Wild soybean (Glycine soja Siebold & Zucc.) has valuable genetic diversity for improved disease resistance, stress tolerance, seed protein content and seed sulfur-containing amino acid concentrations. Many studies have reported loci controlling seed composition traits based on cultivated soybean populations, but wild soybean has been largely overlooked. In this study, a nested association mapping (NAM) population consisting of 10 families and 1107 recombinant inbred lines was developed by crossing 10 wild accessions with the common cultivar NC-Raleigh. Seed composition of the F6 generation grown at two locations was phenotyped, and genetic markers were identified for each line. The average number of recombination events in the wild soybean-derived population was significantly higher than that in the cultivated soybean-derived population, which resulted in a higher resolution for QTL mapping. Segregation bias in almost all NAM families was significantly biased toward the alleles of the wild soybean parent. Through single-family linkage mapping and association analysis of the entire NAM population, new QTLs with positive allele effects were identified from wild parents, including 5, 6, 18, 9, 16, 17 and 20 for protein content, oil content, total protein and oil content, methionine content, cysteine content, lysine content and threonine content, respectively. Candidate genes associated with these traits were identified based on gene annotations and gene expression levels in different tissues. This is the first study to reveal the genetic characteristics of wild soybean-derived populations, landscapes and the extent of effects of QTLs and candidate genes controlling traits from different wild soybean parents.

Edamame is a vegetable soybean (Glycine max) that is harvested at the R6 growth stage. Although it is relatively new to America, the acreage and market demand of edamame have steadily increased. Developing new cultivars that are more adapted to local environments and crop management systems is significantly important to promoting specialty crop production and meeting the market requirements. In this study, 10 edamame breeding lines and four check cultivars were evaluated during 2020–23 to determine the potential production in the southeastern United States. Among genotypes, there were significant differences in the fresh pod and mature seed yields and agronomic and seed composition traits that were investigated. The year effects and genotype × year interactions were also significant in most cases. Fresh pod and mature seed yields were not significantly correlated with most of other agronomic traits and seed compositions. Over 4 years, the fresh pod yield averaged 11,227.5 kg·ha−1 (range, 9800.1–13,154.3 kg·ha−1), and the mature seed yield averaged 2814.7 kg·ha−1 (range, 2029.2–3175.2 kg·ha−1). The average 100-seed weight of 14 genotypes was 26.9 g (range, 23.1–30.1 g), and the average seed size of nine breeding lines was larger than that of the check. Maturity occurred on average 153.3 days after planting (range, 147.1–159.5 days). Based on dry weight, seed protein, oil, and sucrose contents had averages of 43.5%, 18.7%, and 5.0%, respectively. The estimates of broad-sense heritability were medium to high (66.82%–94.90%) for most of the traits, whereas the heritability estimates for fresh pod yield and duration from flowering to maturity were relatively low (23.44%–42.29%). Several breeding lines exhibited good yield, larger seed size, and higher contents of protein, oil, and oleic acid, suggesting the potential of release and commercial production.

In soybean [Glycine max (L.) Merr.], drought stress is the leading cause of yield loss from abiotic stress in rain-fed US growing areas. Only 10

The narrow genetic base of the US soybean (Glycine max [L.] Merr.) crop makes it vulnerable to emerging abiotic and biotic stress challenges, and limits resiliency of the soybean crop to meet changes in consumer demand for improved seed composition and agronomic performance. The United States Department of Agriculture Glycine soja (Siebold & Zucc.) germplasm collection provides a valuable genetic resource to meet these challenges. Glycine soja is more genetically diverse than domesticated soybean. Even though wild soybean hybridizes freely with G. max, breeding efforts with wild soybean have not been widely employed because the interspecific progeny inherits undesirable traits from the wild parent. Particularly, these progenies inherit a vine-like architecture that prevents machine harvest. We assessed the potential for improving recovery of agronomically valuable progeny from interspecific crosses in three experiments using 11 interspecific populations. We found that optimal choice of either parent could triple the frequency of recovery of desirable progeny. Selection for large F-3 seed size was positively correlated with upright growth habit/plant architecture in five of 11 populations and could triple the recovery of desirable plants. Marker analysis of parents and progeny indicated selection for larger seed size caused minimal selection against the genome of the wild parent. Most genetic markers specific to a wild parent could be recovered in the aggregate of 8-10 upright interspecific progenies, identified via post selection marker analysis. We concluded that choice of parent and selection for larger seed can maximize recovery of the wild genome in machine harvestable progenies.

USDA-N5001 (Reg. no. GP-524, PI 702592) is a conventional early maturity group (MG) V soybean [Glycine max (L.) Merr.] germplasm with high yield potential and elevated seed and meal protein contents. USDA-N5001 was jointly released as a non-genetically modified germplasm by the USDA-ARS and the North Carolina Agricultural Research Service in January 2023. USDA-N5001, experimental name N16-590, was derived from the hybridization of high-yielding breeding line N08-145 and high-protein breeding line Pro5-1. Across 22 environments of the 2019 and 2020 USDA Uniform Soybean Trials Southern States, USDA-N5001 yielded 105%, 98%, and 102% of the three checks 'Ellis', 'AG55X', and 'TN11-5140', respectively. On a zero-moisture basis, its protein content (425 g kg(-1)) was significantly higher (p < 0.05) than those of the checks (399-402 g kg(-1)). The meal protein content of USDA-N5001 (49.4%) was also significantly higher (p < 0.05) than the checks (46.7%-46.9%). The new release matured 2 days and 1 day later than Ellis and AG55X, respectively, but 5 days earlier than TN11-5140. USDA-N5001 is the first high-yielding, high-seed- and meal-protein MG V-Early (relative maturity 5.3) line developed by USDA-ARS in North Carolina. With the recent increases in production of MG V soybeans in the southeastern United States and the national focus on higher-meal protein lines, USDA-N5001 should be highly useful to soybean breeders and growers of conventional soybeans in the southeastern United States.

USDA-N7005 soybean [Glycine max (L.) Merr.] (Reg. no. GP-457, PI 699962) was released by the USDA-ARS and the North Carolina Agricultural Research Service in August 2021. USDA-N7005 is an early-maturity group VII, F-4-derived germplasm with excellent yield potential that traces 62.5% of its pedigree to Japanese accessions that are not part of the historical genetic base of U.S. soybean breeding. Currently, Japanese germplasm constitutes only a small portion of the U.S. soybean base. USDA-N7005 was derived from the cross of cultivar 'USDA-N7002' x Japanese cultivar 'Tamahikari'. USDA-N7005 traces 12.5% of its ancestry to Japanese landrace PI 416937 via USDA-N7002 and 50% to Japanese cultivar Tamahikari. USDA-N7005 is the second public release in the United States derived from Tamahikari. Over 13 environments of the United Soybean Board Southern Diversity Yield Trials and 19 test environments of the USDA Uniform Soybean Tests-Southern States, USDA-N7005 yielded 108% (p < .05) and 101% of the adapted parent cultivar USDA-N7002, respectively, and matured 2-3 d earlier. The new release also yielded 100% of check cultivars 'NC-Roy' and 'USDA-N7003CN' and 96% of cultivar 'NC-Dilday' in the Uniform Tests. USDA-N7005 was similar in height and lodging to parent USDA-N7002 but exhibited elevated seed oil content and larger seed size. USDA-N7005 was resistant to root-knot nematode and stem canker, with resistance comparable to that of resistant parent USDA-N7002. The superior agronomic performance and diverse pedigree of USDA-N7005 make it desirable parental stock for broadening the base of U.S. soybean breeding.

G11-7013 (Reg. no. GP-447, PI 699240) is a conventional maturity group (MG) VII soybean [Glycine max (L.) Merr.] line. It contains a 50% genetic background of an accession from South Africa by pedigree, with resistance to soybean cyst nematode race 3 (Heterodera glycines), southern root-knot nematode (Meloidogyne incognita), and stem canker (Diaporthe aspalathi) and high meal protein. G11-7013 was developed and released by the University of Georgia (UGA) Agricultural Experiment Stations in 2020. G11-7013 is an F-5-derived plant selection from 'Boggs' x PI 221717. G11-7013 consistently yielded more than the elite parent Boggs in UGA advanced yield trials. Across 25 environments in the United Soybean Board Southern Protein Diversity Yield Trials MG-VII, G11-7013 yielded a range of 93-104% of the elite check cultivar mean over 5 yr, with an average of 98% of check means. G11-7013 has a protein content of 436 g kg(-1), a meal protein value of 51%, and an oil content of 217 g kg(-1). G11-7013 exceeds the desired meal protein levels required for soybean and derives from a diverse genetic background. Because of its high yield, high protein content, disease resistance package, and diverse pedigree, G11-7013 can be used as a parental stock in both public and private sectors to develop high-yielding, high-meal-protein soybean cultivars.

Symbiotic nitrogen fixation of soybean (Glycine max (Merr.) L) commonly decreases in response to soil drying in advance of other plant processes. While a few soybean lines express nitrogen fixation drought tolerance, breeding for genetic variation is hampered by laborious phenotyping procedures. The objective of this research was to explore the potential of an initial screen for nitrogen fixation drought-tolerant genotypes based on a possible relationship with xylem-vessel diameter. The hypothesis was that nitrogen fixation drought-tolerance might result from fewer, large-diameter xylem vessels in the stem that are vulnerable to disrupted flow as water deficit develops. The disrupted flow could cause nitrogen products to accumulate in nodules resulting in negative feedback on nitrogen fixation rate. The proposed screen involved exposing de-rooted shoots to a suspension containing microspheres (45-53 μm diameter) and recording the decrease in transpiration rate as a result of microsphere xylem-blockage. Two soybean populations were tested. One population was progeny derived from mating of two parents with high and low nitrogen fixation drought sensitivity. A high correlation (R2 = 0.68; P<0.001) was found in this population between decreasing transpiration rate resulting from the microsphere treatment and increasing sensitivity of nitrogen fixation to soil drying. The second tested population consisted of 16 genotypes, most of which had been previously identified in germplasm screens as expressing nitrogen fixation drought tolerance. Nearly half of the lines in this second population were identified in the screen as showing minimum blockage of transpiration when exposed to the microspheres. Overall, these results showed the potential of using the microsphere screen to identify candidate genotypes expressing nitrogen fixation drought-tolerance.

USDA-N6005 soybean [Glycine max (L.) Merr.] (Reg. no. GP-442, PI 696388), is an F-5-derived early maturity group (MG) VI germplasm jointly released by the USDA-ARS and North Carolina Agricultural Research Service in January 2021. USDA-N6005 is a genetically diverse germplasm with 25% of its pedigree from Japanese cultivar Tamahikari and has high yield potential coupled with elevated seed and meal protein content. USDA-N6005 is the first MG VI release derived from Tamahikari. In the USDA Uniform Tests-Southern States during 2017-2018, USDA-N6005 yielded 102, 103, and 102% of the check cultivars NC-Dunphy, NC-Dilday, and NC-Roy, respectively. It had significantly better lodging resistance (1.5) than NC-Roy and NC-Dilday (2.6 and 2.5, respectively). The seed protein content on a dry basis of USDA-N6005 (424 g kg(-1)) was significantly higher than that of NC-Dunphy and NC-Dilday (392 and 383 g kg(-1), respectively). The estimated meal protein content (49.0%) of USDA-N6005 was significantly higher than that of NC-Dunphy and NC-Dilday (46.2 and 45.5%, respectively). Across the five environments of the 2016 USDA Preliminary Tests-Southern States, USDA-N6005 yielded 100 and 102% of check cultivars AG6534 and NC-Roy, respectively. This release should help to reverse the declining trend in genetic diversity and seed protein of U.S. soybean cultivars without negative impact on seed yield.

Soybean [Glycine max (L.) Merr.] lines R10-2436 (Reg. no. GP-439, PI 692971) and R10-2710 (Reg. no. GP-440, PI 692972) are high-yielding and drought-tolerant conventional germplasm released by the Arkansas Agricultural Experiment Station in February 2017. R10-2436 and R10-2710 have a relative maturity of 5.6 and 5.8, respectively. R10-2436 is an F-4 -derived line from the cross R01-52F x R02-6268F, and R10-2710 is an F-2 -derived line from R01-52F x 'USDA-N7002'. In 6 yr of testing, R10-2436 and R10-2710 significantly outyielded the maturity group 5 check mean under moderate water-deficit stress in Stuttgart, AR (2,893, 2,889, and 2,506 kg ha(-1), respectively) and were on a par with the checks under full irrigation in Stuttgart (4,644, 4,511, and 4,613 kg ha(-1), respectively) and in five additional irrigated Arkansas environments. The water-deficit treatment consisted of normal irrigation until blooming, after which irrigation was suspended for the rest of the season. In greenhouse pot studies, both releases exhibited sustained nitrogen fixation during a dry-down cycle. This trait was presumably inherited from their ancestor 'Jackson'. R10-2436 also exhibited slow wilting in multiple drought-stressed environments in Arkansas and North Carolina, likely inherited from PI 416937. Because of their yield potential under drought and irrigation, as well as their good agronomic characteristics, R10-2436 and R10-2710 can be easily incorporated in applied breeding programs to transfer drought tolerance into elite high-yielding cultivars.

USDA-N6004 (Reg. no. GP-441, PI 692264) is a conventional, late maturity group (MG) VI soybean [Glycine max (L.) Merr.] germplasm developed to increase the diversity of the genetic base of applied soybean breeding in North America. This germplasm was released by the USDA-ARS and the North Carolina Agricultural Research Service in September 2019. USDA-N6004 traces 50% of its pedigree to the large-seeded Japanese cultivar Blue Side and is the first U.S. release derived from this exotic accession, as Blue Side is not a part of the historic genetic base of U.S. soybean. USDA-N6004 has a yield potential and maturity similar to that of its adapted parent, 'NC-Roy'. Over 35 test environments of the USDA Uniform Soybean Tests-Southern States (Uniform Tests), USDA-N6004 yielded 99% of NC-Roy, matured 2 d earlier, and exhibited 3.9 g greater 100 seed weight than NC-Roy. Over 23 environments of the United Soybean Board Southern Diversity Yield Trials, USDA-N6004 yielded 97% of NC-Roy and 91% of the elite cultivar NC-Dilday. Seed protein and estimated meal protein content of the release were lower and seed oil content was higher than NC- Roy (its adapted parent) in the Uniform Tests. However, meal protein percentage of USDA-N6004 was above the industry minimum standard of 48%. Thus, this germplasm should prove valuable as parental stock in applied breeding. This soybean release is among the first in the United States developed via a combination of bulk breeding and pedigree selection.

As the risk of drought attributable to climate change increases, the development of high-yielding, drought-adapted cultivars will be critical for minimizing yield losses in crops like soybean (Glycine max (L.) Merr.). In this study, the ability of soybean genotypes to recover transpiration and leaf gas exchange capacity following re-watering from soil drying was investigated. The plants were subjected to controlled water-deficit stress and recovery in growth-chamber experiments. Transpiration was measured on five soybean genotypes and photosynthesis rates on two select genotypes. After water re-supply, transpiration was initially low but increased until a stable rate was reached on day 3, to about 50% to 100% of the rates of reference plants that had not been stressed. The largest difference in maximum transpiration recovery was between the varieties USDA-N8002 and Benning compared to the landrace Geden Shirazu, with Geden Shirazu having the lowest recovery. Photosynthesis and vapor-pressure-deficit response measurements did not show that restricted plant stomatal conductance was responsible for the limitation observed in Geden Shirazu recovery. Since all genotypes showed rapid recovery from water-deficit stress in 3 d, more rapid recovery was not indicated as a major candidate for improving soybean drought tolerance. However, the extent of recovery varied among genotypes and those genotypes that fully recovered to rates of well-watered plants such as Benning and USDA-N8002 would seemingly be advantageous for drought conditions.

USDA-N7004 (Reg. no. GP-438, PI 692263) is a conventional late maturity group VII soybean (Glycine max (L.) Merr.] germplasm with good yield potential, elevated seed protein content, and 25% exotic pedigree from Japanese cultivar Tamahikari (PI 423897). USDA-N7004 was jointly released as a non-GM germplasm by the USDA-ARS and the North Carolina Agricultural Research Service in September 2019. USDA-N7004, experimental name N10-711, was derived from a cross of USDA-ARS breeding lines NTCPR01-163 ('Dillon' x Tamahikari) and N03-832. Across 27 environments of the USDA Uniform Soybean Tests-Southern States (Uniform Tests), USDA-N7004 yielded 97 and 94% of elite checks 'N7003CN' and 'NC-Wilder', respectively. Over 20 environments of United Soybean Board Southern Diversity Yield Trials (Diversity Trials), USDA-N7004 yielded 98 and 94% of the same two checks, respectively. In the Uniform Tests, seed protein content of USDA-N7004 (421 g kg(-1)) was significantly higher than N7003CN and NC-Wilder on a zero-moisture basis (405 and 399 g kg(-1,) respectively). The meal protein content of USDA-N7004 (49%) was significantly higher than N7003CN or NC-Wilder (47%) in the Uniform Tests as well as in the Diversity Trials. USDA-N7004 should be a useful parent in breeding programs aimed at broadening the genetic base of soybean along with improving seed protein and seed yield.

There are two species of Bradyrhizobium that nodulate soybean [Glycine max (L.) Merr.] and fix nitrogen (N): B. japonicum and B. elkanii. Bradyrhizobium elkanii is endemic to soils in the southeastern region of the United States. Some strains of B. elkanii produce rhizobitoxine (RT), a toxin that causes chlorosis on newly developing trifoliates of some field-grown soybean, in root nodules. Some soybean genotypes are resistant to rhizobitoxine-induced (RI) chlorosis. The objective of this research was to determine the inheritance of soybean resistance to RI chlorosis. Crosses were made between resistant and susceptible cultivars. Progeny were identified as susceptible, resistant, or segregating in the first, second, and third self-pollinated generations. All F-1 hybrids from crosses between resistant and susceptible soybean exhibited seedling chlorosis, indicating that genes for resistance to chlorosis are recessive. The F-2 progeny segregated in a ratio of nine susceptible to seven resistant, indicating that there are two genes responsible for the soybean resistance to RI chlorosis. This ratio was confirmed in F-2:3 population screening. One hundred forty-one simple sequence repeat (SSR) markers polymorphic in both a susceptible parent and a resistant parent were used to locate the genes responsible for resistance to chlorosis. A gene found near marker Satt 657 on linkage group (LG) F (chromosome 13) explained a statistically significant 32% of the phenotypic variation among F-2 plants based on the p-value and R-2 of a single factor ANOVA. The second gene was not located.

The genetic diversity of North American soybean cultivars has been largely influenced by a small number of ancestors. High yielding breeding lines that possess exotic pedigrees have been developed, but identifying beneficial exotic alleles has been difficult as a result of complex interactions of yield alleles with genetic backgrounds and environments as well as the highly quantitative nature of yield. PI 416937 has been utilized in the development of many high yielding lines that have been entered into the USDA Southern States Uniform Tests over the past ~20 years. The primary goal of this research was to identify genomic regions under breeding selection from PI 416937 and introduce a methodology for identifying and potentially utilizing beneficial diversity from lines prevalent in the ancestry of elite cultivars. Utilizing SoySNP50K Infinium BeadChips, 52 high yielding PI 416937-derived lines as well as their parents were genotyped to identify PI 416937 alleles under breeding selection. Nine genomic regions across three chromosomes and 17 genomic regions across seven chromosomes were identified where PI 416937 alleles were under positive or negative selection. Minimal significant associations between PI 416937 alleles and yield were observed in replicated yield trials of five RIL populations, highlighting the difficulty of consistently detecting yield associations.

A number of soybean varieties traditionally bred for resistance to various soybean arthropod pests have been identified as resistant to Megacopta cribraria (F.) (Hemiptera: Plataspidae). However, the mechanisms of host-plant resistance (HPR) in this system are not understood. The goal of this study was to identify the mechanisms of resistance by examining the role of plant volatile organic compounds (VOCs) and free amino acids (FAAs) among 16 soybean varieties. Choice and no-choice cage experiments identified several soybean varieties that demonstrated antixenosis as well as antibiosis. However, resistance varied over time in certain soybean varieties, such as N02-7002 and PI567352B. Mean nymph number from choice experiments had positive correlations with the FAAs asparagine, tryptophan, alanine, phenylanaline, and serine; negative correlation with leucine and threonine. Four plant volatiles, hexanal, 2-pentylfuran, beta-cyclocitral, and cis-9-hexadecenal, were positively correlated with subsequent nymph development, whereas n-hexadecenoic acid was negatively correlated with nymph number only, in adult choice cage experiments. This study contributes to understanding the mechanisms of HPR through associations with plant VOCs and FAAs in relation to M. cribraria development and provides useful knowledge for developing soybean varieties for M. cribraria management.

Drought stress causes the greatest soybean [Glycine max (L.) Merr.] yield losses among the abiotic stresses in rain-fed U.S. growing areas. Because less than 10% of U.S. soybean hectares are irrigated, combating this stress requires soybean plants which possess physiological mechanisms to tolerate drought for a period of time. Phenotyping for these mechanisms is challenging, and the genetic architecture for these traits is poorly understood. A morphological trait, slow or delayed canopy wilting, has been observed in a few exotic plant introductions (PIs), and may lead to yield improvement in drought stressed fields. In this study, we visually scored wilting during stress for a panel of 162 genetically diverse maturity group VI-VIII soybean lines genotyped with the SoySNP50K iSelect BeadChip. Field evaluation of canopy wilting was conducted under rain-fed conditions at two locations (Athens, GA and Salina, KS) in 2015 and 2016. Substantial variation in canopy wilting was observed among the genotypes. Using a genome-wide association mapping approach, 45 unique SNPs that tagged 44 loci were associated with canopy wilting in at least one environment with one region identified in a single environment and data from across all environments. Several new soybean accessions were identified with canopy wilting superior to those of check genotypes. The germplasm and genomic regions identified can be used to better understand the slow canopy wilting trait and be incorporated into elite germplasm to improve drought tolerance in soybean.

Megacopta cribraria (F.) (Hemiptera: Plataspidae) is an invasive pest of soybean that has spread across the southeastern United States since its initial discovery in 2009 in Georgia. Previous studies in the southeastern states have documented both the population dynamics of this pest and host plant resistance (HPR) among soybean varieties, although the specific mechanisms of HPR remain unknown. The objectives of this study were, therefore, to 1) quantify field resistance to M. cribraria in multiple soybean varieties in two states previously affected by severe M. cribraria infestations, North Carolina (NC) and South Carolina (SC); and 2) study the role of soybean trichome density in imparting resistance against M. cribraria. Soybean variety 'Camp' was least attractive to M. cribraria, through time and locations, suggesting consistent resistance. Other varieties showed variable performance among the locations and sampling dates. A significant difference in trichome density was evident. However, there was no correlation between trichome density and M. cribraria infestation. Compared to a previously published study in the same location, when M. cribraria adults emerging from overwintering dispersed into soybeans, in our study only first-generation adults dispersed into soybeans. Considering the current trend of significantly lower M. cribraria infestation rates in North and South Carolina, this pest may be finally succumbing to indigenous natural enemies and should be managed by incorporating integrated pest management tactics, such as HPR, that help conserve natural enemy populations.

Soybean [Glycine max (L.) Merr.] is an important source of protein and vegetable oil. Genetic improvement of soybean seed yield and composition are ultimate breeding goals. During the past 80 yr, breeders have selected for high yield and other desired traits to make genetic improvements. To quantify the genetic changes to seed yield, yield stability, and other important agronomic and end‐use quality traits, we evaluated 93 soybean cultivars in Maturity Groups (MG) V, VI, and VII that were released from 1928 to 2008. Replicated yield trials specific for each MG set of cultivars were conducted during 2010 to 2011 in a total of 27 southeastern US year‐location environments. A mixed linear model was used to calculate best linear unbiased predictors (BLUPs) for each cultivar for each measured trait within each MG. Regressed cultivar effect BLUPs of each trait by year of cultivar release revealed positive linear trends for annualized genetic yield gains of 17.6, 13.5, and 10.3 kg ha−1 yr−1 for MG V, VI, and VII, respectively. Averaged across MGs, the annualized rate of genetic gain was estimated to be 13.7 kg ha−1 yr−1. Yield stability analyses revealed significant differences in regression coefficients (b), which were >1.0 for newer cultivars but <1.0 for older cultivars. Overall, the average annualized rate of genetic gains for seed yield reported herein are equivalent to those previously reported, indicating that a yield plateau has not been reached for MG V, VI or VII soybean cultivars.

USDA‐Max × Soja Core Set‐1 (USDA‐MxS‐CS1‐1 to USDA‐MxS‐CS1‐17 [Reg. No. GP‐417 to GP‐433, PI 689053 to PI 689069]) is a group of 17 interspecific breeding lines developed from the hybridization of lodging‐resistant soybean cultivar N7103 [Glycine max (L.) Merr.] with wild soybean plant introduction PI 366122 [G. soja Siebold & Zucc.]. These materials were released by the USDA‐ARS and the North Carolina Agricultural Research Service (March 2017) to expand the North American soybean breeding pool. The full‐sib breeding lines are 50% wild soybean by pedigree and developed through bulk breeding and pedigree selection. Marker analysis of 2455 well‐distributed polymorphic single‐nucleotide polymorphism loci revealed that individual breeding lines ranged from 21 to 40% alleles derived from wild soybean. Collectively, most of the wild soybean genome was transferred to the core set in that 5, 10, and 17 breeding lines captured 83, 98, and 99% of G. soja–derived polymorphic alleles. Physical linkage maps suggested that extensive recombination occurred between the G. max and G. soja genomes. The 17 breeding lines are well adapted to the southeastern United States, exhibited seed yield ranging from 75 to 97% of the domesticated parent, and are group VI or VII maturity. Some breeding lines displayed increased seed protein, oil, or methionine content, and all exhibited increased seed size as compared to the domesticated parent. The novel genetic diversity, positive agronomic performance, and improved seed composition of these lines suggest that they are valuable genetic resources for US soybean breeding.