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Author ORCID Identifier

https://orcid.org/0009-0003-1712-4886

Date Available

7-31-2026

Year of Publication

2026

Document Type

Master's Thesis

Degree Name

Master's in Integrated Soil Sciences

College

Agriculture, Food and Environment

Department/School/Program

Plant and Soil Sciences

Faculty

David Van Sanford

Faculty

A. Hunt

Abstract

Soft red winter wheat (Triticum aestivum L.) is both an economically and nutritionally important crop in the global food supply. Despite its global importance, wheat is continually threatened by fungal diseases. Fusarium head blight (FHB), caused by Fusarium graminearum, is a devastating fungal disease affecting wheat worldwide, resulting in low yields, reduced test weight and mycotoxin production. The mycotoxin deoxynivalenol (DON) is toxic to humans, results in feed rejection in livestock, and is heavily monitored in the food supply. Because of wheat’s importance in the food system, post-harvest quality (milling, baking, and flavor) has been a growing area of research and has become an interest among breeders and consumers alike. Both disease resistance and wheat quality are important targets of wheat breeding programs. Additionally, the effect of nutrient management, specifically nitrogen, is important to consider. Thus, a series of studies was conducted to assess the effect of multiple FHB resistance QTL, the efficiency of using genomic predictions to select for post-harvest quality, and the effect of nitrogen availability on FHB-related and post-harvest quality traits. Collectively, results from this study provide breeders with practical strategies for improving FHB resistance, post-harvest quality, and agronomic performance in soft red winter wheat.

Deployment of FHB resistance QTL has played a crucial role in managing FHB and DON accumulation. However, there has been little research on the effect of different combinations of individual FHB resistance QTL on agronomic traits and disease management. A study was designed to investigate how various combinations of five FHB resistance QTL affect agronomic performance and disease management. By analyzing how F2 derived lines segregating for five FHB resistance QTL performed in four environments, we show that, in this population, Fhb1 was the most critical factor in lowering DON levels (P< 0.05) and maintaining high agronomic production. Using three training populations, genomic prediction models successfully captured 50% of the top performing lines. The KY and KY2 training populations favored Fhb1+1A Neuse+1B Jamestown whereas MDX favored Fhb1+1A Neuse+4A Neuse+1B Jamestown+3B Massey. These findings indicate that Fhb1 provides a superior baseline for resistance, and integrating genomic selection with strategic QTL pyramiding allows breeders to optimize FHB resistance without sacrificing agronomic productivity.

While efforts have been made to determine the feasibility of breeding for quality traits, the practicality of integrating them into a breeding pipeline by using genomic predictions has yet to be explored. We found low to moderate genomic prediction accuracies for milling and baking traits, with lactic acid solvent retention capacity and softness equivalent having the highest accuracies (r = 0.36 and r = 0.25, respectively). Flavor profiles also showed meaningful relationships with milling and baking quality traits. Sweet flavor profiles were positively correlated with softness equivalent (r = 0.39), while bitter flavor profiles were negatively correlated with lactic acid SRC (r = -0.47). With moderate genomic prediction accuracies and correlations between quality traits and flavor profiles, it is reasonable to use genomic predictions for lactic acid SRC and softness equivalent to select for improved flavor in wheat. Because milling, baking, and flavor evaluations are often time- and resource-intensive, genomic predictions provide breeders with a more efficient approach for integrating quality selection into breeding pipelines.

Lastly, a study was conducted to determine the impact of nitrogen management on soft red winter wheat quality and disease resistance. We found that increased nitrogen availability led to higher grain protein concentrations and increased sedimentation volume (P< 0.05). The magnitude of grain protein concentration and sedimentation volume responses varied by location, but positive trends were consistent across both sites. Crucially, this study found that nitrogen availability did not significantly affect DON accumulation or the prevalence of Fusarium damaged kernels. Variation in disease resistance was attributable to the presence of FHB resistance QTL. The results from this study support the notion that nitrogen fertilization can be used to enhance end-use quality without compromising disease management. The results also support that variety selection, and the utilization of FHB resistance QTL remain a priority for disease control.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2026.361

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Funding Information

This study was supported by the United States Wheat and Barley Scab Initiative Grant (no: 59-0206-9-054) from 2021 - 2025.

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