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Adaption mechanisms associated with survival under low-temperature flooding and ice encasement in Ontario winter wheat (Triticum aestivum L.)

Principal Investigator: Eric Lyons

Research Institution: University of Guelph

Timeline: April 2021 – March 2024   


  • To determine the impact of low-temperature flooding and ice encasement (LTFIC) events on the survival and maintenance of cold hardiness in historical and modern Ontario winter wheat varieties of interest using data from existing winter wheat programs (e.g., Branson, 25R46, CM614, Priesley, Secord and a winter rye check (AC Hazlet).
    • To determine the causal factors associated with plant injury and death under LTFIC in Ontario winter wheat.
    • To correlate morphological and physiological traits (survival under ice encasement [LD50 – days required to kill 50% of plants]; low temperature [LT50 – temperature required to kill 50% of plants] tolerance) and biochemical mechanisms (total non-structural carbohydrates, fructans, reactive oxygen species) associated with superior survival under LTFIC for screening in a breeding program.
    • Determine the usefulness of chamber, field and hybrid screening systems for selecting genotypes with superior winter survival under ice encasement in field conditions. 
    • Evaluate varieties for traits associated with LTFIC survival to inform breeding programs.
  • To determine the impact of seeding date (cumulative growing degree days [GDD] before the first killing frost), growth stage and fertility (i.e., phosphorous) on the morphological, physiological and biochemical components of winter survival under LTFIC.
  • To develop a statistical model to predict winterkill events using historical environment data and new data from ground level sensors from locations across Ontario. The model will allow for an economic impact of past and potentially future winterkill events when using winter wheat in Ontario farming systems specific to the wheat growing regions within Ontario. The model will predict risk (economic cost) associated with late planting or reduced plant size because of fertility limitations to aid in better management decisions on the farm.


  • Understanding the physiological and biochemical mechanisms that confer greater survival under LTFIC will allow breeders to screen populations for traits associated with superior survival in the absence of severe winter environmental conditions, resulting in elite winter wheat varieties that are better adapted to  Ontario’s climate and preserve yield for Ontario farmers. Having superior varieties will allow a greater number of farms to adopt winter wheat in rotation, resulting in better sustainability of the farm.
  • The development of a new Ontario area map based on components of winterkill will allow for data-based recommendations for producers. The Ontario area map will also allow breeders to target components of winterkill (e.g., snow mould, frost heaving, ice encasement, etc.) for specific growing regions, therefore reducing risks associated with winterkill and creating more profitable farm systems.
  • The development of an Eastern Canada Winter Cereal Survival Model will allow farmers to monitor cumulative winterkill days, manage risk, and make informed management decisions earlier in the year with regard to the economic value of fall fertility to increase plant size and potential survival of winter wheat.
  • The economic impact of winterkill is difficult to determine due to confidentiality of data. This research will allow for the prediction of the economic impact of winterkill in winter wheat using historical climate data across the different regions of Ontario. The research could also increase the number of farmers benefitting from winter wheat in rotation by decreasing loss risk.

Scientific Summary:

The adaptive strategies of Ontario winter wheat cultivars to LTFIC events have not been specifically addressed by researchers in favour of selection for broad ‘winter survival’. Previous studies have suggested that exposure to LTIFIC conditions significantly reduce winter survival of winter wheat through direct kill or increasing the risk of winterkill by reducing hardiness prior to early spring thaw-refreeze events. Variation for survival under ice encasement has been noted in other winter wheat-growing regions ranging from 2 to 13 days depending on screening method and field versus chamber acclimation procedures. Variation for such traits in modern Ontario winter wheat is currently unknown. The cause of plant injury and death under these anaerobic conditions is also not well understood, limiting selection for improved varieties based on morphological and physiological traits. Historical lines may possess superior adaptive strategies that have been lost due to selective breeding in the absence of severe winter environmental stresses.

Initial studies will evaluate historical and modern Ontario winter wheat varieties for variation in survival under LTFIC. Field- and chamber-acclimated plants will be evaluated for survival under ice encasement and LD50, LT50 and biochemical traits associated with cold hardiness (including total non-structural carbohydrates, fructans, reactive oxygen species and abscisic acid accumulation). The effect of planting date, growth stage and fertility (e.g., phosphorous application) on these components of cold hardiness will also be evaluated on field and chamber acclimated plants. To confirm the effectiveness and accuracy of controlled environment screening procedures for breeding programs, historical environmental data (2009 to 2019) and novel data from field level sensors from across Ontario will be used to develop a statistical model to predict winterkill events (based on the Winter Cereal Survival Model for Western Canada).

External Funding Partners:

This project was funded in part by the Ontario Agri-Food Innovation Alliance, a collaboration between the government of Ontario and the University of Guelph.

University of Guelph