Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China.
Plant Dis. 2018 May;102(5):925-931. doi: 10.1094/PDIS-02-17-0199-RE. Epub 2018 Mar 8.
Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a serious disease of wheat (Triticum aestivum L.) throughout the world. Host resistance is the most effective and preferred means for managing this disease. Line 10V-2, a wheat breeding line with superior agronomic performance, shows broad-spectrum seedling resistance to powdery mildew. Genetic analysis demonstrated that its resistance was controlled by a single dominant gene, tentatively designated Pm10V-2. This gene was localized near the documented Pm2 locus on chromosome 5DS using the simple sequence repeat (SSR) marker Cfd81. To saturate the marker map of Pm10V-2, more markers were developed using bulked segregant RNA-Seq. Two single-nucleotide polymorphism (SNP) markers (Swgi047 and Swgi064), three expressed sequence tag markers (Swgi007, Swgi029, and Swgi038), and one SSR marker (Swgi066) were polymorphic between the resistant and susceptible bulks and showed tightly linked to the Pm10V-2 gene. Pm10V-2 was flanked by the new developed markers Swgi064 and Swgi066 at genetic distances of 0.4 and 1.2 centimorgans (cM), respectively, and cosegregated with Swgi007 and Swgi038. The homologous sequence of Pm2a was cloned from 10V-2 based on a recent study. Although the sequence cloned from 10V-2 was completely identical to that of the reported Pm2a-related gene, they did not cosegregate but were separated at a genetic distance of 1.6 cM, indicating that Pm10V-2 was different from the reported of Pm2a-related gene. When inoculated with multiple B. graminis f. sp. tritici isolates, Pm10V-2 had a significantly different resistance spectrum from Pm2a and other powdery mildew (Pm) resistance genes at or near the Pm2 locus. Therefore, Pm10V-2 may be a new Pm2 allele or Pm2-linked gene. To use Pm10V-2 in marker-assisted selection (MAS) breeding, seven markers applicable for MAS were confirmed, including three newly developed markers (Swgi029, Swgi038, and Swgi064) in the present work. Using these markers, a great number of resistant lines with desirable agronomic performance were selected from crosses involving 10V-2, including the breeding line KM5016, which has been entered in the Regional trials in Hebei Province, China.
小麦白粉病由禾布氏白粉菌引起，是一种严重影响小麦（Triticum aestivum L.）生长的疾病。利用寄主抗性是防治这种疾病最有效和首选的方法。10V-2 号小麦品系具有优异的农艺性能，对小麦白粉病表现出广谱的苗期抗性。遗传分析表明，其抗性由一个显性单基因控制，暂命名为 Pm10V-2。该基因位于 5DS 染色体上已定位的 Pm2 基因座附近，使用简单序列重复（SSR）标记 Cfd81 进行定位。为了饱和 Pm10V-2 的标记图谱，利用 bulked segregant RNA-Seq 开发了更多的标记。两个单核苷酸多态性（SNP）标记（Swgi047 和 Swgi064）、三个表达序列标签标记（Swgi007、Swgi029 和 Swgi038）和一个 SSR 标记（Swgi066）在抗性和感病群体之间表现多态性，且与 Pm10V-2 基因紧密连锁。Pm10V-2 由新开发的标记 Swgi064 和 Swgi066 侧翼，遗传距离分别为 0.4 和 1.2 厘摩（cM），与 Swgi007 和 Swgi038 共分离。根据最近的一项研究，从 10V-2 中克隆了 Pm2a 的同源序列。尽管从 10V-2 中克隆的序列与报道的 Pm2a 相关基因完全相同，但它们没有共分离，而是在遗传距离为 1.6 cM 处分离，表明 Pm10V-2 与报道的 Pm2a 相关基因不同。当接种多种禾布氏白粉菌时，Pm10V-2 在 Pm2 基因座或其附近的抗白粉病基因 Pm2a 和其他抗白粉病基因具有明显不同的抗性谱。因此，Pm10V-2 可能是一个新的 Pm2 等位基因或与 Pm2 连锁的基因。为了在标记辅助选择（MAS）育种中利用 Pm10V-2，本研究共鉴定了 7 个适用于 MAS 的标记，包括 3 个新开发的标记（Swgi029、Swgi038 和 Swgi064）。利用这些标记，从包含 10V-2 的杂交后代中选择了大量具有理想农艺性状的抗性品系，包括已进入中国河北省区域试验的 KM5016 品系。
