Updated January 27, 2026:
This project focused on developing, evaluating, and advancing high-yielding soybean germplasm with improved climate resilience and expanded genetic diversity across maturity groups (MG) 00 through VIII. Increasing climate variability—characterized by more frequent drought, heat stress, flooding events, and erratic precipitation—poses significant challenges to soybean production across U.S. growing regions. The overarching goal of this work was to reduce production risk for soybean growers by delivering varieties and breeding lines that combine high yield potential with stable performance under diverse and stressful environmental conditions, while simultaneously strengthening the genetic base available to public breeding programs.
During the reporting period, the project made substantial progress toward all major objectives through a coordinated, multi-state, public breeding network involving Virginia Tech, the University of Missouri, the University of Georgia, the University of Arkansas, North Dakota State University, and USDA-ARS partners. This collaborative framework enabled large-scale multi-environment testing, integration of advanced phenotyping and genomics tools, and accelerated advancement of elite materials toward release.
Advancement and evaluation of high-yielding, climate-resilient varieties:
Across multiple maturity groups, advanced breeding lines and released cultivars demonstrated excellent yield performance relative to commercial checks in official regional and national trials. In the USDA Uniform Trial for early MG IV, one advanced line evaluated by Virginia Tech ranked first overall, producing 65.0 bu/ac and outperforming all commercial checks. This line also carries resistance to soybean cyst nematode (SCN), southern root-knot nematode, and stem canker, highlighting the project’s emphasis on combining yield with durable resistance traits.
In MG V, several released and near-release lines ranked among the top entries in the USDA Uniform Trials, with yields ranging from approximately 64.6 to 65.0 bu/ac and strong performance across multiple environments. Preliminary Uniform Trials further identified multiple early and late MG V lines that met or exceeded check performance, confirming their competitiveness and supporting continued advancement toward release.
Partner programs contributed significant progress by advancing large numbers of elite lines into broader testing networks. One program advanced 14 lines into the USDA Uniform Test and submitted 22 additional lines into the USDA Preliminary Uniform Test across MG III–IV. These entries were selected based on combinations of high yield, disease resistance, and tolerance to abiotic stresses such as flooding. Reported yields across environments ranged from approximately 58.7 to 79.6 bu/ac, demonstrating strong adaptation potential across diverse production systems.
Documented yield stability under environmental stress:
A major accomplishment of this project was the documentation of yield stability under drought stress in official variety testing. In the South Carolina Official Variety Trials, one breeding line proposed for release exhibited exceptional performance at a location experiencing severe drought. While drought reduced the test mean yield by more than 19 bu/ac when comparing irrigated to dryland conditions, this line maintained nearly identical yields under both systems, differing by only 0.4 bu/ac. This level of stability, while competing directly with commercial cultivars, underscores the project’s success in identifying materials capable of buffering yield losses under stress.
Large-scale field testing and pipeline advancement:
The breeding pipeline was strengthened through extensive field evaluation and selection. One collaborating program evaluated 25 advanced lines across 30–34 locations spanning multiple trial networks, including USDA Uniform Tests and Official Variety Trials. Based on performance, the most promising lines were advanced for continued testing and seed increase. In parallel, early-generation testing remained robust, with more than 15,000 progeny rows grown and over 1,600 lines selected for multi-location preliminary testing, ensuring a broad and well-screened base for future cultivar releases.
Expansion of genetic diversity for climate resilience:
To enhance long-term resilience, the project continued integrating diverse genetic backgrounds into breeding programs. Crosses involving plant introductions and lines containing Glycine soja ancestry were developed to introduce novel alleles associated with stress tolerance. In one example, a line containing exotic pedigree contributions performed on par with elite commercial checks in preliminary trials, demonstrating that increased diversity can be incorporated without sacrificing agronomic performance.
A comprehensive genetic diversity analysis was conducted using more than 8,000 accessions from the USDA Soybean Germplasm Collection alongside over 2,500 breeding lines. Principal component analysis identified seven major genetic clusters, and a core set of 220 highly diverse accessions was selected to maximize genetic breadth. These accessions span multiple maturity groups and geographic origins and will serve as a valuable resource for future breeding and evaluation.
Use of modern phenotyping and genomics tools:
The project leveraged emerging technologies to accelerate selection and improve understanding of stress responses. Drone-based thermal imaging was deployed on a diverse panel of soybean accessions at multiple growth stages to measure canopy temperature, a proxy for heat and water stress response. Calibrated thermal data revealed substantial genetic variation and supported genome-wide association analyses that identified key loci associated with canopy temperature at reproductive stages.
Genomics-enabled selection also expanded significantly. Thousands of advanced lines were genotyped using high-density SNP markers, and datasets were integrated into genomic prediction models now encompassing more than 2,000 lines. These models are actively guiding parent selection, cross design, and early-generation advancement decisions. Multi-program population structure analyses further documented how breeding has shifted allele frequencies over time, providing insight for optimizing future selection strategies.
Overall progress:
Collectively, these activities represent strong progress toward developing and delivering soybean germplasm that is high-yielding, genetically diverse, and resilient to climate stress. The coordinated testing, integration of modern tools, and advancement of elite materials position this project to deliver meaningful benefits to soybean producers and the broader industry.
Objective 1. Evaluate and release high-yielding soybean varieties with regional adaptation and climate resilience across maturity groups 00 to VIII
Under Objective 1, this project achieved major outcomes in the evaluation, advancement, and release of soybean cultivars and elite breeding lines that combine high yield potential with enhanced stability under variable and stress-prone environmental conditions. Through coordinated testing across multiple public breeding programs and regions, the project generated robust, multi-year evidence supporting the release and continued advancement of climate-resilient soybean germplasm across a broad range of maturity groups.
In early maturity groups, advanced lines evaluated in USDA Uniform Trials demonstrated exceptional yield performance relative to commercial standards. In early MG IV, one advanced line evaluated through the Virginia Tech breeding program ranked first overall in the USDA Uniform Trial, producing 65.0 bu/ac and outperforming all commercial check varieties. Importantly, this performance was achieved across multiple environments, indicating broad adaptation rather than location-specific success. Beyond yield, this line carries resistance to soybean cyst nematode (SCN), southern root-knot nematode, and stem canker—traits that directly contribute to yield protection under stress conditions. The combination of high yield and multi-disease resistance illustrates the project’s success in aligning productivity with resilience, a key requirement for modern soybean production systems.
In MG V, the project delivered multiple strong outcomes through the evaluation of both released and near-release cultivars. Two released varieties consistently ranked among the top four entries in the 2025 USDA Uniform Trial, with yields approaching or exceeding 65 bu/ac. These cultivars exhibited strong performance across diverse environments, confirming their regional adaptability and reliability. A near-release conventional line ranked third overall while also demonstrating resistance to SCN and stem canker. These results provide clear evidence that breeding strategies emphasizing yield stability, disease resistance, and adaptability are effective in generating competitive cultivars for mid-southern production regions.
Preliminary Uniform Trials played a critical role in strengthening the advancement pipeline. Multiple early- and late-MG V lines identified through preliminary testing met or exceeded commercial check yields, confirming their potential for advancement into Uniform Trials. These results ensure continuity in cultivar development and maintain a strong pipeline of elite material capable of meeting future producer needs.
Partner breeding programs made substantial contributions to Objective 1. One program advanced 14 elite soybean lines into the USDA Uniform Test and submitted 22 additional lines into the USDA Preliminary Uniform Test across MG III–IV. These lines were selected through rigorous multi-year evaluation based on yield performance, resistance to multiple diseases, and tolerance to abiotic stresses such as flooding. Yield performance across environments ranged from approximately 58.7 to 79.6 bu/ac, reflecting both genetic diversity and adaptability. Several entries exceeded 100% of the test mean, reinforcing their competitiveness and justifying continued evaluation for potential release.
In the southern region, a high-yielding XtendFlex® cultivar in MG VII completed the release approval process following outstanding performance in both USDA Southern Uniform Tests and state variety trials. Across seven Uniform Test environments, this line exceeded the check mean by more than 6%. In nine state variety test environments, including both full-season and late-planted locations, it ranked first overall and outperformed commercial XtendFlex® checks by approximately 8–9%. In addition to its yield advantage, the cultivar possesses resistance to SCN, southern and Javanese root-knot nematodes, stem canker, and moderate resistance to frogeye leaf spot. The release of this cultivar provides soybean producers with a resilient, high-yielding option that also offers enhanced weed management flexibility through advanced herbicide tolerance technology.
In Arkansas, a conventional MG 4.5 soybean cultivar with documented early-season flood tolerance was publicly released. Across 75 environments evaluated from 2020 to 2025, this cultivar consistently matched or exceeded commercial checks. Its performance under flooding conditions was particularly notable, with substantial relative yield advantages observed in early-season flood trials. These results address a critical production challenge in regions prone to excessive rainfall and early-season flooding. Conversion of this cultivar into Enlist-E3® and XtendFlex® genetic backgrounds is underway, ensuring its continued relevance as weed management technologies evolve.
Collectively, results from Objective 1 demonstrate that the project successfully delivered both immediate cultivar releases and a strong pipeline of elite breeding lines. These outcomes provide soybean producers with improved options for managing climate risk while sustaining high yield potential across diverse production environments.
Objective 2. Develop soybean germplasm with diverse genetic backgrounds to strengthen climate resilience
Objective 2 focused on expanding the genetic diversity used in soybean breeding to enhance long-term resilience to climate variability while maintaining elite agronomic performance. The results demonstrate that strategic incorporation of diverse germplasm can contribute directly to improved stress tolerance and yield stability without compromising productivity.
Across participating programs, targeted crosses were developed using plant introductions, drought-tolerant accessions, and lines containing wild soybean ancestry. At Virginia Tech, breeding populations were created using plant introductions and an elite line containing Glycine soja ancestry. One resulting line with exotic pedigree contributions performed on par with elite commercial checks in preliminary yield trials, confirming that novel genetic diversity can be incorporated into elite backgrounds while maintaining competitive yield.
The University of Missouri developed new populations by crossing drought- and heat-tolerant donor parents with elite, flood-tolerant lines. These populations are progressing through progeny rows and represent valuable reservoirs of stress tolerance traits for future cultivar development. The structured advancement of these populations ensures that useful alleles are retained while unfavorable traits are progressively eliminated through selection.
At the University of Georgia, a drought-tolerant plant introduction was identified and used to develop a recombinant inbred population. Under rain-fed conditions, several derived lines outperformed the elite parent by 5–15%, demonstrating the potential of diverse germplasm to enhance performance under water-limited environments. These results reinforce the importance of evaluating diverse materials under realistic stress conditions rather than solely under optimal management.
A major outcome under Objective 2 was the comprehensive genetic diversity analysis conducted using more than 8,400 accessions from the USDA Soybean Germplasm Collection alongside over 2,500 breeding lines. Principal component analysis identified seven major genetic clusters and highlighted the genetic distance between elite breeding material and underutilized germplasm. Using this information, a core collection of 220 highly diverse accessions was selected to maximize genetic diversity relative to elite breeding lines. This curated set spans multiple maturity groups and geographic origins and represents a strategic investment in the future adaptability of soybean breeding programs.
These accessions will be evaluated using high-throughput phenotyping tools, including drone-based imaging, to efficiently identify promising candidates for advancement. Outstanding accessions will be incorporated into future crossing blocks, ensuring that breeding programs continue to access novel alleles as climate challenges intensify.
Overall, Objective 2 strengthened the genetic foundation of soybean breeding programs and reduced long-term vulnerability to climate stress by expanding the pool of useful alleles available for selection.
Objective 3. Discover novel genes and traits associated with climate resilience using emerging technologies to support breeding efforts
Objective 3 generated new physiological, genetic, and analytical insights that directly support the development of climate-resilient soybean cultivars. Emerging technologies were integrated into breeding workflows to improve selection accuracy, efficiency, and understanding of stress responses.
High-throughput phenotyping using drone-based thermal imaging was deployed on a diverse soybean panel at multiple growth stages. Canopy temperature measurements revealed substantial genetic variation and clear differences among growth stages, reflecting the dynamic nature of stress responses throughout development. Genome-wide association analyses identified significant loci associated with canopy temperature at key reproductive stages. Some loci were consistently detected across stages, while others were stage-specific, indicating both stable and developmentally regulated genetic control of stress responses.
Physiological evaluations conducted by USDA-ARS partners provided complementary insights into drought tolerance mechanisms. Drought-tolerant lines exhibited improved regulation of stomatal conductance and lower leaf vapor pressure deficit compared with sensitive cultivars, indicating more efficient water use and reduced heat load under stress. These physiological traits translated directly into agronomic performance. One breeding line proposed for release demonstrated exceptional yield stability under drought conditions in official variety testing, maintaining nearly identical yields under irrigated and dryland conditions while commercial checks experienced substantial yield losses.
Additional genome-wide association studies targeting photosynthesis-related traits identified multiple genomic regions controlling photosynthetic efficiency and non-photochemical quenching. These findings confirm the polygenic nature of climate resilience and underscore the importance of genomic prediction approaches that capture small-effect loci distributed across the genome.
Genomic prediction models were further refined and implemented across partner programs. More than 2,000 lines with integrated genotype and multi-environment phenotype data are now included in training populations. These models are actively used to prioritize parents, optimize crossing designs, and select superior progeny at early generations, reducing time and cost while increasing selection accuracy.
Population structure analyses across hundreds of elite lines from multiple breeding programs documented shifts in allele frequencies resulting from decades of selection. These insights are being used to refine prediction models and guide future breeding strategies, ensuring continued genetic gain under changing environmental conditions.
Overall Impact and Significance
Taken together, results from all three objectives demonstrate that this project delivered meaningful, measurable advances in soybean breeding for climate resilience. High-yielding cultivars were released or advanced toward release; breeding pipelines were strengthened with diverse and well-characterized germplasm; and modern phenotyping and genomics tools were fully integrated into routine breeding operations.
These outcomes reduce production risk for soybean growers by providing cultivars with improved yield stability under drought, flooding, and variable conditions. At the same time, they enhance the efficiency and long-term sustainability of public breeding programs. The framework established through this project provides a scalable model for continued genetic improvement as climate challenges intensify.