Ontario Grain Farmer March 2024

13 ONTARIO GRAIN FARMER “Essentially, we are arming our varieties with more resistance genes through the use of molecular markers and increasing the efficiency of developing new cultivars, which means more new disease-resistant and high-yielding food-grade soybean varieties will become available to farmers,” says Rajcan. Since the breeding process takes eight years, varieties developed from the initial crosses made in 2021 are expected to come to market in 2029. This project was funded by Grain Farmers of Ontario and the Ontario Agri-Food Innovation Alliance, a collaboration between the government of Ontario and the University of Guelph. • BREEDING FOR SCN AND WHITE MOLD Soybean breeders are also working to advance disease management. Dr. Istvan Rajcan, professor and graduate coordinator at the University of Guelph, recently led a project to increase the efficiency of selection for SCN resistance and white mold resistance in the breeding program. High throughput marker-assisted selection (MAS) for resistance traits was used annually in F4 and F5 soybean breeding populations. This method of selecting disease-resistant genes is significantly more efficient than phenotypic selection based on characteristics such as visual agronomic performance, maturity, number of pods per plant and absence of disease, and lodging. “When we use molecular markers, we can select the plants that will carry the resistance genes at the DNA level and not waste time or resources on testing materials in the field that don’t carry the resistance, and we do not want as new varieties,” explains Rajcan. While the project concept is relatively simple, he says the funding enabled researchers to assess a greater number of populations than they would have otherwise been able to. Crosses were initially made between SCN-resistant or white mold-resistant parents and high-yielding, high-quality food-grade soybean parents. The University of Guelph uses a nursery in Costa Rica to advance breeding materials to produce F4 populations over the winter months. From selected F4 plants, F5 generations are grown as single rows for selection in Woodstock the following year. Selected F5 single rows are grown in future trials in Woodstock, Elora, and St. Marys as recombinant inbred lines and tested for yield and agronomic traits. In this project, the marker-assisted selection occurred at both the F4 and F5 stages of the program to increase the number of resistant progenies selected for agronomic performance. Option 1 Spraying drones Built for farmers. We support and service what we sell. Come visit us at the March Classic. Manufacturer-certified seller of www.AgDrone.ca - info@AgDrone.ca - 519-343-5454 This research project received funding from Grain Farmers of Ontario. MARCH 2024