The University of Kentucky, in partnership with Kansas State University, Virginia Tech and the Federal University of Viçosa in Brazil, has been awarded a $686,010 grant to study the fungus Fusarium graminearum. This multi-institutional and international collaboration, titled “Selective Forces Impacting Fusarium graminearum Species Causing Gibberella Ear Rot in Maize,” aims to develop new tools and resources to monitor, model and manage Fusarium strains that cause significant diseases in corn. 

"Our research is particularly focused on the maize side of Fusarium graminearum's lifecycle,” said Lisa Vaillancourt, primary investigator and UK Martin-Gatton Department of Agriculture, Food and Environment plant pathology professor. “Understanding how this pathogen adapts and thrives on corn will be crucial for developing strategies to manage its spread and reduce its impact on both maize and wheat crops." 

The research primarily focuses on F. graminearum, a fungus responsible for Gibberella ear rot (GER) in maize and Fusarium head blight (FHB) in wheat. These diseases not only lead to severe yield losses but also contaminate grains with harmful mycotoxins, such as deoxynivalenol, which pose significant health risks to humans and animals, and which are subject to strict regulatory limits. 

Vaillancourt said international cooperation adds an important layer to the research. 

“The inclusion of the Brazilian partner is particularly crucial due to Brazil’s ability to cultivate corn year-round, which provides a unique opportunity to study the pathogen evolving over multiple generations under different environmental conditions and cropping practices,” she said. “This international partnership allows for a broader genetic analysis and more effective experimentation, enhancing the overall understanding of the pathogen.” 

Research Objectives: 

1. Genome sequencing and comparative analysis: The team will sequence and analyze the genomes of a diverse collection of F. graminearum isolates from maize and wheat. This genomic analysis will help identify genetic loci that undergo differential selection based on the host plant, providing insights into the pathogen’s adaptation mechanisms. 

2. Population dynamics and host selection: Researchers will study population shifts in F. graminearum by inoculating maize and wheat under continuous and rotational cropping regimes in different geographic locations. These experiments aim to identify the genetic changes and selective pressures exerted by different hosts, revealing how the pathogen evolves in response to varying agricultural practices. 

3. Controlled crosses and genetic characterization: Through controlled crosses between maize and wheat isolates, the study will characterize genetic regions associated with high levels of aggressiveness and toxigenicity. This will help determine whether the same genetic factors influence the pathogen’s virulence on both crops and explore potential fitness trade-offs associated with these traits. 

Given the increasing prevalence of GER in North America, particularly in the northern Corn Belt, the research will place a strong emphasis on understanding F. graminearum’s behavior in maize. Corn serves as a major reservoir for the fungus, facilitating its spread to wheat and other cereals. By focusing on maize, the researchers aim to uncover critical factors that drive the pathogen’s lifecycle and its impact on corn crops, which is crucial for developing effective management strategies. 

How does this benefit farmers and economy? 

Understanding how F. graminearum adapts and evolves in different hosts and environments is essential for developing effective disease management practices.  

“This research will provide new insights into the genetic diversity and adaptive strategies of the pathogen, leading to better disease forecasting and control methods,” Vaillancourt said. “Incorporating these findings into disease management models will enhance the prediction and mitigation of Fusarium head blight and Gibberella ear rot outbreaks, ultimately benefiting farmers and reducing economic losses.” 

The ultimate aim of this research is to identify genetic markers that can detect high-risk Fusarium strains. This will enable the development of advanced surveillance and prediction tools for growers, helping them manage disease epidemics more effectively. Improved pathogen monitoring will contribute to more sustainable agricultural practices and reduce the impact of these devastating diseases on global food security. 

Currently, the researchers are gathering isolates for genome sequencing and preparing for comprehensive analysis. The four-year project will progress through detailed genomic comparisons, field experiments and controlled crosses to achieve its objectives. 

"Our ultimate goal is to equip farmers with the knowledge and tools they need to effectively manage Fusarium graminearum,” Vaillancourt said. “By understanding the genetic and environmental factors that drive this pathogen's evolution, we can develop more precise and sustainable disease management practices, safeguarding both crop yields and food safety for future generations." 

Kiersten Wise, Mark Farman and Carl Bradley from the Department of Plant Pathology also took part in the study. 

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2024-67014-42427. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the Department of Agriculture.  

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