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Ontario Grain Farmer Magazine

Integrating disease resistance into high-yielding soft red winter wheat germplasm

Principal Investigator: Michel McElroy

Research Institution: Centre for Grain Research (CEROM)

Timeline: April 2025 – March 2028   

Objectives:

  • Evaluate a new potential source of Fusarium head blight (FHB) resistance (AAC Harfang) and its suitability for integration into soft red winter wheat (SRW) germplasm.
  • Investigate the effectiveness of current molecular markers on integrating FHB resistance from AAC Harfang into soft red winter wheat material.

Impacts:

  • The development of new SRW varieties with improved FHB resistance would greatly improve the profitability of wheat production in the province – fungicide treatments currently cost $32/ac (including product and application), nearly 5% of the total cost of production. Increased genetic resistance would mean that applications could be limited only to seasons where the disease pressure is elevated, making a meaningful impact on crop profitability.
  • Genetic resistance to FHB also lessens the risks of damaging outbreaks when other management strategies fail. In 1996, an FHB epidemic across the province cost growers more than $120M in losses.
  • High-yielding FHB-resistant lines with acceptable SRW quality could be put directly into variety registration trials, ensuring that producers could have access to new genetics within a few years. According to the 2023 Ontario Cereal Crop Committee 2024 report, there are only 2 SRW varieties out of 17 on the market that are rated as ‘moderately resistant’ (MR) in major wheat production zones (I and II), while over a third (6/17) are rated as susceptible or higher.

Scientific Summary:

Fusarium head blight (FHB) remains the most significant disease facing wheat production in eastern Canada and, with increased heat and precipitation associated with climate change, it is likely to only get worse. In 2023, for example, excessive rain in late summer caused significant FHB infections in Quebec, resulting in a massive downgrading of spring wheat harvest. Soft red winter wheat cultivar development over the past decades has greatly improved the yield and end-use quality profile but has lagged on Fusarium resistance. The vast majority of varieties listed in the Ontario winter wheat performance trial are rated as moderately-susceptible to highly-susceptible, meaning that fungicide applications are necessary in the event of unfavorable conditions. These applications are expensive, and ineffective if not applied within the critical period. Genetic resistance is the first line of defense against FHB in wheat production, but Ontario producers have few variety choices for this crucial aspect of disease management strategy.

One difficulty in integrating FHB resistance into superior SRW germplasm is that it is often associated with traits that can be undesirable to producers, including plant height, maturity date, and susceptibility to rust diseases. Even when traits are not directly linked to resistance, certain germplasm do not have good combining ability in crosses, resulting in progeny lines that are deficient in yield, quality or agronomic traits. New sources of disease resistance must be considered carefully when integrating them into backgrounds that are distinct in adaptation and quality class. This project aims to assess the suitability of AAC Harfang, an FHB-resistant feed quality variety, as a source of resistance for SRW varieties, using UGRC Ring, a high-yielding, widely-adapted variety with good pastry quality, as a parent. With field screening in FHB nurseries, agronomic evaluations, and application of markers, we are confident that superior lines can be identified.

External Funding Partners:

Producteurs de Semences du Quebec

SeCan