Center for Applied Plant Science and Center for Soybean Research, The Ohio State University, Columbus, Ohio, United States of America.
Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio, United States of America.
PLoS One. 2020 Mar 20;15(3):e0227710. doi: 10.1371/journal.pone.0227710. eCollection 2020.
Phytophthora sojae is one of the costliest soybean pathogens in the US. Quantitative disease resistance (QDR) is a vital part of Phytophthora disease management. In this study, QDR was measured in 478 and 495 plant introductions (PIs) towards P. sojae isolates OH.121 and C2.S1, respectively, in genome-wide association (GWA) analyses to identify genetic markers linked to QDR loci (QDRL). Populations were generated by sampling PIs from the US, the Republic of Korea, and the full collection of PIs maintained by the USDA. Additionally, a meta-analysis of QDRL reported from bi-parental studies was done to compare past and present findings. Twenty-four significant marker-trait associations were identified from the 478 PIs phenotyped with OH.121, and an additional 24 marker-trait associations were identified from the 495 PIs phenotyped with C2.S1. In total, 48 significant markers were distributed across 16 chromosomes and based on linkage analysis, represent a total of 44 QDRL. The majority of QDRL were identified with only one of the two isolates, and only a region on chromosome 13 was consistently identified. Regions on chromosomes 3, 13, and 17 were identified in previous GWA-analyses and were re-identified in this study. Five QDRL co-localized with P. sojae meta-QDRL identified from QDRL reported in previous biparental mapping studies. The remaining regions represent novel QDRL, in the soybean-P. sojae pathosystem and were primarily identified in germplasm from the Republic of Korea. Overall, the number of loci identified in this study highlights the complexity of QDR to P. sojae.
大豆疫霉是美国最昂贵的大豆病原体之一。定量疾病抗性（QDR）是大豆疫霉病管理的重要组成部分。在这项研究中，通过全基因组关联（GWA）分析对 478 个和 495 个植物引种（PI）对大豆疫霉 OH.121 和 C2.S1 分离物进行了 QDR 测量，以鉴定与 QDR 位点（QDRL）相关的遗传标记。这些群体是通过从美国、韩国和美国农业部维持的整个 PI 收藏中抽样 PI 生成的。此外，还对来自双亲和研究的 QDRL 的元分析进行了比较过去和现在的发现。在对 OH.121 表型的 478 个 PI 中，鉴定出了 24 个显著的标记-性状关联，在对 C2.S1 表型的 495 个 PI 中，又鉴定出了 24 个显著的标记-性状关联。总共鉴定出了 48 个显著标记，分布在 16 条染色体上，根据连锁分析，共代表 44 个 QDRL。大多数 QDRL 仅与两种分离物中的一种鉴定，只有 13 号染色体上的一个区域始终被鉴定出来。在之前的 GWA 分析中鉴定出的 3、13 和 17 号染色体区域在本研究中也得到了重新鉴定。5 个 QDRL 与先前双亲缘作图研究中报道的大豆疫霉元 QDRL 共定位。其余区域代表大豆-大豆疫霉系统中的新 QDRL，主要在韩国的种质资源中鉴定出来。总的来说，本研究中鉴定出的位点数量突出了大豆疫霉对 QDR 的复杂性。
