Oak Ridge Institute for Science and Education (ORISE) Research Participant, Small Grains and Potato Germplasm Research Unit, Aberdeen, Idaho, United States of America.
USDA-ARS, Plant Genetic Resources Unit, Geneva, New York, United States of America.
PLoS One. 2024 Feb 2;19(2):e0295006. doi: 10.1371/journal.pone.0295006. eCollection 2024.
Oat crown rust, caused by Puccinia coronata Corda f. sp. avenae Eriks. (Pca), is a major biotic impediment to global oat production. Crown rust resistance has been described in oat diploid species A. strigosa accession PI 258731 and resistance from this accession has been successfully introgressed into hexaploid A. sativa germplasm. The current study focuses on 1) mapping the location of QTL containing resistance and evaluating the number of quantitative trait loci (QTL) conditioning resistance in PI 258731; 2) understanding the relationship between the original genomic location in A. strigosa and the location of the introgression in the A. sativa genome; 3) identifying molecular markers tightly linked with PI 258731 resistance loci that could be used for marker assisted selection and detection of this resistance in diverse A. strigosa accessions. To achieve this, A. strigosa accessions, PI 258731 and PI 573582 were crossed to produce 168 F5:6 recombinant inbred lines (RILs) through single seed descent. Parents and RILs were genotyped with the 6K Illumina SNP array which generated 168 segregating SNPs. Seedling reactions to two isolates of Pca (races TTTG, QTRG) were conditioned by two genes (0.6 cM apart) in this population. Linkage mapping placed these two resistant loci to 7.7 (QTRG) to 8 (TTTG) cM region on LG7. Field reaction data was used for QTL analysis and the results of interval mapping (MIM) revealed a major QTL (QPc.FD-AS-AA4) for field resistance. SNP marker assays were developed and tested in 125 diverse A. strigosa accessions that were rated for crown rust resistance in Baton Rouge, LA and Gainesville, FL and as seedlings against races TTTG and QTRG. Our data proposed SNP marker GMI_ES17_c6425_188 as a candidate for use in marker-assisted selection, in addition to the marker GMI_ES02_c37788_255 suggested by Rine's group, which provides an additional tool in facilitating the utilization of this gene in oat breeding programs.
燕麦冠锈病，由 Puccinia coronata Corda f. sp. avenae Eriks. (Pca) 引起，是全球燕麦生产的主要生物障碍。燕麦二倍体物种 A. strigosa accession PI 258731 中已描述了冠锈病抗性，并且该抗性已成功导入六倍体 A. sativa 种质中。本研究重点关注：1）定位含有抗性的 QTL 位置，并评估 PI 258731 中抗性的数量性状位点（QTL）数量；2）了解 A. strigosa 原始基因组位置与 A. sativa 基因组中导入位置之间的关系；3）鉴定与 PI 258731 抗性位点紧密连锁的分子标记，可用于标记辅助选择和检测不同 A. strigosa 材料中的抗性。为此，将 A. strigosa accession PI 258731 和 PI 573582 与亲本进行杂交，通过单粒传代产生 168 个 F5:6 重组自交系（RILs）。利用 6K Illumina SNP 芯片对亲本和 RILs 进行基因型分析，共产生 168 个分离 SNP。在该群体中，两个 Pca 分离株（race TTTG，QTRG）的幼苗反应由两个基因（相距 0.6 cM）决定。连锁作图将这两个抗性基因定位于 LG7 的 7.7（QTRG）至 8（TTTG）cM 区域。利用田间反应数据进行 QTL 分析，区间作图（MIM）的结果显示，一个主要的 QTL（QPc.FD-AS-AA4）对田间抗性具有显著作用。开发并测试了 SNP 标记在 125 个不同的 A. strigosa accessions 中的应用，这些 accessions 在 Baton Rouge, LA 和 Gainesville, FL 进行了冠锈病抗性评价，并作为幼苗对 race TTTG 和 QTRG 进行了评价。我们的数据提出 SNP 标记 GMI_ES17_c6425_188 作为标记辅助选择的候选标记，此外，Rine 小组提出的标记 GMI_ES02_c37788_255 也为标记辅助选择提供了另一个工具，这为在燕麦育种计划中利用该基因提供了更多的工具。
