Dissection of Fusarium head blight resistance in a modified nested association mapping panel of synthetic and bread wheat germplasm

Authors: KARMACHARYA, ANIL - University Of California, Davis; Lhamo, Dhondup; ACHARYA, KRISHNA - North Dakota State University; ZHANG, QIJUN - North Dakota State University; Chang, Han Chang; Zhong, Shaobin; GREEN, ANDREW - North Dakota State University; Fiedler, Jason; LUO, MINGCHENG - University Of California, Davis; Anderson, Kirk; Peters Haugrud, Amanda; ELIAS, ELIAS - North Dakota State University; ZHANG, XIAOFEI - University Of California, Davis; Gu, Yong; Xu, Steven

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/31/2025
Publication Date: 2/11/2026
Citation: Karmacharya, A., Lhamo, D., Acharya, K., Zhang, Q., Chang, H., Zhong, S., Green, A.J., Fiedler, J.D., Luo, M., Anderson, K.M., Peters Haugrud, A.R., Elias, E., Zhang, X., Gu, Y.Q., Xu, S.S. 2026. Dissection of Fusarium head blight resistance in a modified nested association mapping panel of synthetic and bread wheat germplasm. Journal of Theoretical and Applied Genetics. 139 Article 66. https://doi.org/10.1007/s00122-025-05148-8.
DOI: https://doi.org/10.1007/s00122-025-05148-8

Interpretive Summary: Fusarium head blight (FHB) is one of the most devastating diseases affecting wheat. Improving resistance to FHB has been a major focus of wheat genetics and breeding programs worldwide. However, only a limited number of major genes responsible for FHB resistance have been identified and effectively incorporated into modern wheat cultivars. To discover new FHB resistance genes and integrate them into contemporary wheat germplasm, we developed 276 hard red spring wheat (HRSW) lines by backcrossing four synthetic wheat lines with eight HRSW varieties/lines. After evaluating these lines for FHB resistance and conducting genetic analysis, we identified 17 wheat lines that exhibited a high level of resistance to FHB, along with 19 DNA markers that are significantly associated with this resistance. Among the 19 DNA markers, 16 were found to co-localize with previously reported FHB resistance genes, while three appear to be associated with novel genes for FHB resistance. The resistant lines developed in this study, along with the potentially novel genes identified, could serve as valuable resources for enhancing FHB resistance in wheat breeding programs.

Technical Abstract: Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most devastating diseases of wheat (Triticum aestivum) and other cereal crops worldwide. Improving FHB resistance has been a major focus in many wheat genetics and breeding programs globally. However, only a few major loci for FHB resistance have been effectively deployed. In this study, we developed a modified nested association mapping (NAM) panel comprising four synthetic hexaploid wheat (SHW) lines, eight hard red spring wheat (HRSW) varieties/lines, and their 276 BC1-derived lines. The panel was genotyped using the 90K SNP Infinium array and evaluated for Type II FHB resistance across four environments. The disease evaluations revealed that 17 wheat lines, primarily derived from backcrossing SHW line SW183 (T. dicoccum PI 191091/Aegilops tauschii CIae 26) with HRSW ‘Linkert’ or ‘Glenn’, exhibited resistance levels comparable to or exceeding that of the well-known FHB resistance source, Sumai 3. Through genome-wide association study (GWAS), we identified 19 significant marker-trait associations for FHB resistance. Among the 19 identified SNPs, three, two, and 14 carried resistance alleles derived from SHW, HRSW, and both parental sources, respectively. Of these SNP loci, 16 co-localized with previously reported FHB resistance QTL, while three, located on the short arms of chromosomes 1D, 2B, and 4A, respectively, are likely associated with novel loci for FHB resistance. The resistant lines developed in this study could serve as new sources for FHB resistance, and their associated resistance loci can be further validated and incorporated into breeding programs.