Etiological agents of Fusarium crown rot in Illinois wheat

Authors: LARABA, IMANE - Agriculture And Agri-Food Canada; Vaughan, Martha; McCormick, Susan; Busman, Mark; Cowger, Christina; OPPENHEIMER, PETER - North Carolina State University; Opoku, Joseph; Whitaker, Briana

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Fusarium crown rot (FCR) is a global disease of wheat and other cereal crops. FCR has caused wheat yield losses of 35% in the U.S. Pacific Northwest and up to 90% in Australia. Historically, FCR has been a contributor to yield losses in arid to semi-arid regions of the world. However, changing temperatures, precipitation, and crop management practices have increased the likelihood of FCR in new geographic regions, such the U.S. Midwest. In Illinois, winter wheat is the third largest crop, with approximately 700,000 acres harvested annually. Therefore, ARS researchers in Peoria, Illinois, and Raleigh, North Carolina, in collaboration with scientists from Agriculture and AgriFood Canada, looked for FCR in Illinois wheat fields and detected high FCR incidence in four of fifteen wheat fields surveyed in early summer 2022. Wheat crowns and heads were sampled, and genetic sequencing was used to identify the fungal pathogens causing FCR. The identification of fungi causing FCR disease in Illinois will serve as a resource for crop managers and breeders targeting effective control strategies in a changing agroecosystem.

Technical Abstract: The world is experiencing major changes in both climate and agronomic practices, that are intensifying the need to monitor plant diseases as they expand into new growing regions. Fusarium crown or foot rot is one disease of wheat and other cereals that has previously been the subject of economic concern and research primarily in arid to semi-arid regions of the world. Many of the etiological agents involved in Fusarium crown rot are cross-pathogenic in head tissues, causing the disease Fusarium head blight and increasing the risk for mycotoxin contamination of foods. During a coincident survey of Fusarium head blight in the midwestern U.S. state of Illinois in 2022, four soft red winter wheat fields displayed a high incidence of severe crown rot symptoms. The etiological agents of the observed symptoms were identified by translation elongation factor 1a sequencing, which revealed Fusarium graminearum, FSAMSC 3, and F. acuminatum as the primary agents of Fusarium crown rot in Illinois wheat. The dominant pathogen varied across fields and a high diversity of likely secondary colonizers was also noted across fields – with recovered isolates spanning five species complexes within the genus Fusarium. Lastly, no mycotoxins were detected in the screened wheat heads. Our results highlight the impact of local conditions in driving Fusarium crown rot disease and pathogen dynamics, even at relatively limited spatial segregation between fields. The identification of Fusarium crown rot agents in Illinois will serve as a resource for crop managers and breeders targeting effective control strategies in a changing agroecosystem.