Multi-locus genome-wide association studies to characterize Fusarium head blight (FHB) resistance in hard winter wheat

Authors: ZHANG, JINFENG - South Dakota State University; GILL, HARSIMARDEEP - South Dakota State University; HALDER, JYOTIRMOY - South Dakota State University; BRAR, NAVREET - South Dakota State University; SHAUKAT, ALI - South Dakota State University; Bernardo, Amy; St Amand, Paul; Bai, Guihua; TURNIPSEED, BRENT - South Dakota State University; SEHGAL, SUNISH - South Dakota State University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2022
Publication Date: 7/25/2022
Citation: Zhang, J., Gill, H., Halder, J., Brar, N., Shaukat, A., Bernardo, A.E., St Amand, P.C., Bai, G., Turnipseed, B., Sehgal, S. 2022. Multi-locus genome-wide association studies to characterize Fusarium head blight (FHB) resistance in hard winter wheat. Frontiers in Plant Science. 13. Article 946700. https://doi.org/10.3389/fpls.2022.946700.
DOI: https://doi.org/10.3389/fpls.2022.946700

Interpretive Summary: Fusarium head blight (FHB) of wheat often causes severe yield losses and serious grain quality concerns. In this study, we evaluated a panel of 257 wheat breeding lines from the South Dakota State University to identify native FHB resistance in US hard winter wheat using a multi-locus genome-wide association study. A total of six distinct partially effective resistance genes were identified for FHB disease index on chromosomes 2A, 2B, 3B, 4B, and 7A. Eight resistance genes on chromosomes 3B, 5A, 6B, 6D, 7A, and 7B were identified for Fusarium-damaged kernels. Among the 14 genes, ten were previously reported and the other four are likely novel resistance genes for FHB. The identified genes showed additive effects when combined. The resistance genes identified in this study would be useful resources for FHB resistance breeding via marker-assisted selection.

Technical Abstract: Fusarium head blight (FHB), caused by the fungus Fusarium graminearum is an important disease of wheat that causes severe yield losses along with serious quality concerns. Incorporating the host resistance from either wild relatives, landraces, or exotic materials remain challenging and has limited success. Therefore, a better understanding of the genetic basis of native FHB resistance in hard winter wheat (HWW) and combining it with major quantitative traits loci (QTLs) can facilitate the development of FHB resistant cultivars. In this study, we evaluated a panel of 257 breeding lines from the South Dakota State University (SDSU) breeding program to uncover the genetic basis of native FHB resistance in the US hard winter wheat. We conducted a multi-locus genome-wide association study (ML-GWAS) with 9,321 high-quality single nucleotide polymorphisms (SNPs) covering all 21 wheat chromosomes. A total of six distinct QTNs were identified for FHB disease index (DIS) on five different chromosomes including 2A, 2B, 3B, 4B, and 7A. Eight QTNs on six chromosomes 3B, 5A, 6B, 6D, 7A, and 7B were identified for Fusarium damaged kernels (FDK). Out of the 14 significant QTNs, ten QTNs previously reported from different wheat classes were validated in HWW, and the other four are likely novel genomic regions for FHB resistance. The additive effect of favorable alleles of the identified QTNs was significant as the combination of these QTNs resulted in lower mean DIS and FDK scores. Candidate gene analysis for two important QTNs identified several genes with putative proteins of interest and these genes need further investigation. The current study sheds light on the genetic basis of native FHB resistance in US HWW germplasm and the resistant lines and QTNs identified in this study would be useful resources for FHB resistance breeding via marker-assisted selection.