Plant Breeding Institute, School of Life and Environmental Sciences, University of Sydney, Narellan, NSW 2567, Australia.
National Agricultural Research Organization, MbaZARDI, Mbarara City P.O. Box 389, Uganda.
Genes (Basel). 2024 May 3;15(5):583. doi: 10.3390/genes15050583.
Leaf rust caused by the pathogen () is a destructive fungal disease of wheat that occurs in almost all wheat-growing areas across the globe. Genetic resistance has proven to be the best solution to mitigate the disease. Wheat breeders are continuously seeking new diversified and durable sources of resistance to use in developing new varieties. We developed recombinant inbred line (RIL) populations from two leaf rust-resistant genotypes (Kenya Kudu and AUS12568) introduced from Kenya to identify and characterize resistance to and to develop markers linked closely to the resistance that was found. Our studies detected four QTL conferring adult plant resistance (APR) to leaf rust. Two of these loci are associated with known genes, and , residing on chromosomes 1B and 7B, respectively. The remaining two, and , contributed by Kenya Kudu and AUS12568 respectively, are putatively new loci for resistance. Both and were found to interact additively with in significantly reducing the disease severity at adult plant growth stages in the field. We further developed a suite of six closely linked markers within the locus and four within the region. Among these, markers and , flanking , and , distal to , were identified as the most closely linked and reliable for marker-assisted selection. The markers were validated on a selection of 64 Australian wheat varieties and found to be polymorphic and robust, allowing for clear allelic discrimination. The identified new loci and linked molecular markers will enable rapid adoption by breeders in developing wheat varieties carrying diversified and durable resistance to leaf rust.
由病原体 ()引起的叶锈病是一种破坏性的小麦真菌病，几乎发生在全球所有的小麦种植区。遗传抗性已被证明是减轻这种疾病的最佳方法。小麦育种者一直在寻找新的多样化和持久的抗性来源，用于开发新的品种。我们从肯尼亚引进了两种抗叶锈病基因型（肯尼亚库杜和 AUS12568），开发了重组自交系（RIL）群体，以鉴定和表征对 和开发与发现的抗性紧密连锁的标记。我们的研究检测到四个赋予成株期抗性（APR）的 QTL 对叶锈病。其中两个位点与已知基因 和 相关，分别位于 1B 和 7B 染色体上。其余两个由肯尼亚库杜和 AUS12568 提供的分别是 和 ，它们被认为是 抗性的新位点。 和 都被发现与 在显著降低田间成株生长阶段的病害严重度方面具有累加效应。我们进一步在 基因座内开发了一套 6 个紧密连锁的标记，在 区域内开发了 4 个标记。其中，标记 和 ，侧翼 和 ，位于 远端，被鉴定为最紧密连锁和可靠的用于标记辅助选择。这些标记在 64 种澳大利亚小麦品种的选择上进行了验证，发现它们是多态性和稳健的，允许清晰的等位基因区分。鉴定的新位点和连锁的分子标记将使育种者能够快速采用携带多样化和持久抗叶锈病的小麦品种。
