Phytopathology. 2006 May;96(5):496-500. doi: 10.1094/PHYTO-96-0496.
ABSTRACT Powdery mildew, caused by Blumeria graminis f. sp tritici, is an important foliar disease of wheat worldwide. Pyramiding race-specific genes into a single cultivar and combining race-specific resistance genes with durable resistance genes are the preferred strategies to improve the durability of powdery mildew resistance. The objectives of this study were to characterize a powdery mildew resistance gene in Suwon 92 and identify gene-specific or tightly linked molecular markers for marker-assisted selection (MAS). A population of recombinant inbred lines (RILs) was derived by single seed descent from a cross between Suwon 92 and a susceptible cultivar, CI 13227. The RILs were screened for adult-plant infection type of powdery mildew and characterized with amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. The linked markers explained 41.3 to 69.2% of the phenotypic variances measured in 2 years. A morphological marker, hairy glume, was also associated with powdery mildew resistance in Suwon 92, and explained 43 to 51% of the phenotypic variance. The powdery mildew resistance gene in Suwon 92 was located on the short arm of chromosome 1A where Pm3 was located. Two gene-specific markers were developed based on the sequence of the cloned Pm3b gene. These two markers, which were mapped at the same locus in the peak region of the LOD score for the RIL population, explained most of the phenotypic variance for powdery mildew resistance in the RIL population. The powdery mildew resistance in Suwon 92 is most likely conditioned by the Pm3 locus. The gene markers developed herein can be directly used for MAS of some of the Pm3 alleles in breeding programs.
禾布氏白粉菌引起的小麦白粉病是全球范围内小麦的一种重要叶部病害。将专化性基因聚合到单一品种中，并将专化性抗性基因与持久性抗性基因相结合，是提高白粉病抗性持久性的首选策略。本研究的目的是鉴定韩国品种‘水源 92’中一个白粉病抗性基因，并鉴定与该基因紧密连锁的或基因特异性的分子标记，用于辅助选择（MAS）。通过单粒传衍生自‘水源 92’和易感品种 CI 13227 的杂交后代重组自交系（RIL）群体，对其进行白粉病成株期侵染型筛选，并利用扩增片段长度多态性（AFLP）和简单序列重复（SSR）标记进行鉴定。在 2 年的试验中，这些连锁标记解释了 41.3%至 69.2%的表型方差。‘水源 92’中的一个形态标记——长芒，也与白粉病抗性相关，解释了 43%至 51%的表型方差。‘水源 92’中的白粉病抗性基因位于 1A 染色体的短臂上，Pm3 就位于该位置。根据克隆的 Pm3b 基因序列开发了两个基因特异性标记。这两个标记在 RIL 群体的 LOD 得分峰值区域的相同位点上定位，解释了 RIL 群体中白粉病抗性的大部分表型方差。‘水源 92’中的白粉病抗性很可能由 Pm3 位点决定。本研究开发的基因标记可直接用于一些 Pm3 等位基因在育种计划中的 MAS。
