Soybean Research Articles

First Report of Seed Decay Caused by Diaporthe ueckeri on soybean in Brazil.

A survey of Diaporthe/Phomopsis Complex (DPC) species was carried out on 479 asymptomatic soybean (Glycine max (L.) Merrill) seed samples collected from commercial soybean fields in the states of Santa Catarina (20 counties) and Rio Grande do Sul (41 counties), in the 2020/21 (n=186), 2021/22 (n=138) and 2022/23 (n=155) seasons from 120 cultivars. The seeds were provided by seed producers who collected according to the sampling standard of the Ministry of Agriculture, Livestock and Food Supply. From each sample received, 200 symptomless seeds were randomly sorted out. The seeds were surface disinfected by immersion in a sodium hypochlorite solution (1%) for two minutes and placed on Potato Dextrose Agar (PDA). The plates were incubated for 7 days at 23°C with a photoperiod of 12-h. The average prevalence of 73.7% of DPC-infected seeds. Colonies were isolated by transferring mycelial tips to PDA and incubating for 14 days at 25ºC in a 12-h photoperiod. One colony (isolate MEMR0500) had morphological characteristics similar to those reported in Lopez-Cardona (2021). This isolate had a floccose, dense colony ranging from grayish beige to brown with greenish regions and black globose pycnidia (3 to 4 pycnidia/cm²). Alpha-conidia, 5.1 to 7.0 µm x 1.5 to 2.8 µm, were observed after 30 days and were hyaline, aseptate and fusiform (Figure S1). No beta-conidia were observed. Soybean plants of cultivars BMX Cromo IPRO, BMX Zeus IPRO, BRS 5804 RR, FPS 1867 IPRO and NEO 750 IPRO were tested for pathogenicity using the toothpick inoculation method (Siviero and Menten 1995). Non-colonized toothpicks served as a negative control. Plants were incubated for four days at 25°C and 90% relative humidity. Elongated 1.0 to 2.5 cm x 0.5 to 0.9 cm lesions gray-brown/reddish-brown with a depressed center were observed in all inoculated cultivars. The fungus was reisolated and the characteristics of the colonies were identical to those previously isolated. For molecular characterization, DNA was extracted from the mycelia using the CTAB method (Doyle and Doyle 1990). End-point PCR was performed using GoTaq® Flexi DNA Polymerase (Promega, USA) and primer pairs, ITS-4F/ITS-5, T2/Bt2b and EF1-728F/EF1-986R to amplify the internal transcribed spacer (ITS) (Costamilan et al. 2008), β-tubulin (TUB2) (Glass and Donaldson 1995), and translation elongation factor 1-α (TEF1) (Carbone and Kohn 1999) genes, respectively. The amplified fragments were sequenced and submitted to blast search (https://blast.ncbi.nlm.nih.gov/Blast.cgi) with the sequences available in GenBank. The fragment from ITS (accession number OR912979) showed 99.8% (549/582 bp) identity with Diaporthe ueckeri Udayanga & Castl. [as 'ueckerae'] [syn. D. miriciae R.G. Shivas, S.M. Thomps. & Y.P. Tan] isolate FAU656 (Ac. N. KJ590726). The sequence of TEF (Ac. N. PP372869) showed 99.7% (339/355 bp) identity with D. ueckeri FAU656 (Ac. N. KJ590747), and of TUB (Ac. N. PP372870) showed 98.9% (436/536 bp) identity with D. ueckeri FAU656 (Ac. N. KJ610881). A phylogenetic tree with amplified sequences of each gene and the corresponding representative sequences from the DPC was constructed in MEGA X (Kumar et al. 2018). The MEMR0500 isolate was clustered only with the D. ueckeri clade, confirming the identity of the fungus (Figure S2). In Brazil, this is the first report of the association of this pathogen with soybean seeds. In other countries, this pathogen has been identified as the causal agent of stem canker (Mena et al. 2020; Lopez-Cardona et al. 2021). Further research is needed to analyze the risk of this seed-associated pathogen.

Comparative Analysis Highlights Uniconazole’s Efficacy in Enhancing the Cold Stress Tolerance of Mung Beans by Targeting Photosynthetic Pathways

Soybean (Glycine max) and mung bean (Vigna radiata) are key legumes with global importance, but their mechanisms for coping with cold stress—a major challenge in agriculture—have not been thoroughly investigated, especially in a comparative study. This research aimed to fill this gap by examining how these two major legumes respond differently to cold stress and exploring the role of uniconazole, a potential stress mitigator. Our comprehensive approach involved transcriptomic and metabolomic analyses, revealing distinct responses between soybean and mung bean under cold stress conditions. Notably, uniconazole was found to significantly enhance cold tolerance in mung bean by upregulating genes associated with photosynthesis, while its impact on soybean was either negligible or adverse. To further understand the molecular interactions, we utilized advanced machine learning algorithms for protein structure prediction, focusing on photosynthetic pathways. This enabled us to identify LOC106780309 as a direct binding target for uniconazole, confirmed through isothermal titration calorimetry. This research establishes a new comparative approach to explore how soybean and mung bean adapt to cold stress, offers key insights to improve the hardiness of legumes against environmental challenges, and contributes to sustainable agricultural practices and food security.

First report of Colletotrichum chlorophyti causing soybean anthracnose in Brazil.

Soybean [Glycine max (L.) Merr.] is one of the world's five major food crops, and Brazil produces the highest share at around 42%. Anthracnose caused by Colletotrichum is an important limiting factor to soybean production. In November 2013, anthracnose symptoms, characterized by brown irregular-shaped lesions on petioles, stems, and pods were observed in soybean fields (1% of incidence) in Vera, Mato Grosso State, Brazil. From the five plants gathered in the field, three leaves along with their corresponding petioles were meticulously chosen for the removal of symptomatic tissues. Sampling of these tissues involved carefully cutting a 0.5 × 0.5 cm fragment in the lesion area. The fragments were disinfected with 70% ethanol for 1 min, followed by 1% sodium hypochlorite for 2 min. Then the fragments were rinsed three times in sterile distilled water, placed on water-agar, and incubated at 25 °C for four days, in a 12/12 h photoperiod. Hyphal tips were transferred to potato dextrose agar (PDA) plates and incubated as previously described for seven days. A Colletotrichum sp. single-spore isolate (LFN0461) was selected, grown, preserved in filter paper, and stored at -80 °C. In 2023, it was reactivated for molecular characterization. On PDA, colony showed a rough-like mycelial growth, violaceous-black (front/reverse), with curved-shaped conidia 14.7 - 28.2 × 2.1 - 8.96 µm (average 18.4 × 4.7 µm). The DNA was extracted from 10-day-old mycelium using the cetyltrimethylammonium bromide (CTAB) method. The rDNA internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), histone (HIS3), and β-tubulin 2 (TUB2) regions were amplified by polymerase chain reaction (PCR), using the primer pairs ITS-1F + ITS-4 (Gardes and Bruns 1993; White et al. 1990), GDF1 + GDR1 (Guerber et al. 2003), CYLH3F + CYLH3R (Crous et al. 2006), and Bt2A + Bt2B (Glass and Donaldson 1995), respectively. The sequences were deposited in the GenBank database (accession numbers: PP209207 - ITS; PP213392 - GAPDH; PP213393 - HIS3; MN688797 - TUB2). The reconstruction of the multilocus phylogenetic tree revealed that the LFN0461 isolate clustered with C. cholorophyti reference strain (IMI 103806) with 99.9% of Bayesian probability. Given the seed-borne nature of soybean anthracnose (Boufleur et al. 2021; Yang et al. 2013), pathogenicity tests were carried out by soybean seeds inoculation. Fifty seeds of NS6220 IPRO (Nidera) cultivar were inoculated by water restriction method, with LFN0461 colonies grown on PDA amended with mannitol (Machado et al. 2004), while 50 seeds were placed on PDA amended with mannitol as negative control. Soybean seeds remained in contact with the inoculum for 48 hours. Subsequently, seeds were sown in 2 L pots (n = 10) containing sterilized substrate, which were placed in a greenhouse at 25 ± 5 ºC. After 10 days, inoculated soybean seedlings exhibited characteristic necrotic lesions on cotyledons and hypocotyls, while negative control plants remained asymptomatic. Colletotrichum chlorophyti was successfully reisolated from the symptomatic tissues. Currently, C. chlorophyti has been reported to cause soybean anthracnose and infect seeds in the United States (Yang et al. 2013, 2012). Although this pathogen has not been reported since our first observation in 2013 in Brazil, many Colletotrichum isolates are misidentified due to reliance on morphology (Boufleur et al. 2021). To our knowledge, this study is the first report of C. chlorophyti causing soybean anthracnose in Brazil, joining a new group of emergent Colletotrichum spp. associated with this disease.

Identification and Candidate Gene Evaluation of a Large Fast Neutron-Induced Deletion Associated with a High-Oil Phenotype in Soybean Seeds.

Since the dawn of agriculture, crops have been genetically altered for desirable characteristics. This has included the selection of natural and induced mutants. Increasing the production of plant oils such as soybean (Glycine max) oil as a renewable resource for food and fuel is valuable. Successful breeding for higher oil levels in soybeans, however, usually results in reduced seed protein. A soybean fast neutron population was screened for oil content, and three high oil mutants with minimal reductions in protein levels were found. Three backcross F2 populations derived from these mutants exhibited segregation for seed oil content. DNA was pooled from the high-oil and normal-oil plants within each population and assessed by comparative genomic hybridization. A deletion encompassing 20 gene models on chromosome 14 was found to co-segregate with the high-oil trait in two of the three populations. Eighteen genes in the deleted region have known functions that appear unrelated to oil biosynthesis and accumulation pathways, while one of the unknown genes (Glyma.14G101900) may contribute to the regulation of lipid droplet formation. This high-oil trait can facilitate the breeding of high-oil soybeans without protein reduction, resulting in higher meal protein levels.

Analysis of ion transport properties of Glycine max HKT transporters and identifying a regulation of GmHKT1;1 by the non-functional GmHKT1;4.

The HKT transporter plays an important role for plants in response to salt stress, but the transport property of the soybean HKT transporters at the molecular level is still unclear. Here, using Xenopus oocyte as a heterologous expression system and two-electrode voltage-clamp technique, we identified four HKT transporters, GmHKT1;1, GmHKT1;2, GmHKT1;3, and GmHKT1;4, which all belong to type I subfamily, but having distinct ion transport properties. While GmHKT1;1, GmHKT1;2 and GmHKT1;3 function as Na+ transporters, GmHKT1;1 is less selective against K+ than the two other transporters. Astonishingly, GmHKT1;4, which lacks transmembrane segments and has no ion permeability, is significantly expressed, and its gene expression pattern is different from the other three GmHKTs under salt stress. Interestingly, GmHKT1;4 reduced the Na+/K+ currents mediated by GmHKT1;1. Further study showed that the transport ability of GmHKT1;1 regulated by GmHKT1;4 was related to the structural differences in the first intracellular domain and the fourth repeat domain. Overall, we have identified one unique GmHKT member, GmHKT1;4, which modulates the Na+ and K+ transport ability of GmHKT1;1 via direct interaction. Thus, we have revealed a new type of HKTs interaction model for altering their ion transport properties.

Profitability of foliar fungicides in double crop soybean under low-disease environments

Double-crop soybean production involves planting soybean (Glycine max) directly following winter wheat (Triticum aestivum) harvest. Frogeye leaf spot (FLS), caused by Cercospora sojina, is an important late-season foliar disease affecting soybean fields in the United States. In some instances, foliar fungicides have been used in double-crop soybean production with little to no FLS present, raising questions on the profitability of these applications. This study analyzed yield data from 25 fungicide trials across five states (Illinois, Indiana, Kentucky, Missouri, and Tennessee) conducted under low FLS pressure, from 2008 to 2021, on double-crop soybean. Fungicide classes evaluated in the trials included quinone outside inhibitors (QoI), demethylation inhibitors (DMI), and methyl benzimidazole carbamates (MBC) applied alone, and mixtures of chemistry classes that included DMI+succinate dehydrogenase inhibitor (SDHI), MBC+DMI, QoI+DMI, and QoI+DMI+SDHI. A network meta-analytic model estimated yield differences between fungicide-treated and nontreated plots, which ranged from -28 to 72 kg/ha among the fungicide treatments. Negative yield response values were estimated for the single fungicide classes MBC (-15.7 kg/ha) and QoI (-28.4 kg/ha). Yield difference as high as 72.8 kg/ha was estimated only for DMI+SDHI. Economic analyses indicated that, due to the lower yield responses, probabilities of breaking even were lower than 50% for all fungicide treatments, regardless of the fungicide cost or soybean sale price. Therefore, the low yield responses associated with foliar fungicides in low-disease environments linked to the higher risk of not offsetting the costs, suggest that growers should consider disease risk prior to making the fungicide application.

Registration of R18‐14147: A high‐protein conventional soybean germplasm line

AbstractR18‐14147 (Reg. no. GP‐528, PI 705143) is a high‐protein conventional soybean [Glycine max (L.) Merr.] germplasm of maturity group Mid‐IV developed and released by the University of Arkansas System – Division of Agriculture Research & Extension in 2023. The germplasm is an F3:4 selection from the cross LG10‐3671‐1 × R09‐430. Plants of R18‐14147 have an indeterminate growth habit with purple flowers, gray pubescence, brown pod wall, and imperfect black hilum. Across 28 environments in Arkansas (2019–2022), R18‐14147 yield averaged 4482 kg ha−1, with broad adaptability and yield stability. Seed of R18‐14147 contains on average 429 g kg−1 and 191 g kg−1 of protein and oil on a dry weight basis, respectively, and seed weight is 15.2 g 100 seeds−1. The average seed protein content of this line is 8%–27% higher than the average protein content of the check cultivars used in various trials to evaluate R18‐14147. Additionally, R18‐14147 has been identified as resistant to stem canker. R18‐14147 presents soybean growers in the mid‐southern United States with a promising germplasm alternative combining high yield potential and elevated seed protein content for alternative crop rotation in herbicide‐tolerant cultivar systems, offering potentially seed‐saving cost benefits and serving as a valuable germplasm for new cultivar development.

Genetic adaptation of phenological stages in Chinese and European elite soybeans (Glycine max [L.] Merr.) across latitudes in Central Europe

Genetic adaptation of phenological stages in Chinese and European elite soybeans (<scp><i>Glycine max</i></scp> [L.] Merr.) across latitudes in Central Europe

Bacillus suppresses nitrogen efficiency of soybean-rhizobium symbiosis through regulation of nitrogen-related transcriptional and microbial patterns.

The regulation of legume-rhizobia symbiosis by microorganisms has obtained considerable interest in recent research, particularly in the common rhizobacteria Bacillus. However, few studies have provided detailed explanations regarding the regulatory mechanisms involved. Here, we investigated the effects of Bacillus (Bac.B) on Bradyrhizobium-soybean (Glycine max) symbiosis and elucidated the underlying ecological mechanisms. We found that two Bradyrhizobium strains (i.e. Bra.Q2 and Bra.D) isolated from nodules significantly promoted nitrogen (N) efficiency of soybean via facilitating nodule formation, thereby enhanced plant growth and yield. However, the intrusion of Bac.B caused a reverse shift in the synergistic efficiency of N2 fixation in the soybean-Bradyrhizobium symbiosis. Biofilm formation and naringenin may be importantin suppression of Bra.Q2 growth regulated by Bac.B. In addition, transcriptome and microbiome analyses revealed that Bra.Q2 and Bac.B might interact to regulateN transport and assimilation, thus influence the bacterial composition related to plant N nutrition in nodules. Also, the metabolisms of secondary metabolites and hormones associated with plant-microbe interaction and growth regulation were modulated by Bra.Q2 and Bac.B coinoculation. Collectively, we demonstrate that Bacillus negatively affects Bradyrhizobium-soybean symbiosis and modulate microbial interactions in the nodule. Our findings highlight a novel Bacillus-based regulation to improve N efficiency and sustainable agricultural development.

Productivity of soybean (Glycine max) varieties under different levels of integrated nutrient management

The present experiment was conducted during the rainy (kharif) seasons of 2019 and 2020 at Bidhan Chandra Krishi Viswavidyalaya, West Bengal to study the performance of various soybean [Glycine max (L.) Merr.] varieties under different levels of integrated nutrient management. A three-time repeated factorial randomized block design (F-RBD) was used for the experiment having 3 varieties (Factor 1), viz. PS-1225; YEZIN-15; and PS-24 and 5 nutrient management treatments (Factor 2), viz. 100% recommended dose of fertilizer (RDF); 75% RDF+3 t/ha farmyard manure (FYM); 75% RDF+1.5 t/ha vermicompost; 75% RDF+3 t/ha FYM+25 kg/ha ZnSO4; and 75% RDF+1.5 t/ha vermicompost+25 kg/ha ZnSO4. Findings explored that 75% RDF+1.5 t/ha vermicompost+25 kg/ha ZnSO4 supply in PS-24 variety ensured highest seed yield (2601 kg/ha), stover yield (5241 kg/ha) and harvest index (33.17%) owing from high nutrient uptakes. Further, production economics stated that PS-24 cultivated with 75% RDF+1.5 t/ ha vermicompost+25 kg/ha ZnSO4 supply registered maximum net return (₹42994/ha) and benefit cost (B:C) ratio (2.32) indicating its suitability in eastern Indian condition.

Identification of Flavor Compounds from Soybean Peel Flour (Glycine max L. Merr) with the Addition of Kaffir Lime Leaves in the Blanching Process

Identification of Flavor Compounds from Soybean Peel Flour (Glycine max L. Merr) with the Addition of Kaffir Lime Leaves in the Blanching Process

Soybean ethylene response factors GmENS1 and GmENS2 promote nodule senescence.

The final phase in root nodule development is nodule senescence. The mechanism underlying the initiation of nodule senescence requires further elucidation. Here, we investigated the intrinsic signals governing soybean (Glycine max L. Merr.) nodule senescence, uncovering ethylene as a key signal in this intricate mechanism. Two AP2/ERF transcription factor genes, GmENS1 and GmENS2 (Ethylene-responsive transcription factors required for Nodule Senescence), exhibit heightened expression levels in both aged nodules and nodules treated with ethylene. Overexpression of either GmENS1 or GmENS2 accelerated senescence in soybean nodules, whereas the knockout or knockdown of both genes delayed senescence and enhanced nitrogenase activity. Furthermore, our findings indicated that GmENS1 and GmENS2 directly bind to the promoters of GmNAC039, GmNAC018, and GmNAC030, encoding three NAC transcription factors essential for activating soybean nodule senescence. Notably, the nodule senescence process mediated by GmENS1 or GmENS2 overexpression was suppressed in the soybean nac039/018/030 triple mutant compared with the wild-type control. These data indicate GmENS1 and GmENS2 as pivotal transcription factors mediating ethylene-induced nodule senescence through the direct activation of GmNAC039/GmNAC018/GmNAC030 expression in soybean.

Effects of Salinity on Physicochemical Properties, Flavor Compounds, and Bacterial Communities in Broad Bean Paste-Meju Fermentation.

Broad bean paste (BBP) is a traditional fermented soy food, and its high salt content not only prolongs the fermentation time but also threatens human health. In this study, three BBP-meju with different salt concentrations were prepared, and the effects of varying salinity on fermentation were comprehensively compared. The results showed that salt-reduced fermentation contributed to the accumulation of amino acid nitrogen, reducing sugars, free amino acids, and organic acids. Alcohols, esters, aldehydes, and acids were the main volatile flavor compounds in BBP-meju, and the highest total volatile flavor compounds were found in medium-salt meju. Bacillus, Staphylococcus, Aspergillus, and Mortierella were the dominant microbial communities during fermentation, and there were also three opportunistic pathogens, Enterobacter, Pantoea, and Brevundimonas, respectively. According to Spearman correlation analysis, Wickerhamomyces, Bacillus, Staphylococcus, and Mortierella all showed highly significant positive correlations with ≥3 key flavor compounds, which may be the core functional flora. Furthermore, the dominant microbial genera worked synergistically to promote the formation of high-quality flavor compounds and inhibit the production of off-flavors during salt-reduced fermentation. This study provides a theoretical reference for the quality and safety control of low-salt fermented soy foods.

Recommended Diet Therapy of Mediterranean Diet (MD) and Low Carbohydrate Diet (LCD)

To maintain health and achieve longevity, an adequate diet is crucial, such as the Mediterranean diet (MD) and the low-carbohydrate diet (LCD). The MD is characterized by whole grains, fruits, vegetables, less red meat, more fish, and four eggs per week. The MD may reduce the risk of heart disease, stroke, dementia, and depression. The LCD shows remarkable weight reduction in a short period, but there may be a probable rebound effect within six months. In Japanese cuisine, the intake of fermented soy foods such as natto and miso can lower the risk of death. As a recommendation, the LCD can be started first, followed by the MD for the long term.

Effect of row distance on plant architecture, weed suppression and yield of silage maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) in a pesticide-free cultivation system in Southern Germany

Conventional farming prioritizes monocultures and synthetic chemicals to secure high yields. However, there are a growing number of initiatives worldwide to reduce or eliminate the use of pesticides. One option for pesticide-free weed management is the adjustment of sowing pattern (row distance, plant arrangement, sowing density). This study investigated the effects of an equal distance sowing versus a normal distance sowing (EDS and NDS1) at constant sowing density on plant morphology, growth and yield of silage maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) as well as the weed occurrence. Therefore, a 3-year (2020-2022) pesticide-free, field experiment was conducted at the Heidfeldhof Research Station, University of Hohenheim, Germany. In silage maize, neither plant architecture nor biomass yield showed significant differences between EDS with 0.375 m and NDS with 0.75 m row distance. In contrast, soybean developed a bushier plant architecture with more branches and shorter petioles in EDS with 0.15 m compared to plants in NDS with 0.50 m row distance, demonstrating phenotypic plasticity. A higher number of pods per plant (EDS: 28.05; NDS: 22.73) and seed yield (EDS: 406.58 g m-2; NDS: 389.34 g m-2) indicated the potential for increased yields applying EDS. Crop competitiveness against weeds was higher in EDS than in NDS, especially early in the growing season. The results highlight the importance of EDS as a valuable tool for pesticide-free, non-organic cropping systems through positive effects on crop yield and efficient weed control.

Profile of mineral nutrients and proteins in soybean seeds (Glycine max (L.) Merrill): Insights from 95 varieties cultivated in Brazil

Soybean (Glycine max (L.) Merrill) stands out as a major source of protein meal for human and animal nutrition. Nevertheless, the increase in soybean yield has been accompanied by a reduction in protein content over the last decades. In this study, we determined the profile of mineral nutrients and total protein in 95 soybean varieties broadly cultivated in Brazil, the world’s largest soybean producer and exporter, to identify a possible association between seed mineral and protein content. Energy-dispersive X-ray fluorescence spectroscopy (EDXRF) was employed to determine the concentration of macro, i.e., potassium (K), phosphorus (P), sulphur (S), calcium (Ca), and micronutrients, i.e., iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu). The protein content of soybean seeds was evaluated using the Dumas method. The correlation and clustering between nutrients and proteins were determined using both univariate and multivariate non-parametric tests. Both protein and nutrient concentrations were not homogeneous across soybean seed varieties. It was also revealed that the higher the seed protein content, the higher the S, Mn, and Zn concentrations, whereas the opposite trend was observed for K and P. These results indicate an intricate association between S, Zn, Mn, and total protein content in soybean seeds.

Protein homeostasis and cell wall remodeling in response to jasmonate and gibberellin signals improve flood tolerance in soybean (Glycine max L.)

Protein homeostasis and cell wall remodeling in response to jasmonate and gibberellin signals improve flood tolerance in soybean (Glycine max L.)

The Effect of some Herbicides and Spraying Periods on the Growth and Weeds of a Soybean Crop (Glycin max L.)

The Effect of some Herbicides and Spraying Periods on the Growth and Weeds of a Soybean Crop (Glycin max L.)

Registration of high‐yielding, high‐protein soybean germplasm USDA‐N7007 derived from wild soybean PI 366122

AbstractUSDA‐N7007 is a non‐GM, maturity group (MG) VII soybean [Glycine max (L.) Merr.] (Reg. no. GP‐529, PI 705147) germplasm released by the USDA Agricultural Research Service in conjunction with the North Carolina Agricultural Research Service in December of 2023. USDA‐N7007 is a high‐yielding, high‐protein germplasm derived from wild soybean (Glycine soja Siebold &amp; Zucc; PI 366122) and small‐seeded MG VII USDA cultivar N7103. Over 47 combined testing environments of the USDA Southern Uniform and USB Protein Diversity Tests (2018–2021), USDA‐N7007 yielded 98% of the check mean and 102% of the test mean. The average protein content of USDA‐N7007 was significantly higher (432 g kg−1) than the average check means of 402 g kg−1 and 413 g kg−1 in the USDA Southern Uniform and USB Protein Diversity Tests, respectively. Across both tests (2019–2021), the release was significantly (p &lt; 0.05) higher in protein (+7 g kg−1), with 9% higher seed yield (+242 kg ha−1) than the recurrent parent N7103. USDA‐N7007 is resistant to lodging, southern root‐knot nematode, and stem canker. To the best of our knowledge, this is the first US release clearly demonstrating that the wild soybean genome can be incorporated into an elite cultivar to increase seed protein without a negative effect on seed yield. This release is a truly novel and valuable resource for development of future US soybean cultivars because it will be useful to improve both genetic diversity and seed protein simultaneously without a negative effect on seed yield.

Delayed photosynthesis response causes carbon assimilation reduction in soybean under fluctuating light

Plants experience dynamic light environments in the field, and the mechanisms for physiological and biochemical acclimation to fluctuating light (FL) vary among species. How soybean (Glycine max (L.) Merr.) integrates multiple physiological changes to acclimate to FL remains unclear. This study evaluated the impact of FL conditions on soybean morphology and photosynthetic characteristics by analyzing changes in photosynthetic gas exchange parameters and chlorophyll (Chl) a fluorescence parameters under alternating high and low light conditions. Results showed that soybeans subjected to FL conditions had low dry matter mass, small and thin leaves, and a low Chl a to Chl b ratio, resembling the traits of soybeans grown in low-light environments. However, their photosynthetic gas exchange rates and photosynthetic capacity remained constant, which was not the case under consistent low-light conditions. The adaptation processes for fluctuating and lowlight conditions are distinct. Correlation analyses indicated that the drop in carbon assimilation under FL primarily resulted from two aspects: the speed of recovery in stomatal conductance when transitioning to bright light and the slow relief of nonphotochemical quenching as light levels decreased. Thus, the decrease in carbon assimilation under FL conditions cannot be ascribed to adjustments during low-light phases but is due to a lag in photosynthetic response.