For thousands of years, agriculturalists have selected plants with desirable traits and bred them to create better plants, or cultivars. Today, soybean researchers continue to do the same, as farmers look for soybeans to plant that have better yields, decreased lodging and resistance to drought, disease and pests.
Have you ever wondered how soybean cultivars are developed? What process do researchers go through to improve soybeans with high-quality cultivar traits? William J. Kenworthy, Ph.D., University of Maryland emeritus professor, outlined the process and length of time necessary for a breeding program in the Plant Management Network’s most recent “Focus on Soybean” webcast. The soy checkoff sponsors these webcasts through a partnership with the Plant Management Network, and all U.S. soybean farmers have access to them for free.
Step 1: Planned Cross and Hybridization
This process usually takes about one year. The objective involves hand crossing two parent plants in an attempt to combine the best genes or traits from each parent in the progeny generated.
Step 2: Generation Advance and Line Selection
This two-to-three-year process involves growing and evaluating plants for two or three generations, searching for individuals with the desired traits. At the conclusion of this step, progeny derived from each individual selected plant are called breeding lines and should be uniform in appearance and include the desired traits. Greenhouse and winter nursery facilities can be used to complete multiple generations each year.
Step 3: Yield Testing
For the next three to five years, breeding lines are tested for yield. Researchers plant replicated plots at multiple locations and continue to re-test the highest-yielding breeding lines to identify those with the best performance across states and regions. The top performing lines become candidates for release as new cultivars.
Step 4: Purification and Seed Increase
The final step in cultivar development can take two or more years. This step prepares the new cultivar for marketing to farmers. A sample of seeds of the new cultivar is grown and individual plants are evaluated for uniformity in appearance and reaction to pests and other traits. Although there are at least two methods that can be used to complete this step, the goal is to produce an initial increase of genetically pure seeds of the new cultivar. This initial increase of seed is called breeder seed and it can be a few pounds or a few bushels in size. Careful seed production and processing steps are followed to prevent seed mixtures or contamination. Thousands of bushels of seed are needed to meet the demand for a new cultivar.
Source: Unitedsoybean.org