Research Highlights

Research Highlights
Soybean Breeding Program Solving Key Challenges for the Southeast

In this article, you’ll find details on:

  • The soybean breeding program at the University of Georgia is releasing high-yielding cultivars that fit key opportunities and address major challenges for Southeastern soybean farmers.
  • The program is developing soybeans with high oleic oil content, high yield and protein content, strong disease defense, the latest herbicide tolerance traits, insect tolerance, nematode resistance and more. 
  • It is currently the only U.S. breeding program, including private programs, focused on Maturity Groups 6, 7 and 8.

The University of Georgia soybean breeding programs includes these trials in Tifton, Georgia. The program develops soybeans with high oleic oil content, the latest herbicide-tolerance traits insect tolerance, nematode resistance and more. Photo: Zenglu Li

By Laura Temple

Selecting soybean varieties raises tough questions. 

  • Will a high oleic/low linoleic oil soybean yield as well as other varieties? 
  • Which is more important: yield or protein content? 
  • What about weed, insect, disease and nematode management?
  • Will varieties tolerate drought conditions?

The University of Georgia’s soybean breeding program helps farmers in the Southeast answer these questions by consistently releasing new, high-yielding cultivars in Maturity Groups 6, 7 and 8.

“Major seed companies don’t have soybean breeding programs in the Southeast anymore,” says Zenglu Li, Georgia seed development professor of soybean breeding and genetics at the University of Georgia. “We release cultivars and license our findings to companies to benefit the farmers.”

Because the program meets specific farmer needs, Li appreciates the long-term support provided by the Georgia Soybean Commodity Commission and the United Soybean Board. 

“We address big issues for farmers in this region,” he adds. “We ensure they can access high-yielding, profitable soybean varieties that target key issues.”

The program offers a strong pipeline of varieties with competitive yields, appropriate defensive packages and value-added traits. Plus, Li and his team are developing soybeans that allow Southeastern soybean farmers to take advantage of opportunities to improve profitability and solve common production challenges.

Building on SOYLEIC Success

Farmers in parts of the Southeast can earn a premium with soybeans that have a high oleic/low linoleic oil profile. Li and his team released three MG 6 and 7 cultivars with the SOYLEIC trait developed by the University of Missouri soybean breeding program. 

The UGA cultivars have been licensed to seed companies to give regional farmers access to high oleic/low linoleic soybeans. Additionally, they carry defensive packages needed in the hot, humid Southeastern climate to manage against soybean cyst nematode, root-knot nematode, frogeye leaf spot, stem canker and more.

“These cultivars deliver yields equal to or above the commercial standard,” Li says. “Farmers have been very happy with the performance of these soybeans, and we will have more SOYLEIC releases coming.”

Improving Protein Content 

For decades, soybean breeders have observed that selecting soybeans for high yield leads to lower protein content. Li and his team tackled the need for higher protein content without sacrificing yield in a project funded by the national soy checkoff.

“We developed lines that produce protein content 3% higher than commercial varieties, with competitive yields,” Li reports. “We are releasing one cultivar this year, with another in testing for one more year.”

UGA plans to share this breakthrough with other public breeding programs in other regions, and it can be licensed to commercial companies, as well. He believes it will benefit the poultry and livestock sectors, as well as other soybean industry stakeholders.

University of Georgia soybean breeding trials in Athens, Georgia, contribute cultivars that allow Southeastern soybean farmers to take advantage of opportunities to improve profitability and solve common production problems in the region.

Expanding Weed Control Technology

Li says that weed control is one of the biggest issues Southeastern farmers face. Herbicide-resistant weeds steal yield and require complex herbicide programs.

“The University of Georgia works with major companies like Bayer and Corteva,” he explains. “We have licensed the latest herbicide-tolerance technologies, including XtendFlex and Enlist E3. We have incorporated these valuable weed control traits into our elite germplasm.”

The UGA soybean breeding program incorporates these traits into later maturity groups that fall outside the companies’ focus. As the team develops cultivars with specific traits, they create both herbicide-tolerant and conventional versions. This strong pipeline of both types of soybean varieties gives regional seed companies and farmers access to the tools and options they need to manage weeds in soybean production.

Biting into Insect Management

Based on the previous discovery of the genes underlying insect resistance in soybean, Li’s UGA breeding team tried to incorporate this native trait into elite soybean germplasm. The trait provides resistance to the defoliating pests, including caterpillar species. 

Insects like soybean looper, armyworm, velvetbean caterpillar and others commonly cause yield loss in Southeastern soybeans. Many years, farmers make multiple insecticide applications to protect their soybeans.

“We have developed a cultivar with tolerance to insect feeding and excellent yield,” Li says. “It recently ranked No. 1 in yield in both USDA’s Uniform Soybean Tests and Georgia’s state variety trials.”

The trait naturally exists in the soybean genome, making it available in both conventional and genetically modified soybean varieties.

The soybean breeding program at the University of Georgia, which includes these trials in Tifton, Georgia, is releasing high-yielding cultivars that fit key opportunities and address major challenges for Southeastern soybean farmers.

Collaborating to Boost Nematode Resistance

Because soybean cyst nematode persists in soybean fields throughout the U.S., Li and his team work closely with breeders and researchers in Minnesota, Iowa and Missouri to strengthen nematode resistance options across maturity groups. In addition, his team combines SCN progress made in other regions with genetics providing resistance to root-knot nematode, found primarily in the South.

“We’ve made great progress by working together,” he reports. “Cooperation speeds gene discovery work for new sources of SCN resistance. For example, we are currently working to validate a gene we found that appears to provide a new type of SCN resistance.”

Public breeding programs share these discoveries and license proven germplasm to seed companies to help farmers manage SCN. At the same time, his program focuses on developing a strong pipeline of late maturity group cultivars with proven SCN and root-knot nematode resistance. 

Tackling Drought Tolerance

Li says drought stress is a big issue in the region, especially because most farmers are reluctant to spend money on irrigation for soybeans. 

“It’s difficult to quantify drought tolerance,” he continues. “As part of a national team, our team is exploring slow canopy wilting, a characteristic that helps soybeans conserve moisture.”

They test lines under rainfed conditions and a rainout shelter to identify those with strong performance. New technology helps the team phenotype the lines for this characteristic and look for new genes that support soybean performance under limited moisture.

Putting It Together

Though Li’s team is developing MG 6, 7 and 8 cultivars that address many challenges, they integrate multiple characteristics before releasing new cultivars. For example, the SOYLEIC varieties carry disease and nematode resistance. And they develop many cultivars with and without specific weed tolerance technology.

“Because so many things are essential to soybean production, we take a very comprehensive approach to develop soybean cultivars,” he says. “The genomic tools, like marker-assisted selection and genomic prediction and selection, including some that we have developed over time, make it very efficient to select and confirm that the traits we desire are present in a cultivar. We also aim to accelerate the breeding cycle by using these genomic tools so farmers can benefit from this work.”

Additional Resources

Published: May 20, 2024

The materials on SRIN were funded with checkoff dollars from United Soybean Board and the North Central Soybean Research Program. To find checkoff funded research related to this research highlight or to see other checkoff research projects, please visit the National Soybean Checkoff Research Database.