Atsbeha Genet, Mekonnen Tilahun, Kebede Mulugeta, Haileselassie Teklehaimanot, Goodwin Stephen B, Tesfaye Kassahun
Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia.
Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.
Front Plant Sci. 2023 Dec 7;14:1256770. doi: 10.3389/fpls.2023.1256770. eCollection 2023.
Stripe rust, caused by f. sp. , is a severe disease in wheat worldwide, including Ethiopia, causing up to 100% wheat yield loss in the worst season. The use of resistant cultivars is considered to be the most effective and durable management technique for controlling the disease. Therefore, the present study targeted the genetic architecture of adult plant resistance to yellow rust in 178 wheat association panels. The panel was phenotyped for yellow rust adult-plant resistance at three locations. Phonological, yield, yield-related, and agro-morphological traits were recorded. The association panel was fingerprinted using the genotyping-by-sequencing (GBS) platform, and a total of 6,788 polymorphic single nucleotide polymorphisms (SNPs) were used for genome-wide association analysis to identify effective yellow rust resistance genes. The marker-trait association analysis was conducted using the Genome Association and Prediction Integrated Tool (GAPIT). The broad-sense heritability for the considered traits ranged from 74.52% to 88.64%, implying the presence of promising yellow rust resistance alleles in the association panel that could be deployed to improve wheat resistance to the disease. The overall linkage disequilibrium (LD) declined within an average physical distance of 31.44 Mbp at r= 0.2. Marker-trait association (MTA) analysis identified 148 loci significantly ( = 0.001) associated with yellow rust adult-plant resistance. Most of the detected resistance quantitative trait loci (QTLs) were located on the same chromosomes as previously reported QTLs for yellow rust resistance and mapped on chromosomes 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 3D, 4A, 4B, 4D, 5A, 5B, 6A, 6B, 7A, and 7D. However, 12 of the discovered MTAs were not previously documented in the wheat literature, suggesting that they could represent novel loci for stripe rust resistance. Zooming into the QTL regions in IWGSC RefSeq Annotation v1 identified crucial disease resistance-associated genes that are key in plants' defense mechanisms against pathogen infections. The detected QTLs will be helpful for marker-assisted breeding of wheat to increase resistance to stripe rust. Generally, the present study identified putative QTLs for field resistance to yellow rust and some important agronomic traits. Most of the discovered QTLs have been reported previously, indicating the potential to improve wheat resistance to yellow rust by deploying the QTLs discovered by marker-assisted selection.
条锈病由小麦条锈菌引起，是一种在全球范围内包括埃塞俄比亚在内的小麦严重病害，在最严重的季节可导致高达100%的小麦产量损失。使用抗病品种被认为是控制该病害最有效且持久的管理技术。因此，本研究针对178个小麦关联群体中成年植株对条锈病的抗性遗传结构展开研究。该群体在三个地点进行了条锈病成年植株抗性的表型分析。记录了物候、产量、产量相关及农艺形态性状。利用简化基因组测序（GBS）平台对关联群体进行指纹图谱分析，并使用总共6788个多态性单核苷酸多态性（SNP）进行全基因组关联分析，以鉴定有效的条锈病抗性基因。使用基因组关联与预测整合工具（GAPIT）进行标记-性状关联分析。所考虑性状的广义遗传力范围为74.52%至88.64%，这意味着关联群体中存在有前景的条锈病抗性等位基因，可用于提高小麦对该病害的抗性。在r = 0.2时，整体连锁不平衡（LD）在平均物理距离31.44 Mbp内下降。标记-性状关联（MTA）分析确定了148个与条锈病成年植株抗性显著相关（P = 0.001）的位点。大多数检测到的抗性数量性状位点（QTL）位于与先前报道的条锈病抗性QTL相同的染色体上，并定位在1A、1B、1D、2A、2B、2D、3A、3B、3D、4A、4B、4D、5A、5B、6A、6B、7A和7D染色体上。然而，发现的12个MTA此前在小麦文献中未被记载，这表明它们可能代表条锈病抗性的新位点。在国际小麦基因组测序联盟（IWGSC）参考序列注释v1中放大QTL区域，鉴定出了在植物抵御病原体感染的防御机制中起关键作用的重要抗病相关基因。检测到的QTL将有助于小麦的标记辅助育种，以提高对条锈病的抗性。总体而言，本研究鉴定了田间条锈病抗性和一些重要农艺性状的假定QTL。大多数发现的QTL此前已有报道，这表明通过标记辅助选择发现的QTL来提高小麦对条锈病的抗性具有潜力。
