including leaf rust caused by (), stem rust caused by f. sp. (), and stripe rust caused by f. sp. (), are major limiting factors in wheat production worldwide. Identification of novel sources of rust resistance genes is key to developing cultivars resistant to rapidly evolving pathogen populations. is a diploid wild grass native to the Levant and closely related to the modern bread wheat D subgenome. To explore resistance genes in the species, we evaluated a large panel of for resistance to several races of , , and , and conducted a genome-wide association study (GWAS) to map rust resistance loci in the species. A panel of 404 accessions, mostly collected from Israel, were screened for seedling-stage resistance to four races of , four races of , and three races of . Out of the 404 accessions screened, two were found that were resistant to all 11 races of the three rust pathogens screened. The percentage of all accessions screened that were resistant to a given rust pathogen race ranged from 18.5% to 99.7%. Genotyping-by-sequencing (GBS) was performed on 381 accessions of the panel, wherein 125,343 single nucleotide polymorphisms (SNPs) were obtained after alignment to the reference genome assembly and quality control filtering. Genetic diversity analysis revealed the presence of two distinct subpopulations, which followed a geographic pattern of a northern and a southern subpopulation. Association mapping was performed in the genotyped portion of the collection (n = 381) and in each subpopulation (n = 204 and 174) independently via a single-locus mixed-linear model, and two multi-locus models, FarmCPU, and BLINK. A large number (195) of markers were significantly associated with resistance to at least one of 10 rust pathogen races evaluated, nine of which are key candidate markers for further investigation due to their detection via multiple models and/or their association with resistance to more than one pathogen race. The novel resistance loci identified will provide additional diversity available for use in wheat breeding.
锈病，包括由（）引起的叶锈病、由禾柄锈菌小麦专化型（）引起的茎锈病以及由条形柄锈菌小麦专化型（）引起的条锈病，是全球小麦生产的主要限制因素。鉴定新的抗锈病基因来源是培育能够抵御快速进化的病原菌群体的品种的关键。野生二粒小麦是一种原产于黎凡特的二倍体野草，与现代面包小麦的D亚基因组密切相关。为了探索该物种中的抗性基因，我们评估了一大组野生二粒小麦对叶锈菌、茎锈菌和条锈菌的几个生理小种的抗性，并进行了全基因组关联研究（GWAS）以定位该物种中的抗锈病基因座。对一组主要从以色列收集的404份野生二粒小麦材料进行了苗期对4个叶锈菌生理小种、4个茎锈菌生理小种和3个条锈菌生理小种的抗性筛选。在筛选的404份材料中，发现有两份对所筛选的三种锈病病原菌的所有11个生理小种均具有抗性。所筛选的所有材料中对给定锈病病原菌生理小种具有抗性的比例在18.5%至99.7%之间。对该野生二粒小麦材料组中的381份材料进行了简化基因组测序（GBS），在与野生二粒小麦参考基因组组装进行比对并经过质量控制筛选后，获得了125,343个单核苷酸多态性（SNP）。遗传多样性分析揭示存在两个不同的亚群，呈现出北方和南方亚群的地理分布模式。通过单基因座混合线性模型以及两种多基因座模型（FarmCPU和BLINK），在该群体的基因分型部分（n = 381）以及每个亚群（n = 204和174）中分别独立进行关联作图。大量（195个）标记与对所评估的10个锈病病原菌生理小种中至少一个的抗性显著相关，其中9个是进一步研究的关键候选标记，因为它们通过多种模型被检测到和/或与对多个病原菌生理小种的抗性相关。所鉴定出的新的抗性基因座将为小麦育种提供更多可用的多样性。
