School of Agriculture, Center of Wheat Research, Henan Key Laboratory of Hybrid Wheat, Henan Key Laboratory for Molecular Ecology and Germplasm Innovation of Cotton and Wheat, Henan Institute of Science and Technology, Xinxiang, Henan, 453003, China.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
BMC Plant Biol. 2024 Jul 29;24(1):718. doi: 10.1186/s12870-024-05433-6.
Powdery mildew (caused by Blumeria graminis f. sp. tritici (Bgt)) and leaf rust (caused by Puccinia triticina (Pt)) are prevalent diseases in wheat (Triticum aestivum L.) production. Thinopyrum ponticum (2n = 10x = 70, EEEEEEStStStSt) contains genes that confer high levels of resistance to these diseases.
An elite wheat-Th. ponticum disomic substitution line, DS5Ag(5D), was developed in the Bainong Aikang 58 (AK58) background. The line was assessed using genomic in situ hybridization (GISH), oligo-nucleotide probe multiplex (ONPM) fluorescence in situ hybridization (FISH), and molecular markers. Twenty eight chromosome-specific molecular markers were identified for the alien chromosome, and 22 of them were co-dominant. Additionally, SNP markers from the wheat 660 K SNP chip were utilized to confirm chromosome identification and they provide molecular tools for tagging the chromosome in concern. The substitution line demonstrated high levels of resistance to powdery mildew throughout its growth period and to leaf rust at the adult stage. Based on the resistance evaluation of five F populations between the substitution lines and wheat genotypes with different levels of sensitivity to the two diseases. Results showed that the resistance genes located on 5Ag confered stable resistance against both diseases across different backgrounds. Resistance spectrum analysis combined with diagnostic marker detection of known resistance genes of Th. ponticum revealed that 5Ag contained two novel genes, Pm5Ag and Lr5Ag, which conferred resistance to powdery mildew and leaf rust, respectively.
In this study, a novel wheat-Th. ponticum disomic substitution line DS5Ag(5D) was successfully developed. The Th. ponticum chromosome 5Ag contain new resistance genes for powdery mildew and leaf rust. Chromosomic-specific molecular markers were generated and they can be used to track the 5Ag chromosome fragments. Consequently, this study provides new elite germplasm resources and molecular markers to facilitate the breeding of wheat varieties that is resistant to powdery mildew and leaf rust.
小麦白粉病（由禾本科布氏白粉菌小麦专化型引起（Bgt））和小麦叶锈病（由条形柄锈菌引起（Pt））是小麦生产中的常见病害。节节麦（2n=10x=70，EEEEEEEStStStSt）含有高水平抗这些病害的基因。
在白农安科 58（AK58）背景下，开发了一个小麦-节节麦二体异代换系 DS5Ag(5D)。该系通过基因组原位杂交（GISH）、寡核苷酸探针多重（ONPM）荧光原位杂交（FISH）和分子标记进行评估。鉴定出 28 个用于外源染色体的染色体特异性分子标记，其中 22 个为共显性标记。此外，还利用小麦 660K SNP 芯片的 SNP 标记来确认染色体鉴定，这些标记为相关染色体提供了标记工具。该代换系在整个生长期间对白粉病表现出高水平的抗性，在成株期对叶锈病也表现出抗性。基于代换系与对两种病害敏感性不同的小麦基因型之间的五个 F 群体的抗性评价。结果表明，5Ag 上的抗性基因在不同背景下均能稳定抗两种病害。结合对已知节节麦抗性基因的抗病谱分析和诊断标记检测，表明 5Ag 含有两个新的基因 Pm5Ag 和 Lr5Ag，分别对白粉病和叶锈病具有抗性。
本研究成功地开发了一个新的小麦-节节麦二体异代换系 DS5Ag(5D)。节节麦 5Ag 染色体含有对白粉病和叶锈病的新抗性基因。生成了染色体特异性分子标记，可用于跟踪 5Ag 染色体片段。因此，本研究为小麦抗白粉病和叶锈病的品种选育提供了新的优良种质资源和分子标记。
