Research Highlights

SOYGEN2 Project Identifies Opportunities for Genetic Gain

By Barb Baylor Anderson

Genetic variation in natural populations is the basis for resilience and survival. Plants undergo natural selection in response to their environment. It also is the foundation for long-term success in soybean breeding populations, and researchers are exploiting opportunities with genetic variation through the SOYGEN (Science Optimized Yield Gains across Environments) Project. 

“SOYGEN leverages and builds upon ongoing and previously funded research to increase soybean genetic gain for yield and other targeted traits in the north central U.S. The work will result in improved soybean cultivars with higher yields and higher quality,” says George Graef, University of Nebraska professor and principal investigator for the North Central Soybean Research Program (NCSRP) project funded through the soybean checkoff.

Graef’s work is one of four major objectives that exist within the SOYGEN2 project, focused on creating more effective characterization and use of the USDA Soybean Germplasm Collection.

“There are about 20,000 unique accessions in the collection. The foundation of the current U.S. commercial soybean germplasm pool is built on less than 20 of those,” he says. “Over the past 60 years, many accessions have been identified and used to contribute specific resistance genes for diseases like phytophthora root rot and soybean cyst nematode. Those resistance assays are conducted using the pathogen or insect in controlled environments void of yield measurements.” 

However, Graef explains that no real effort has been made to more effectively use the vast genetic resources for improvement of more complex, quantitative traits like yield. Until now.

“Our project is made possible in large part by the genotype information that is available on virtually every accession in the collection. We used the existing genotype (DNA) information to select 500 accessions that we showed represent the total genetic variation present in the collection in Maturity Groups I-IV,” he says. “We evaluated those 500 lines in multiple environments across the north central region over two years to get high-quality data on yield, seed composition and other agronomic traits.” 

With yield and agronomic traits (phenotype) data in hand, researchers were able to then combine all of the details and go back to the collection’s remaining untested accessions and predict yield and other agronomic traits based on their genotype information. By evaluating 500 accessions, Graef says they basically received reliable information for the whole collection. 

Researchers spent another two years verifying accuracy of the predictions by resampling new accessions and again evaluating yield and other agronomic traits. Graef says already some of those results show soybean breeders can make more informed decisions for selecting accessions more likely to produce progenies with superior yield and seed quality traits. 

“We’ve also evaluated other kinds of traits that could have some effect on yield, like plant growth and development and canopy coverage,” he says. “Breeders can use the high-quality data on now 750 accessions that did not exist previously. Some of them may be good choices for parents in a breeding program. In addition, predictions on the rest of the accessions can be used to select accessions that have the highest predicted breeding values based on our analyses.” 

Graef says extensive information on multiple genotypes in multiple environments will become available, so researchers can look more closely at genotype–environment interactions for yield and other traits to help better understand them, be able to model them and perhaps even make decisions for either targeting specific genotypes for certain types of environments or identifying genotypes that are more stable across a wider range of environments. Breeding programs in both the public sector and industry will be able to use the information to advance their work. 

“Successful public breeding programs start with great information. Projects funded through the NCSRP are a great way to share success between breeding programs. Strong public varieties are quite popular in my home state and are essential in providing competition to the commercial seed companies and keeping their prices in line,” says Mike Langseth, soybean farmer from Barney, N.D. and North Dakota Soybean Council secretary.

“Yield and quality are important for genetic gain, but so is genetic diversity,” says Graef. “The genetic diversity present at the beginning limits genetic diversity and progress in the long run. So being able to make more informed decisions on what accessions will be best to enhance genetic diversity of the U.S. soybean germplasm pool and contribute to greater yield and quality will create a strong foundation for the future long-term success of the U.S. soybean industry.” 

Published: May 10, 2021