Ouyang Shuhong, Zhang Dong, Han Jun, Zhao Xiaojie, Cui Yu, Song Wei, Huo Naxin, Liang Yong, Xie Jingzhong, Wang Zhenzhong, Wu Qiuhong, Chen Yong-Xing, Lu Ping, Zhang De-Yun, Wang Lili, Sun Hua, Yang Tsomin, Keeble-Gagnere Gabriel, Appels Rudi, Doležel Jaroslav, Ling Hong-Qing, Luo Mingcheng, Gu Yongqiang, Sun Qixin, Liu Zhiyong
State Key Laboratory for Agrobiotechnology/Beijing Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Heterosis Research & Utilization, Ministry of Education, China Agricultural University, Beijing, China.
State Key Laboratory for Agrobiotechnology/Beijing Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Heterosis Research & Utilization, Ministry of Education, China Agricultural University, Beijing, China; Agriculture University of Beijing, Beijing, China.
PLoS One. 2014 Jun 23;9(6):e100160. doi: 10.1371/journal.pone.0100160. eCollection 2014.
Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most important wheat diseases in the world. In this study, a single dominant powdery mildew resistance gene MlIW172 was identified in the IW172 wild emmer accession and mapped to the distal region of chromosome arm 7AL (bin7AL-16-0.86-0.90) via molecular marker analysis. MlIW172 was closely linked with the RFLP probe Xpsr680-derived STS marker Xmag2185 and the EST markers BE405531 and BE637476. This suggested that MlIW172 might be allelic to the Pm1 locus or a new locus closely linked to Pm1. By screening genomic BAC library of durum wheat cv. Langdon and 7AL-specific BAC library of hexaploid wheat cv. Chinese Spring, and after analyzing genome scaffolds of Triticum urartu containing the marker sequences, additional markers were developed to construct a fine genetic linkage map on the MlIW172 locus region and to delineate the resistance gene within a 0.48 cM interval. Comparative genetics analyses using ESTs and RFLP probe sequences flanking the MlIW172 region against other grass species revealed a general co-linearity in this region with the orthologous genomic regions of rice chromosome 6, Brachypodium chromosome 1, and sorghum chromosome 10. However, orthologous resistance gene-like RGA sequences were only present in wheat and Brachypodium. The BAC contigs and sequence scaffolds that we have developed provide a framework for the physical mapping and map-based cloning of MlIW172.
由小麦白粉菌引起的白粉病是世界上最重要的小麦病害之一。在本研究中，在IW172野生二粒小麦材料中鉴定出一个单一显性抗白粉病基因MlIW172，并通过分子标记分析将其定位到染色体臂7AL的远端区域（bin7AL - 16 - 0.86 - 0.90）。MlIW172与RFLP探针Xpsr680衍生的STS标记Xmag2185以及EST标记BE405531和BE637476紧密连锁。这表明MlIW172可能与Pm1位点等位，或者是一个与Pm1紧密连锁的新位点。通过筛选硬粒小麦品种Langdon的基因组BAC文库和六倍体小麦品种中国春的7AL特异性BAC文库，并分析包含标记序列的乌拉尔图小麦基因组支架，开发了额外的标记，以构建MlIW172位点区域的精细遗传连锁图谱，并将抗性基因定位在0.48 cM的区间内。利用MlIW172区域侧翼的EST和RFLP探针序列与其他禾本科物种进行比较遗传学分析，结果显示该区域与水稻第6染色体、短柄草第1染色体和高粱第10染色体的直系同源基因组区域具有普遍的共线性。然而，直系同源抗性基因类似RGA序列仅存在于小麦和短柄草中。我们构建的BAC重叠群和序列支架为MlIW172的物理定位和图位克隆提供了框架。
