GrainsWest Spring 2021

Spring 2021 Grains West 48 Researchers produce positive cereal crop characteristics Geneticadvancesmultiply GRAIN SCIENCE NEWS TWO RESEARCH PROJECTS FUNDED by the Alberta Wheat Commission (AWC) have made significant advances in cereal crop genetics. Overseen by Pierre Hucl of the Crop Development Centre (CDC) at the University of Saskatch- ewan, the first of these examined the viability of a new dwarfing gene in bread wheat. Secondly, Nora Foroud of Agri- culture and Agri-Food Canada (AAFC) developed new wheat and barley lines with improved resistance to Fusarium head blight (FHB). HOW DOES SHORTER WHEAT MEASURE UP? Hucl’s project focused on a dwarfing gene that was discovered as a mutation in U.S.- grown durum wheat in the late 1980s. Hucl took this gene, Rht18 , and crossed it into CDC Utmost, a CWRS variety. This was the first introduction of this gene into a Canadian bread wheat variety. “We developed lines that carried the gene and others that did not in a CDC Utmost background,” said Hucl. Known as near-isogenic lines, these two iter- ations of CDC Utmost carry the same genetic material with the exception of the introduced dwarfing gene. “Then you can really tease out what the effects of the gene are. Does this gene have an effect other than just reducing plant height?” said Hucl. The near-isogenic lines first hit the field in 2016 as part of a graduate project conducted by Hucl’s student Sara Tetland. AWC contributed $61,000 to the project, which concluded in 2019. The Saskatche- wan Agriculture Development Fund and SaskWheat also funded the research. The lines with Rht18 were, on average, 15 centimetres shorter than the control lines. This produced a higher harvest index, determined by dividing the dry grain yield of a plant by the amount of its above-ground dry plant material. In two plants with identical grain yield, the one with less above ground plant material would display a higher harvest index. “The [harvest index] is important because plants use the products of pho- tosynthesis for either growth or repro- duction,” said AWC research program manager David Simbo. “If a plant is en- gineered to grow short, a larger portion of the products of photosynthesis will be used in reproductive growth, which is grain yield.” While shorter stature can improve wheat harvestability, Hucl’s research un- covered a downside to the petite plants. Photo:CourtesyofSaraTetland The ones carrying the dwarfing gene had 36 per cent higher FHB infection levels and DON levels increased by 16 per cent within inoculated nurseries. Hucl believes the increased disease prevalence is a result of the heads being closer to the ground where rain can more easi- ly splash inoculum from crop residue onto the flowering plant. Because the shorter plants lack the physical escape mechanism of height, Rht18 will be best deployed in crosses with lines that have strong genetic resistance to Fusarium , unlike CDC Utmost, which is moderately susceptible. The project also included quality test- ing that is standard on all CWRS lines. Researcher Pierre Hucl introduced a dwarfing gene into CDC Utmost, a CWRS variety, pictured on the left next to the non-dwarf version.