Small Grains and Potato Germplasm Research Unit, USDA-ARS, 1691 South 2700 West, Aberdeen, ID, 83210, USA.
Cereal Disease Laboratory, USDA-ARS, 1551 Lindig Street, St. Paul, MN, 55108, USA.
Theor Appl Genet. 2022 Apr;135(4):1307-1318. doi: 10.1007/s00122-022-04032-z. Epub 2022 Feb 3.
Comparative sequence analysis was used to design a SNP marker that aided in the identification of new sources of oat stem rust resistance. New races of Puccinia graminis f. sp. avenae (Pga) threaten global oat production. An A. strigosa accession known to carry the broadly effective oat stem rust resistance gene, Pg6, was crossed with two susceptible A. strigosa accessions to generate 198 F families and 190 F RILs. The RIL population was used to determine that Pg6 was a single dominant gene located between 475 and 491 Mbp on diploid chromosome AA2 of the A. atlantica genome. This region was further refined by identifying SNPs associated with Pg6 resistance in a panel of previously sequenced A-genome accessions. Twenty-four markers were developed from SNPs that showed perfect association between the Pg6 phenotype and 11 sequenced Avena diploid accessions. These markers were validated in the RILs and F families, and the markers most closely linked with resistance were tested in a diverse panel of 253 accessions consisting of oat stem rust differentials, all available diploid Avena spp. accessions, and 41 A. vaviloviana accessions from the National Small Grains Collection. One SNP marker located at 483, 439, 497 bp on AA2, designated as AA2_483439497, was perfectly associated with the Pg6 phenotype in Avena strigosa diploids and was within several Kb of a resistance gene analog, RPP13. The marker results and seedling testing against Pga races DBD, KBD, TJS, and TQL enabled the postulation of Pg6 and potential new sources of resistance in the Avena panel. These results will be used to infer Pg6 presence in other germplasm collections and breeding programs and can assist with introgression, gene pyramiding, and cloning of Pg6.
采用比较序列分析设计了一个 SNP 标记，用于鉴定新的燕麦抗秆锈病来源。新的禾柄锈菌 f. sp. avenae (Pga) 小种威胁着全球燕麦生产。一个已知携带广谱有效燕麦抗秆锈病基因 Pg6 的 A. strigosa 品系与两个易感的 A. strigosa 品系杂交，产生了 198 个 F 家系和 190 个 F RILs。利用 RIL 群体确定 Pg6 是一个位于二倍体 A. atlantica 基因组 AA2 染色体 475 到 491 Mbp 之间的单一显性基因。通过鉴定与 11 个已测序的 A 基因组品系中 Pg6 抗性相关的 SNP，进一步细化了该区域。从与 Pg6 表型之间存在完美关联的 SNP 中开发了 24 个标记，这些标记在 253 个燕麦品系中进行了验证，包括燕麦秆锈病鉴别品种、所有可利用的二倍体燕麦属品种和来自国家小谷物收藏的 41 个 A. vaviloviana 品系。一个位于 AA2 上 483、439、497 bp 的 SNP 标记，命名为 AA2_483439497，与 Avena strigosa 二倍体中的 Pg6 表型完全相关，并且在几个 Kb 范围内有一个抗性基因类似物 RPP13。该标记结果和对 Pga 小种 DBD、KBD、TJS 和 TQL 的幼苗测试，使我们能够推测 Avena 品系中存在 Pg6 和潜在的新的抗性来源。这些结果将用于推断其他种质资源收集和育种计划中 Pg6 的存在，并有助于 Pg6 的导入、基因聚合和克隆。
