Ren Yueming, Luo Mengzhen, Feng Yajun, Chen Qifan, Ma Chao, Liu Wenxuan, Guo Fu, Liu Qianwen, Amjad Muhammad, Jia Ranran, He Xinpei, Ji Xiang, Zhao Yanlong, Kong Weixiu, Guo Mengqing, Tao Luna, Yang Zheng, Han Kai, Yin Guihong, Sehgal Sunish K, Zhao Yue, Zhang Jinpeng, Li Huanhuan
State Key Laboratory of High-Efficient Production of Wheat-Maize Double Cropping, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, Henan, China.
College of Agronomy, State Key Laboratory of High-Efficient Production of Wheat-Maize Double Cropping, Henan Agricultural University, State Wheat Engineering Technology Research Center, Zhengzhou, 450002, Henan, China.
Theor Appl Genet. 2025 Aug 25;138(9):228. doi: 10.1007/s00122-025-05015-6.
A novel powdery mildew resistance gene Pm7C from Aegilops caudata was introgressed into common wheat through ph1b-induced homoeologous recombination and mapped to the 7CL bin FL 0.90-0.96 on chromosome 7C. Wheat powdery mildew poses a significant threat to wheat grain yield and quality. Developing resistant wheat varieties through the deployment of resistance genes is the most effective, economically feasible, and environmentally sustainable strategy to combat this disease. Aegilops caudata (2n = 2x = 14, CC), a wild relative of common wheat, has been identified as a valuable genetic resource harboring novel resistance loci. Specifically, chromosome 7C of Ae. caudata carries a novel broad-spectrum resistance gene, tentatively designated as Pm7C. However, the structural variations in chromosome 7C, coupled with the unavailability of a reference genome for Ae. caudata, have hindered the introgression of this resistance gene into common wheat and its mapping. In this study, we report the development of wheat-Ae. caudata 7C recombinants via ph1b-induced homoeologous recombination and the cytological mapping of the resistance gene Pm7C. By integrating the analysis of 69 7C-specific markers with breakpoint mapping of 7C recombinants using in situ hybridization, we characterized 35 wheat-Ae. caudata 7C recombinants, categorizing them into 10 distinct types. This enabled the construction of a physical map of 7C, comprising nine chromosomal bins defined by 69 specific markers. Subsequent evaluation of powdery mildew resistance in these recombinants mapped Pm7C to the long arm of 7C within the interval of FL 0.90-0.96. Additionally, terminal recombinant 7CT1 (T7DL.7DS-7CL) and intercalary recombinant 7CT4 (Ti7DL.7DS-7CL-7DS) were identified as containing small 7CL segments that harbor Pm7C. These resources are expected to facilitate wheat disease-resistant breeding and further efforts in cloning and elucidating the resistance mechanism of Pm7C.
通过ph1b诱导的同源重组，将来自尾状山羊草的一个新型抗白粉病基因Pm7C导入普通小麦，并将其定位到7C染色体上的7CL区域，即FL 0.90 - 0.96区间。小麦白粉病对小麦籽粒产量和品质构成重大威胁。通过部署抗性基因培育抗病小麦品种是对抗这种病害最有效、经济可行且环境可持续的策略。尾状山羊草（2n = 2x = 14，CC）是普通小麦的野生近缘种，已被确定为具有新型抗性位点的宝贵遗传资源。具体而言，尾状山羊草的7C染色体携带一个新型广谱抗性基因，暂定为Pm7C。然而，7C染色体的结构变异以及尾状山羊草参考基因组的不可用，阻碍了该抗性基因导入普通小麦并进行定位。在本研究中，我们报告了通过ph1b诱导的同源重组培育小麦 - 尾状山羊草7C重组体以及抗白粉病基因Pm7C的细胞学定位。通过将69个7C特异性标记的分析与利用原位杂交对7C重组体的断点定位相结合，我们鉴定了35个小麦 - 尾状山羊草7C重组体，并将它们分为10种不同类型。这使得能够构建7C的物理图谱，该图谱由69个特异性标记定义的9个染色体区间组成。随后对这些重组体的白粉病抗性评估将Pm7C定位到7C长臂的FL 0.90 - 0.96区间内。此外，末端重组体7CT1（T7DL.7DS - 7CL）和中间重组体7CT4（Ti7DL.7DS - 7CL - 7DS）被鉴定为含有携带Pm7C的小7CL片段。这些资源有望促进小麦抗病育种以及进一步克隆和阐明Pm7C抗性机制的研究。
