Department of Plant Genetics and Breeding/State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, 100193, China.
Theor Appl Genet. 2015 Feb;128(2):365-73. doi: 10.1007/s00122-014-2436-2. Epub 2014 Dec 4.
A powdery mildew resistance gene MlHLT derived from a Chinese wheat landrace maps within a 3.6 centimorgan (cM) genetic interval spanning a 13.4 megabase (Mb) physical genomic region on chromosome 1DS. Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt) is a devastating disease that can cause severe yield losses. Chinese wheat landrace Hulutou confers nearly immune resistance against prevailing Bgt isolate E09 in Beijing. Genetic analysis indicate that the powdery mildew resistance of Hulutou is controlled by a single dominant gene, provisionally designated MlHLT. Bulked segregant analysis(BSA) and simple sequence repeat (SSR) mapping showed that MlHLT is located on chromosome arm 1DS between markers Xgwm337 and Xcfd83/Xcfd72. By applying comparative genomics analysis, collinearity genomic regions of the MlHLT locus on Aegilops tauschii chromosome 1DS were identified in Brachypodium distachyon chromosome 2, rice chromosome 5 and sorghum chromosome 9, respectively. Three new polymorphic markers were developed using the draft genome sequences and the extended single nucleotide polymorphism (SNP) marker sequences of Ae. tauschii accession AL8/78, as well as the Triticum aestivum cv. Chinese Spring 454 contig sequences and the International Wheat Genome Sequencing Consortium (IWGSC) survey sequences. MlHLT mapped into a 3.6 cM genetic interval spanning 13.4 Mb physical genomic region containing seven contigs (ctg220, ctg4623, ctg1063, ctg5929, ctg3163, ctg699 and ctg1065) on 1DS that has synteny with a 369.8 kb genomic region in Brachypodium, a 380.8 kb genomic region in rice and a 298.4 kb genomic region in sorghum. The genetic and physical maps of MlHLT provide framework for map-based cloning and marker-assisted selection (MAS) of the powdery mildew resistance gene MlHLT in Hulutou.
一个源于中国小麦地方品种的抗白粉病基因 MlHLT 被定位在横跨小麦 1DS 染色体上 13.4Mb 物理基因组区域的 3.6cM 遗传区间内，该区间包含一个由 Blumeria graminis f. sp. tritici（Bgt）引起的白粉病，是一种破坏性疾病，可导致严重的产量损失。中国小麦地方品种“葫芦头”对北京流行的 Bgt 分离株 E09 具有几乎免疫的抗性。遗传分析表明，“葫芦头”的白粉病抗性由一个单一的显性基因控制，暂定名为 MlHLT。BSA 和 SSR 作图表明，MlHLT 位于 Xgwm337 和 Xcfd83/Xcfd72 标记之间的 1DS 染色体臂上。通过应用比较基因组学分析，在拟南芥 2 号染色体、水稻 5 号染色体和高粱 9 号染色体上分别鉴定出 MlHLT 基因座在粗山羊草 1DS 染色体上的共线性基因组区域。利用 Ae. tauschii accession AL8/78 的草图基因组序列和扩展的单核苷酸多态性（SNP）标记序列，以及 Triticum aestivum cv. Chinese Spring 454 连文序列和国际小麦基因组测序联盟（IWGSC）调查序列，开发了三个新的多态性标记。MlHLT 定位在一个跨越 13.4Mb 物理基因组区域的 3.6cM 遗传区间内，该区域包含 1DS 上的七个 contig（ctg220、ctg4623、ctg1063、ctg5929、ctg3163、ctg699 和 ctg1065），与拟南芥中的 369.8kb 基因组区域、水稻中的 380.8kb 基因组区域和高粱中的 298.4kb 基因组区域具有同源性。MlHLT 的遗传和物理图谱为“葫芦头”中白粉病抗性基因 MlHLT 的基于图谱的克隆和标记辅助选择（MAS）提供了框架。
