Wheat, Peanut, and Other Field Crops Research Unit, USDA-ARS, Stillwater, OK, 74075, USA.
Plant and Soil Science Department, Oklahoma State University, Stillwater, OK, 74078, USA.
Theor Appl Genet. 2019 Sep;132(9):2625-2632. doi: 10.1007/s00122-019-03377-2. Epub 2019 Jun 18.
A new powdery mildew resistance gene that can be readily used in wheat breeding, Pm65, was identified in the facultative wheat cultivar Xinmai 208 and mapped to the terminal region of chromosome 2AL. Wheat powdery mildew, a widely occurring disease caused by the biotrophic fungus Blumeriagraminis f. sp. tritici (Bgt), poses a serious threat to wheat production. A high breeding priority is to identify powdery mildew resistance genes that can be readily used either alone or in gene complexes involving other disease resistance genes. An F population and 227 F families derived from the cross Xinmai 208 × Stardust were generated to map a powdery mildew resistance gene in Xinmai 208, a high-yielding Chinese wheat cultivar. Genetic analysis indicated that Xinmai 208 carries a single dominant powdery mildew resistance gene, designated herein Pm65, and linkage analysis delimited Pm65 to a 0.5 cM interval covering 531.8 Kb (763,289,667-763,821,463 bp) on chromosome 2AL in the Chinese Spring reference sequence. An allelism test indicated that Pm65 is a new gene about 10.3 cM distal to the Pm4 locus. Pm65 was 0.3 cM proximal to Xstars355 and 0.2 cM distal to Xstars356. It conferred near-immunity to 19 of 20 Bgt isolates collected from different wheat-growing regions of the USA. Coming from a high-yield potential cultivar, Pm65 can be directly used to enhance powdery mildew resistance in wheat. The newly developed SSR markers Xstars355 and Xstars356 have the potential to tag Pm65 for wheat improvement.
一个新的、可在小麦育种中直接利用的抗白粉病基因 Pm65，被鉴定为兼性小麦品种新麦 208 中的一个基因，并被定位到染色体 2AL 的末端区域。小麦白粉病是一种由活体营养真菌小麦白粉菌（Blumeriagraminis f. sp. tritici，Bgt）引起的广泛发生的病害，对小麦生产构成严重威胁。一个高度的育种优先事项是识别可单独或与其他抗病基因的基因复合物一起使用的白粉病抗性基因。为了在新麦 208 中定位一个白粉病抗性基因，产生了一个由新麦 208×Stardust 杂交产生的 F 群体和 227 个 F 家系。新麦 208 是一个高产的中国小麦品种。遗传分析表明，新麦 208 携带一个单一的显性白粉病抗性基因，命名为 Pm65，连锁分析将 Pm65 限定在一个 0.5 cM 的区间内，包含中国春参考序列中染色体 2AL 上的 531.8 Kb（763,289,667-763,821,463 bp）。等位基因测试表明，Pm65 是一个新的基因，大约距离 Pm4 位点 10.3 cM 远。Pm65 与 Xstars355 近端 0.3 cM，与 Xstars356 远端 0.2 cM。它对来自美国不同小麦种植区的 20 个 Bgt 分离物中的 19 个表现出近免疫性。来自一个高产量潜力的品种，Pm65 可以直接用于增强小麦的白粉病抗性。新开发的 SSR 标记 Xstars355 和 Xstars356 有可能用于标记小麦改良中的 Pm65。
