Ontario Grain Farmer December 2021/January 2022

28 WHEN SOYBEANS ARE planted, most farmers, thoughts revolve around current weather patterns, upcoming herbicide applications, what the soybean market is doing, or a host of other pertinent considerations. But does the thought cross many farmers’ minds about the time and effort that has been invested into creating a good quality seed, which will in turn produce a high yielding soybean plant? Or have we just come to expect it? If we jump back to high school science class, many may be able to recall some of the learnings on genetics and cross breeding, others may remember their first pickup truck that they drove to those classes better. But no matter what is remembered, the general knowledge that was most likely retained was that good science doesn’t happen overnight. In fact, breeding a soybean seed from start to when it becomes commercially available can take anywhere from eight to 10 or more years. Breeding for any type of plant starts with crossing one with another. Dr. Milad Eskandari, an associate professor working on soybean breeding and genetics at the University of Guelph, Ridgetown Campus, used an example of breeding soybeans for soybean cyst nematode (SCN) resistance. It is all about taking one soybean plant that has high yields, crossing it with another one that shows SCN resistance, which might not have a high yield, and working your way through selecting the best offspring from the various crosses made that contains both best yield and SCN. Sounds easy? Think again. THE BREEDING PROCESS Eskandari begins by crossing the two chosen plants, this is called an F1 cross, in a greenhouse. This is done by taking the pollen and placing it on the stigma, it is a very tedious process requiring tweezers and a magnifying glass. Once the F1 crosses have produced a seed, they will then plant them in a field as F2 (the second generation of the particular cross), the field must have maximum segregation. The goal at this stage is to Seed development: soybeans THE PROCESS OF PRODUCING THE BEST VARIETY Laura Ferrier produce 500, F2 plants from 500 seeds from the F1 generation. The seeds from the F2 generation are sent to Costa Rica to be planted in the fall in a nursery. They will plant the 500 F2 seeds, allow them to mature and then pick one seed from each plant (now the F3 generation). Planting each seed, picking one seed from each plant (F4 generation) and send them back to Ontario. At this point Eskandari will receive 500 seeds back. The F4 generation of seeds will be planted in the spring in an Ontario field. At this point the first selection happens, there are 500 unique plants to look at, with about 120 plants that seed will be collected from. Selection is based on plants that look promising and that fall into the right maturity group. “Each of these single plants has the potential to go to the farmer eventually,” Eskandari notes. The seeds that made this first selection cut will then be planted again (F5 generation), with selection processes again looking at maturity, along with appearance, seed size, and lodging potential. At the F5 generation, if the breeder was, for example, aiming for an SCN resistant variety, Eskandari says, “that at the F5 stage they take leaf tissue and will do a genetic marker analysis. If the plant is showing resistance, it will be kept in the program, if not it will be discarded.” The aim at this point is to have up to 75 plants that are planted in the F6 generation, which is the preliminary yield trial stage. PRELIMINARY TRIALS At the preliminary yield trial stage, there are two trials with two replications at two locations. Again, the selection is done for ideal plants. “From this stage, the lines will be always compared with current successful commercial lines in Ontario to select the high yielding. We also evaluate the lines for important seed Research