Grainswest - Winter 2024

Winter 2024 Grains West 42 FEATURE and doesn’t necessarily spread quickly. However, machinery contamination may be an issue, and disinfecting equipment is not an easy task as the spores are lightweight and can persist in hard-to- reach places. Common bunt spores can remain viable in the soil for up to three years. The most effective forms of control are certified seed, fungicide seed treatments, crop rotation and the selection of varieties with adequate genetic resistance, said Aboukhaddour. ONGOING BUNT RESEARCH At the Swift Current Research and Development Centre, Firdissa Bokore leads a team of research scientists in the development of common bunt resistance in CWRS wheat varieties. He stepped into the role following the retirement of longtime research scientist Ron Knox. Beginning in December 2020, the project entitled, “Marker assisted breeding for common bunt resistance in new wheat varieties adapted to the Canadian Prairies,” is slated to wrap by September 2025. Funding partners include Saskatchewan’s Agriculture Development Fund, Alberta Grains, the Western Grains Research Foundation and SaskWheat. Its primary goal is to boost bunt resistance by gene stacking in CWRS wheat. The project generates crosses of elite bunt-susceptible CWRS lines with bunt resistance sources for marker- assisted selection. Markers are useful indicators, often within the plant’s DNA, that indicate the presence of a specific gene. Beyond this, the researchers have applied breeder-friendly markers of bunt resistance in breeding lines to improve upon, or validate, future markers. These markers allow breeders to work faster and more efficiently because they indicate which varieties contain desirable genes. From there, they can simply crossbreed these with other promising varieties. Bokore said there are lots of high performing wheat varieties out there, but their genetic makeup may not be entirely known. He points to recent studies at Agriculture and Agri-Food Canada Swift Current that identified several common bunt resistance genes in cultivars Lilian, Carberry and AC Cadillac that could be pyramided into a single variety. Recently developed varieties such as AC Brandon—now the dominant CWRS variety—lack sufficient resistance to bunt. “We need molecular markers to pyramid the genes in our newly developed varieties or in our breeding program,” he said. The current project funds, for instance, facilitated the development of new DNA markers for 12 bunt resistance factors, or genes, identified in various chromosomal regions of adapted CWRS cultivars. By understanding where molecular markers are located and what traits they are associated with, breeders can better track the genes and build upon these traits by stacking additional positive traits on top of them. The markers flag the genes and make the work of scientists that much easier and will produce higher performing varieties. “We use those markers to test thousands of breeding lines, and we don’t need phenotyping or field analysis to do that,” he said. “It just reduces the cost of field evaluation as lines carrying susceptible genes are discarded.” Newly developed markers are tested and verified in National Research Council labs. The markers developed by Bokore and his team will be additionally used in marker-assisted selection by the Swift Current wheat breeding program. His lines are also sent to New Zealand to multiply early generation seed to accelerate the work. “Breeding is a long process. We are not expecting varieties registered right away after this,” he said. “We are just getting elite lines that can go into testing for registration.” Through Bokore’s research and end goals, there is reason to believe future generations of spring wheat will only get better. This is good news for Canadian farmers who continue to grow a majority of CWRS in their fields. Bunt infection does not become evident until the head of the plant forms. The bunt ball in the infected head is exposed when crushed.