A new soybean [Glycine max (L.) Merr.] cultivar, ‘Dadrim,’ was developed by the National Institute of Crop and Food Science (NICS). ‘Dadrim’ is characterized by its superior suitability for tofu processing and high adaptability to mechanized cultivation. This cultivar ‘Milyang374’ was developed using the pedigree method from an artificial cross made in 2012 between ‘Milyang231’ and ‘Chamol.’ Its agronomic characteristics and production stability were verified through regional adaptation trials conducted over three years (2020- 2022). ‘Dadrim’ exhibits a determinate growth habit, white flowers, and spherical seeds with a yellow seed coat and yellow hilum. It is a large-seeded variety with a 100-seed weight of 30.9 g. As a late-maturing variety, it reaches maturity around October 22. Despite a relatively short plant height, it features a high first pod height of 16 cm, making it advantageous for mechanical harvesting. ‘Dadrim’ is resistant to bacterial pustule and soybean mosaic virus and possesses excellent lodging resistance. Notably, ‘Dadrim’ demonstrates a high tofu yield of 283%, which is 67% points higher than ‘Daewonkong’. The resulting tofu has a soft texture, making it suitable for soft and silken tofu. It also received high preference scores for taste and texture in sensory evaluations. ‘Dadrim’ yielded 3.37 tons/ha, an 8% increase compared to ‘Daewonkong.’ This new variety is expected to increase farm income and advance the domestic tofu industry (Registration No. 10461).

South America, particularly the Southern Cone region, which includes Argentina, Brazil, Paraguay, and Uruguay, serves as a global hub for soybean production, accounting for more than 56% of global supply. However, this region experiences recurrent and severe drought risks driven by climate variability associated with the El Niño-Southern Oscillation (ENSO), resulting in significant economic losses. Consequently, biotechnology- based drought-tolerant soybean breeding has emerged as a critical national strategy across these countries. Argentina has positioned itself as a primary technology originator with the development of the HB4 soybean, the world’s first commercial drought-tolerant trait, utilizing the sunflower-derived transcription factor HaHB4. Brazil is advancing beyond single-trait approaches by developing multistacked biotech varieties that integrate drought tolerance with herbicide resistance, insect resistance, and oxidative stress mitigation. Furthermore, Paraguay and Uruguay are rapidly emerging as international hubs for field testing and commercialization, supported by streamlined regulatory frameworks and a “dual-track” strategy for both genetically modified (GM) and genome-edited (GE) crops. This review integrates molecular strategies, national regulatory systems, and commercialization trends in South America and discusses strategic implications for Korea. Despite Korea’s limited domestic experience in large-scale commercial cultivation owing to regulatory constraints, it possesses internationally competitive expertise in transcription factor engineering, CRISPR-based precision breeding, and AI-driven stress phenotyping. We propose a strategic technology export model that leverages Korea’s advanced R&D capabilities as a “technology provider” and “joint developer,” in partnership with South American countries. Such collaborations can foster a climate-resilient agricultural ecosystem and secure Korea’s position in the global biotech seed market.

Global climate change has intensified droughts and other extreme weather conditions, leading to serious declines in agricultural productivity. Genetically modified (GM) soybeans with drought tolerance have been developed to enhance crop resilience. Prior to commercialization, GM crops must undergo compositional equivalence assessments to confirm that no unintended compositional differences exist compared to their non-GM counterparts. In this study, we evaluated the nutritional and compositional equivalence of two drought-tolerant GM soybean lines (DIAT7 and DIAT15) compared to their non-GM parental line (Williams 82) and three reference cultivars (Kwangan, U13625, and U14511). Soybeans were cultivated under identical field conditions, and proximate components, amino acids, fatty acids, minerals, and antinutritional factors were analyzed using standard methods. Although several analytes exhibited statistically significant differences (p<0.05), all compositional values for DIAT7 and DIAT15 were within the natural variation ranges of the reference cultivated with GM, OECD (2012), and the AFSI Crop Composition Database (v10.1). The GM lines showed protein (36-37%), lipid (19-21%), and total dietary fiber (24-27%) contents similar to those of the reference cultivars. Amino acid profiles were dominated by glutamic acid and aspartic acid, whereas linoleic acid (42-51%) and oleic acid (29-36%) were the major fatty acids, consistent with conventional soybeans. The levels of minerals and antinutrients, including raffinose, stachyose, and phytic acid, were also comparable to the reference ranges. These findings demonstrate that the drought-tolerant GM soybeans DIAT7 and DIAT15 are compositionally and nutritionally equivalent to non-GM soybeans, supporting their substantial equivalence and providing a scientific basis for food and environmental safety evaluation.

Tofu, a widely consumed soy-based product, has seen increasing consumer demand, driven by health and dietary trends. Enhancing the processing suitability of soybeans requires analysis of the genetics associated with tofu quality traits. In this study, five key traits, namely water absorption (WA%), Brix of soymilk (°BS), soymilk yield (YM%), tofu residue (TR%), and tofu yield (YT%), were evaluated in two recombinant inbred line (RIL) populations: 81 lines of “Daepung”דSaedanbaek” and 122 lines of “Daepung”דGalchae”. Most traits exhibited normal distributions and transgressive segregation. Trait correlations revealed strong associations between WA and TR, and between YM and YT, with population-specific variation. Quantitative trait locus (QTL) mapping identified eight loci in each population linked to WA, °BS, YM, TR, and YT across multiple chromosomes. Notably, co-localized QTL were detected for WA% and TR% (chromosomes 1 and 6) and for WA%, YM%, °Brix, and TR% (chromosome 8), indicating pleiotropic regulation. Candidate genes included Glyma.06g173500, associated with β-glucan biosynthesis, and Glyma.03g132700, encoding β-glucanase, both implicated in seed coat permeability and tofu yield. These results provide novel genetic insights into seed coat properties and processing quality, and the identified QTLs and candidate genes represent valuable targets for marker-assisted selection in soybean breeding programs optimized for tofu production in Korea.

‘Ganghan’ is a high-yielding soybean (Glycine max L. Merrill) cultivar developed for improved shattering resistance and suitability for mechanized harvesting. It was bred through pedigree selection after an artificial cross between ‘Taeseon’ (female parent) and ‘Cheonga’ (male parent) in 2015. ‘Ganghan’ is a determinate type with an average main stem length of 65 cm and first pod height of 19.6 cm, which is favorable for mechanical harvesting. Compared to the control cultivar ‘Daewonkong,’ it showed stronger lodging tolerance and carried a genetic allele associated with pod shattering resistance. In disease resistance evaluations, it exhibited higher resistance than ‘Daewonkong’ to soybean mosaic virus (G6H), bacterial pustule, and black root rot. Regarding seed quality, it contained 38.8% protein, 17.6% oil, 86.1% unsaturated fatty acids, and 3,124 μg/g total isoflavones. The tofu yield was 232%, with mechanical properties and color comparable to ‘Daewonkong.’ In fermentation processing tests, ‘Ganghan’ recorded a γ-PGA content of 11.4 mg/g and amino nitrogen content of 390 mg%, indicating potential use in traditional fermented soy foods. In regional yield trials (RYT) conducted across 10 locations from 2020 to 2022, ‘Ganghan’ had an average yield of 3.58 tons/ha, 14% higher than that of ‘Daewonkong’. The adoption and expansion of ‘Ganghan’ is expected to contribute to increased domestic soybean productivity, harvest efficiency, and cultivation stability under changing climate conditions, thereby improving the domestic soybean self-sufficiency rate (Registration No. 10459).

‘Saedeul’ is a saddle-patterned seed-coated soybean cultivar developed from a cross between ‘IT224183’ and ‘Daepung (IT214696)’ in 2010. The F1 and F2 generations were grown for 2 years, and promising lines were selected using the pedigree method from F3 to F5 generations. The preliminary yield trials (PYT) and advanced yield trials (AYT) were conducted during 2016-2017, followed by regional yield trials (RYT) across seven regions during 2018-2020. ‘Saedeul’ is a determinate cultivar, having oval-shaped leaflets, purple flowers, and saddle-patterned seeds. The flowering and maturing date were August 11 and October 28, respectively. Considering its quantitative characteristics in comparison to the ‘Cheongja3ho’ cultivar, ‘Saedeul’ has a smaller seed size (27.9 g/100 seeds) and shorter plant height, but a higher first pod height. ‘Saedeul’ showed greater tolerance to both lodging and pod shattering in the RYT field and indoor tests than ‘Cheongja3ho’. It demonstrated resistance to bacterial pustule in field tests but was susceptible to soybean mosaic virus (G6H strain) in inoculation tests. The mean yield of ‘Saedeul’ in the RYT was 261 kg/10a, exceeding that of ‘Cheongja3ho’. ‘Saedeul’ is expected to replace landraces due to its resistance to lodging and bacterial pustule. (Registration number: 9456)

‘Sinbaram’ is a new cultivar developed for soy sprout production at the National Institute of Crop Science (NICS). It was developed using the line breeding method in 2010 by artificially crossing ‘Pungsannamulkong’(IT263156) with the ‘HS1371-49-2-2’ line in 2010. F₁ plants and the F₂ population were developed in 2011 and 2012, respectively, and a promising line was selected using F₃ to F₅ in the pedigree method. It was evaluated for agronomic traits, yield, and soy sprout characteristics in a preliminary (PYT) and an advanced (AYT) yield trial in 2016 and 2017, respectively. ‘Sinbaram’ has purple flowers, a lanceolate leaflet shape, grey pubescence, and small yellow seeds (10.2 g/100 seeds). The flowering and maturing dates were August 4 and October 9, which were 2 and 5 days earlier than ‘Pungsannamulkong.’ Plant height, first pod height, number of nods, number of branches, and number of pods were 46 cm, 10 cm, 14, 3.5, and 82, respectively. The germination rate and sprout characteristics were similar to those of ‘Pungsannamulkong’, and the yield was 83% higher in the sprout test. In the yield test, the yield was 3.58 tons/ha in the 2-year yield trial, which was 1% higher than that of ‘Pungsangnamulkong,’ and 2.71 tons/ha in the 3-year regional yield trial, 8% lower than that of ‘Pungsannamulkong’, with an average of 2.71 tons/ha in the four regions. In addition, the overall score of 6.7 in the processor survey was higher than 6.0 for ‘Pungsannamulkong.’ Therefore, the ‘Sinbaram’ cultivar is expected to be preferred because it has good sprout characteristics. (Registration number: 9460)

Soybean is one of the most important crops because of its high protein and oil content. Previous studies have refined protoplast isolation methods for soybeans to enhance transfection efficiency. However, these methods have limitations due to the inconsistent number of viable protoplasts for various applications. In this study, we propose an optimized protoplast isolation method to overcome this challenge. Hypocotyls grown in the dark were selected to ensure rapid growth and a steady supply of plant materials. The hypocotyls were cut to 1–2 cm in length and halved longitudinally to achieve consistent protoplast yields. Our new hypocotyl cutting method demonstrated 1.5 times improved protoplast yield and improved protoplast viability compared to that of previous methods. The isolated protoplasts were purified using the sucrose density gradient purification method to remove residues while stacking viable protoplasts. Fluorescein diacetate (FDA) staining was performed to determine the proportion of healthy protoplasts throughout the process. Consequently, we propose a new protoplast isolation protocol that ensures a higher yield, better viability, and healthier conditions. This enhancement is expected to improve the efficiency of soybean transfection.

The soybean cultivar, ‘Jangpung’, is adaptable for mechanized harvest with fewer branches and a higher first pod height. ‘Jangpung’ was developed through a pedigree method involving a cross between ‘Shingi’ and ‘SS03102-B-B-3S-21-4’ cultivars from 2010-2021. The promising line, ‘YS2243-B-B-35-1-1-1’, was selected and designated as ‘Milyang361’, whereafter it was tested in regional yield trials (RYT) for three years from 2019-2021. Its performance and stability were approved after the RYT and thereafter released as ‘Jangpung’. It has a determinate growth habit, purple flowers, grey pubescence, yellow seed coat, yellow hilum, spherical seed shape, and large seeds (28.2 g/100 seeds). ‘Jangpung’ is a late-maturing cultivar; its flowering and maturing dates were 9 August and 22 October, respectively. ‘Jangpung’ exhibited resistance to bacterial pustule and soybean mosaic virus, as well as tolerance to lodging and shattering resistance, as confirmed through genetic validation using the marker, qPDH-KS. Considering its higher first pod height, lodging and shattering tolerance, and disease resistance, the soybean cultivar, ‘Jangpung’, might assist soybean producers in achieving high adaptability for mechanization and paddy field cultivation (Registration number: 9972).

‘Seum’ is a black-seed coated soybean cultivar developed from crossing ‘IT21785’ and ‘Wonkwang (IT218557)’ in 2010. F₁ and F₂ populations were grown for 2 years and promising lines were selected by pedigree method from F₃ to F₅. The preliminary yield trial (PYT) and advanced yield trial (AYT) were conducted from 2016 to 2017, and regional yield trial (RYT) in 7 regions was conducted from 2018 to 2020. ‘Seum’ is determinate, has a lanceolate leaflet shape, purple flowers, green cotyledons, and black spherical seeds. Flowering and maturing dates were Aug. 4 and Oct. 21, respectively. ‘Seum’ has small seed size (11.4 g/100-seed) and shorter plant height than that of ‘Socheongja’. ‘Seum’ was more tolerant to lodging and pod shattering in regional field and indoor trials than that of ‘Socheongja’. ‘Seum’ was resistant to bacterial pustule during field tests and to soybean mosaic virus (G6H strain) during inoculation tests. The mean yield of ‘Seum’ in RYT was 292 kg/10a which was higher than that of ‘Socheongja’. ‘Seum’ is expected to rapidly replace the elite variety ‘Socheongja’ based on its lodging tolerance and high yield potential (Registration No. 9449).

‘Cheongja5’ is a black seed coat soybean cultivar developed from crossing ‘Milyang181’ and ‘YS1886 (Cheongdu1/Tanbaguro)’ in 2007. Promising lines were selected using the pedigree method from F₃ to F₅. The preliminary and advanced yield trials were conducted in 2013 and 2014, respectively. Regional yield trials (RYT) were conducted in seven regions from 2015 to 2017. ‘Cheongja5’ has a determinate growth habit, oval leaflet shape, brown pubescence, and white flowers. The seed of ‘Cheongja5’ has a black seed coat color with green cotyledon. Flowering and maturing dates were Aug. 3 and Oct. 24, respectively. Regarding the quantitative characteristics, ‘Cheongja5’ has large seed size (37.0 g/100-seed weight) and more pods than ‘Cheongja3’. ‘Cheongja5’ was tolerant to pod shattering in field and indoor RYT tests. ‘Cheongja5’ was resistant to bacterial pustule in the field and soybean mosaic virus (strains G6H and G7H) in the inoculation test. Although its seed quality-related characteristics were almost similar to those of ‘Cheongja3’, it contained more anthocyanin which is a main functional component of black soybean. The mean yield of ‘Cheongja5’ in the RYTs was 343 kg/10 a which was 30% higher than that of ‘Cheongja3’. ‘Cheongja5’ is expected to be widely cultivated as a material for making soy-food that uses black soybean because of its large seed size and high yield potential (Registration No. 7687).

A black soybean cultivar ‘Gyeongheukcheong’ was developed by Gyeongsangbuk-do Agricultural Research and Extension Services. ‘Gyeongheukcheong’ was selected from a cross between ‘RCS640’ and ‘Geomjeongsaeol’ in 2011. The cultivar was evaluated in multiple performance and yield trials in seven locations from 2017 to 2019. ‘Gyeongheukcheong’ has a gray pubescence, light brown pod, and dark green cotyledon, whereas ‘Cheongja 3’ has a brown pubescence, brown pod, and light green cotyledon. The seed weight and maturity of ‘Gyeongheukcheong’ was similar to that of ‘Chungja 3’. ‘Gyeongheukcheong’ was resistant to soybean mosaic virus (strain G6H), moderately resistant to bacterial pustule (caused by Xanthomonas axonopodis pv. glycines), and resistant to root rot. Total chlorophyll content (sum of chlorophyll a and b) in the green cotyledon of ‘Gyeongheukcheong’ was 48.0 μg/g, which was higher than that of ‘Cheongja 3’ (30.1 μg/g). The regional yield trial showed that ‘Gyeongheukcheong’ had a similar or significantly higher average yield than ‘Chungja 3’ in locations with single (similar) and double (19% higher) cropping systems, respectively. ‘Gyeongheukcheong’ represents a consumer-friendly black soybean with dark green cotyledons and high yield potential (Registration No. 9065).

A black soybean cultivar, “Saebaram” with green cotyledons, was developed and released by the Gyeongsangbuk-do Agricultural Research and Extension Services (GBARS) in 2019. It was developed from a single cross between “Seonheuk” and “RCS640” in 2011. The preliminary yield trial and advanced yield trial were conducted at GBARS from 2015 to 2016. The regional yield trial (RYT) was conducted in seven locations from 2017 to 2019 in Korea. “Saebaram” had purple flowers, grey pubescence, light brown pods, a black seed coat, an ellipse seed shape, and a large seed size (42.8 g/100 seeds). The seed size was significantly larger than that of the check cultivar “Cheongja 3” (36.2 g/100 seeds). Moreover, it was moderately resistant to bacterial pustule (caused by Xanthomonas axonopodis pv. glycines) and soybean mosaic virus (strain G6H). “Saebaram” had dark green cotyledons, whereas “Cheongja 3” had light green cotyledons. The total chlorophyll contents (chlorophyll a and chlorophyll b) in the green cotyledons of “Saebaram” and “Cheongja 3” were 76.1 μg/g and 30.1 μg/g, respectively. Furthermore, the RYT showed that “Saebaram” had 287 kg/10a, which was 10% higher than that of “Cheongja 3” (261 kg/10a). This black soybean cultivar with improved yield, large-size seeds, and dark green cotyledons is expected to have a high commercial value for Korean farmers (Registration No. 9155).

A soybean cultivar, “Seonyu2ho” for double cropping using soy-paste and tofu was developed in 2011 using the pedigree method by crossing “Milyang235ho” and “Jungmo3004ho.” A promising line, YS2441-B-2S-11-3, was selected and named as “Milyang334.” It demonstrated prominent early maturing, shattering resistance, and high yield in regional yield trials (RYTs) from 2017 to 2019, and was released by the name “Seonyu2ho.” The cultivar showed a determinate growth habit, white flowers, grey pubescence, yellow seed coat, yellow hilum, flat-spherical seed shape, and large seed size (27.9 g per 100 seeds). “Seonyu2ho” matured on October 5 (112-growing day cycle) in RYT and was suitable for double cropping with winter crops, such as wheat, barley, and onion. It was resistant to bacterial pustule and soybean mosaic virus and tolerant to lodging in fields. Particularly, “Seonyu2ho” showed a high yield (3.34 ton/ha) and shattering resistance, even if the previously developed early matured cultivars exhibited low yield and easy shattering. Overall, “Seonyu2ho” can contribute to stable soybean production in double cropping.

Sybeans have been grown by plant breeding for decades. As soybeans have very limited genetic variation, it is difficult for soybean breeders to find new genetic resources for abiotic stressors. Recently, soybeans have been exposed to flooding stress from intensive summer rainfall owing to climate change. Glycine soja, a wild soybean, is known to have greater genetic variation and greater resistance to a variety of biotic and abiotic stresses than ordinary soybeans. In this study, high-throughput transcriptome analysis was performed using flood-treated Glycine soja. Differentially expressed genes (DEGs) were analyzed using reads mapped to reference sequences, and gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed using selected DEGs. In addition, RT-qPCR analysis was performed to further analyze the expression of specific candidate genes. Several novel genes that could explain various mechanisms related to water stress were identified as related transcripts and adaptation mechanisms through cell wall expansion, alcoholic fermentation under anaerobic conditions, and structural changes. In addition, most of the isoflavonoid daidzein pathway genes exhibited upregulated expression under flooding stress. Interestingly, expression of the DIR (dirigent protein 1-like) gene, which is known to decrease in response to flooding stress in soybeans (Glycine max), was upregulated in Glycine soja. The expression of DIR revealed that DIR may play a key role in conferring flooding stress resistance in Glycine soja. This study provides useful information regarding the genes and comprehensive adaptation mechanisms related to flooding stress tolerance that can be utilized for cultivated soybeans through the Korean wild soybean.

Bacterial pustule is a major bacterial disease in most soybean-growing regions of Korea, resulting in soybean yield reductions of up to 60%. In this study, we aimed to understand the differences in disease severity caused by three strains of Xanthomonas citri pv. glycines, including two newly differentiated strains (K29 and K100) and the conventional representative strain, 8ra. Seventeen major soybean cultivars and 14 breeding lines were inoculated and compared for their reactions to the three strains of Xcg. The two new strains caused higher levels of disease severity, resulting in a greater number of susceptible cultivars. The landrace PI 547711, like Williams 82, was highly resistant to all Xcg strains; however, the other six cultivars that were resistant to 8ra, including Daepung2, were susceptible to the new strains (K29 and K100). In particular, the most widely grown cultivars, Daewon and Daepung2, were highly susceptible to K100. All of the breeding lines except two were also vulnerable to the new strains, K100 and K29. Of the breeding lines, SS05004-1-1-4-2-3-4 and SS05022-5-4-2-4-4-4 were resistant to the three Xcg strains, at similar levels to that of Williams 82. The breeding lines and cultivars evaluated in this study may be used to develop breeding materials resistant to new Xcg strains in the future. In addition, establishment of an improved disease evaluation system for bacterial pustule, by using multiple representative strains, is strongly recommended for breeding programs, to increase the efficiency and accuracy of selection for resistance as the pathogenic diversity of X. citri pv. glycines changes.

Soybean [Glycine max (L.) Merr.] is an excellent source of protein, oil, carbohydrates, and many other bioactive ingredients. However, its raw mature seeds also contain several antinutritional components. The newly developed soybean cultivar ‘Hayoung’ has large yellow seeds and a low stachyose content, and is free of lipoxygenase, Kunitz trypsin inhibitor (KTI), and 7S α’-subunit proteins. ‘Hayoung’ was selected from the population derived from a cross between the intermediate parent (F4-4) and the breeding line (15G1). It has purple flowers, tawny pubescence, a determinate growth habit, and light-yellow pods at maturity. The seed of the cultivar has a yellow hilum and yellow seed coat color. The dry weight seed protein and oil content were 37.9 and 16.0%, respectively. The stachyose content was 3.1 g/kg, which was much lower than 12.7 g/kg of the check cultivar, ‘Daewon’. ‘Hayoung’ has shown resistance to soybean necrosis, soybean mosaic virus, Cercospora leaf spot and blight, black root rot, pod and stem blight, and bacterial pustule. ‘Hayoung’ matured on 22 October with a plant height of 56 cm and a 100-seed weight of 32.3 g. The average yield of the cultivar was 3.12 (Ton/ha), based on regional yield trials in 2018 at four locations. ‘Hayoung’ has been registered as a soybean cultivar (registration number: 8625, registration date: June 08, 2021) by the Korea Seed & Variety Service, Republic of Korea.

Tofu is produced by mixing condensed soymilk with a coagulant. It has a low calorie and high protein and contains various important vitamins and minerals; therefore, consumption of tofu as a healthy and dietetic food has increased worldwide. For systematic application in breeding programs to increase tofu yield, evaluation of tofu characteristics is essential. To test the various characteristics of tofu, typically, a considerable amount of seeds (approximately 100 g, is required. Here, we propose a simple tofu quality test method requiring a small amount of seeds (15 g), which is 75% less than the amount needed for conventional testing. Tofu was manufactured using 20 soybean varieties with a conventional method (i.e., a tofu making machine, TM) and four simple methods: natural filtering (NF), weight pressure (WP), hand pressure (HP), and rotation machine (RM). The correlation between the five methods was assessed with respect to each tofu characteristic, and the HP and RM methods were statistically similar to the conventional methods, whereas the other methods showed differences. Regarding tofu yield, the HP and RM methods showed significantly higher correlation coefficients of 0.79 and 0.78, respectively, and the coefficient of variation between replications was also low. Therefore, the HP and RM methods were the best to easily characterize the tofu yield using a small amount of seeds. Considering the efficiency of the test, the RM method appears to be more effective than the HP method for testing multiple lines. These results will be used for the identification of quantitative trait locus/genes related to tofu quality and marker-assisted selection of breeding new soybean varieties.

In Korea, black soybeans are traditionally consumed after cooking with rice to supplement protein and oil which are lacking in rice. Seed cooking quality including seed traits after cooking with rice, which is important for consumers, were so far not comprehensively considered during the process of breeding. In this study, we first evaluated seed quality after cooking with rice, we tested the correlation between seed cooking quality and seed water absorption ratio, and we attempted to identify the Quantitative trait locus(QTL)/gene using two recombinant inbred line (RIL) populations, i.e., Daepung × Socheong2 and Daepung × Ilpumgeomjeong. Based on phenotype and correlation analyses, the main factors affecting the hardness of soybeans cooked with rice may differ between RIL population. In the Daepung × Socheong2 RIL population, one QTL associated with seed hardness after cooking with rice was identified on chromosome 11, and Glyma.11g049600, encoding peroxidase, is proposed as a candidate gene. In the Daepung × Ilpumgeomjeong RIL population, two QTLs associated with seed hardness after cooking with rice were identified on chromosomes 7 and 19, one QTL related to seed water absorption on chromosome 3, and Glyma.19g092600 encoding pectin methylesterase inhibitor are proposed as candidate genes. This is the first study on soybean cooking quality after cooking with rice, and the locations of four related QTLs were identified. The results will be of use for future development of high-quality black soybean varieties with high consumer preference using molecular breeding methods.

In this study, composition and agronomic traits, including yield-related traits, were investigated and compared among 35 Korean landrace germplasm for two years (2019 and 2020). The contents of 12 isoflavones were measured using high-performance liquid chromatography, and agronomic trait data were collected according to the Rural Development Administration criteria. Comparing isoflavone composition between the two years, all isoflavones, except glycitein, were generally higher in 2019. The values of yield-related and major agronomic traits decreased in most accessions in 2020. ANOVA showed highly significant differences (p<0.001) in genotypes, years, and genotype-by-year interaction for all isoflavones, the number of pods per plant, and 100-seed weight. The number of seeds per pod, days to flowering, and days to maturity also showed significant differences among genotypes, as well as between the two years. Correlation analysis revealed that daidzin and genistin were positively correlated with their malonylated form. Malonyl daidzin was also positively correlated with malonyl genistin levels. The accessions with the least variation in the total isoflavone content were IT 153844 (907.5 µg/g, 898.6 µg/g) and IT 252252 (663.2 µg/g, 636.4 µg/g). Some of the evaluated landraces will be a promising genetic source for developing soybean varieties with high levels of environmental stability in isoflavone content and agronomic traits.

‘Cheongmiin’ is a green seed-coated soybean cultivar developed from a cross between ‘Cheongjakong’ and ‘Daemang’ in 2002. The F₁ and F₂ populations were grown for 2 years, and promising lines were selected based on the pedigree method from generations F₃ to F₅. Preliminary and advanced yield trials were conducted from 2009 to 2010, and regional yield trials (RYTs) were conducted in eight regions from 2011 to 2013. ‘Cheongmiin’ is a determinate soybean with white flowers, green cotyledons, and spherical green seeds. The average flowering and maturing dates of ‘Cheongmiin’ were August 1^st and October 22^nd, respectively. In terms of quantitative characteristics, ‘Cheongmiin’ has a larger seed size (34.3 g/100-seed weight) than that of ‘Cheongdu1ho’ (24.5 g/100-seed weight), and has also been shown to be tolerant to lodging and pod shattering in the field in RYTs and oven drying tests, respectively. Furthermore, ‘Cheongmiin’ has been found to be resistant to bacterial pustules in the field and soybean mosaic viruses (G5H and G6H strains) in inoculation tests. The mean yield of ‘Cheongmiin’ in the RYTs was 272 kg/10 a, which was 4% higher than that of ‘Cheongdu1ho’. Given its large seed size and seed coat color, ‘Cheongmiin’ is expected to be highly useful for cooking with rice and for the preparation of rice cakes (Registration No. 7688).

Soybean (Glycine max (L.) Merr.) is one of the most important crops with economic value as a source of protein and vegetable oil for human food and animal feed. In recent years, rapidly developed genome editing techniques have shown widespread application prospects for gene function studies and for improving important agronomic traits in many crops. Therefore, it is important to establish a highly efficient method for protoplast isolation and transient expression systems in soybeans. In this study, we established an efficient method for protoplast isolation and its application to transient gene expression in Korean soybean cultivars. The protoplasts were isolated from leaves, epicotyls, hypocotyls, cotyledons, and etiolated hypocotyls using various combinations of enzyme mixtures. We found that high-quality and large amounts of protoplasts were isolated from the etiolated hypocotyls when incubated for 8 h under conditions of 0.5% cellulase, 0.5% pectinase, and 1% viscozyme. In addition, we observed a high transfection efficiency of green fluorescent protein using etiolated hypocotyl protoplasts. Taken together, our protoplast isolation and transfection method is highly efficient and can be used for gene function and molecular analysis to better understand the biological and physiological processes in soybean.

Understanding plant morphological and seed characteristics is an essential step for the utilization of genetic resources to improve targeted traits in soybean breeding programs. The purpose of this study was to evaluate the agronomic traits and seed pigments of 469 black soybean germplasms with green cotyledons to identify useful resources using multivariate analyses, correlation, principal component analysis (PCA), and cluster analyses. The results showed that the range of flowering days from planting were 37.7-71.5 days, harvesting days from planting were 112.3-153.0 days, plant height was 49.6-151.6 cm, and 100-seed weight was 9.1-49.3 g. According to the correlation analyses with agronomic traits, flowering and harvesting days were positively correlated with the plant height, number of nodes, and number of branches. Additionally, it was found that the chlorophyll a and total chlorophyll content had the greatest effect on the green color of the cotyledon. Based on the PCA, 13 quantitative traits were compressed into three components. The first three principal components accounted for 82.5% of the total variance. In this study, black soybean germplasms with green cotyledons were divided into four clusters by the K-means cluster analysis (non-hierarchical procedure), based on the PCA. The cluster analysis showed that chlorophyll a and plant height had a significant effect on the clustering of the black soybean germplasms used in this study. This study provides opportunities to easily select useful genetic resources for the development of new black soybean cultivars.

A black soybean cultivar called ‘Noksim’ was developed using pedigree selection by crossing ‘Ilpumgeomjeong’ (SLSB87-3 × YS558) and ‘PI547426’. A p reliminary y ield t rial (PYT), advanced y ield t rial (AYT), and regional y ield t rial (RYT) were conducted in t hree regions. ‘Noksim’ has a determinate growth habit, purple flowers, and spherical seeds. In the regional yield trial, the flowering and maturity dates of ‘Noksim’ were August 4 and October 13, respectively, and its 100-seed weight was 26.5 g, which was lower than that of ‘Chungja 3’ (36.5 g). Additionally, ‘Noksim’ showed resistance to lodging, soybean mosaic virus (SMV), bacterial blight, and pod shattering. In terms of the seed quality, the chlorophyll content of ‘Noksim’ was 71.19%, which was higher than that of ‘Chungja 3’ (50.78%), and its total anthocy anin c ontent w as 2 5.17 m g/100g, w hich w as t hree t imes more than t hat of ‘Chungja 3’. The mean y ield o f ‘Noksim’ i n RYT was 2.35 ton/ha, which was 18% greater than that of ‘Chungja 3’. ‘Noksim’ is suitable for cooking with rice and soy products such as soymilk because of its high brix degree (35 Brix) after cooking with rice, as well as its soymilk yield (71.2%). Overall, ‘Noksim’ has dark green cotyledons with a black seed coat that is preferred by consumers, and its early maturity with pod shattering resistance results in an increased seed yield. (Registration No. 7734).

A yellow soybean cultivar called ‘Hipro’ was developed using the single seed descent (SSD) method by crossing ‘Saedanbaek’ (SS92414 ×MD87L) and ‘Daepung’ (Baekwon × Sinpaldal2). A preliminary yield trial (PYT), advanced yield trial (AYT), and regional yield trial (RYT) were conducted in three regions. ‘Hipro’ has a determinate growth habit, white flowers, and a spherical seed shape. In the regional yield trial, the flowering and maturity dates of ‘Hipro’ were August 4 and October 17, respectively, and the 100-seed weight was 22.2 g, which was lower than that of Daewon (26 g). Additionally, ‘Hipro’ showed resistance to lodging, soybean mosaic virus (SMV), bacterial blight, and pod shattering. The seed protein content of ‘Hipro’, which was of particular interest in this study, was 53.9%, which was higher than that of ‘Daepung’ (41.5%), and the total amino acid content without tryptophan was 43.6%, 19% higher than that of ‘Daepung’. The mean yield of ‘Hipro’ in RYT was 2.23 ton/ha, which was 91.3% of the yield of ‘Daewon’. However, ‘Hipro’ showed an 11% higher yield than Daewon in Paju. As a result of the tofu characteristic test, 'Hipro' is suitable for making soy milk and tofu due to its high solid content (12.67 Brix) and protein content (13.68%) and high yield (325%) of tofu. Overall, ‘Hipro’ had high protein content, excellent processing quality for tofu and soy milk, and strong resistance to disease and pod shattering that will greatly contribute to the consumption of soybeans in Korea. (Registration No. 7735).

‘Haewon’ is a soybean cultivar for soy-sprouts. ‘Bosug’ and ‘Somyeong’ were crossed in 2003, and promising lines were selected from F3 to F6 using the pedigree method (Pedigree: HS1450-2B-3-1-1-2-2-1). Preliminary yield (PYT) and advanced yield trials (AYT) were conducted from 2010 to 2011, and regional yield trials (RYT) were conducted in five regions (Suwon, Naju, Miryang, Dalseong, and Jeju) from 2012 to 2014. In the RYTs, ‘Haewon’ had a smaller seed weight and higher yield than the standard cultivar ‘Pungsannamulkong’, which are desirable characteristics for the soy-sprout process. The morphological characteristics of ‘Haewon’ are as follows: determinate plant type, purple flowers, gray pubescence, yellow pods, small, yellow spherical seeds (8.1 g/100-seeds), and light brown hilum. The flowering and maturity dates were July 29th and October 6th, respectively. Plant height and first pod height were 55 cm and 12 cm, respectively. The lodging tolerance was also strong compared to that of ‘Pungsannamulkong’. The germination rate, total length, hypocotyl length, thickness, and sprout yield of soybean sprouts were 97%, 19.1 cm, 8.8 cm, 2.1 mm, and 513%, respectively. The yield in adaptable regions was 337 kg/10 a, 16% higher than that of ‘Pungsannamulkong’. ‘Haewon’ can be used for soy-sprout with favorable seed size and soy-sprout characteristics, such as germination and sprout-yield. (Registration No. 6637).

‘Taecheong’ is a black soybean cultivar developed from crossing ‘YS1593(Milyang136×Tanbaguro)’ and ‘Cheongja2’ in 2005. F₁ and F₂ populations were grown for 2 years and promising lines were selected by pedigree method from F₃ to F₅. The preliminary yield trial (PYT) and advanced yield trial (AYT) were conducted from 2012 to 2013, and a regional yield trial (RYT) in seven regions was conducted from 2014 to 2016. ‘Taecheong’ is determinate, with purple flower, green cotyledon, and black spherical seed. Flowering date and maturing date were August 3 and October 20, respectively. Regarding quantitative characteristics, ‘Taecheong’ has a larger seed size (44.5 g/100-seed weight) than that of ‘Cheongja3’ (35.8 g/100-seed weight). ‘Taecheong’ was tolerant to pod shattering and lodging at the RYT field and indoor test. In addition, ‘Taecheong’ was resistant to bacterial pustule during the field test, and to soybean mosaic virus (G6H strain) during the inoculation test. Although its seed quality-related characteristics were similar to those of ‘Cheongja3’, it contained more anthocyanin in its seed-coat, which is a primary functional component of black soybean. The mean yield of ‘Taecheong’ in RYT was 240 kg/10a, which was 94% of the yield of ‘Cheongja3’. ‘Taecheong’ is expected to be used as raw material for soy products, such as for preparing soybean chocolates, because of its large seed size (Registration number: 7104).

Phytophthora root rot attributable to infection by the soil-borne oomycete Phytophthora sojae causes serious damage to susceptible soybeans grown in poorly drained soil. Management of this disease depends primarily on Rps (resistance to P. sojae) resistance genes. The
objective
of this study was to map resistance to two P. sojae isolates (40412 and 2457) in a Daepung×Socheong2 recombinant inbred line population. Of these two varieties, Socheong2 is resistant to the two isolates, whereas Daepung is susceptible. Single-marker analysis of variance and linkage analyses using a high-density genetic map identified different resistance loci for each isolate. A genomic region of 36.2~37.4 Mbp on chromosome 3 was identified as being associated with resistance to isolate 40412, explaining 18% of the phenotypic variance (PV), whereas, a 2.1~2.6-Mbp region on chromosome 18 was significantly associated with resistance to isolate 2457, accounting for approximately 26% of the PV. An additional region of 53.1~53.3 Mbp on chromosome 18 was also significantly associated with resistance to isolate 2457. All three loci coincide with genomic regions where an Rps gene or partial resistance have been mapped in previous studies. The respective locus showed significance for only one or the other of the isolates, indicating an isolate-specific interaction. From this finding, it can be inferred that isolates 40412 and 2457 are characterized by different avirulence genes, and that Socheong2 has at least two Rps genes that interact with each isolate. The finding of multiple Rps loci specific to an isolate within a single soybean genotype is a unique discovery. Socheong2 will accordingly be a useful genetic source for breeding resistance to multiple P. sojae isolates.

Recent climate changes have resulted in high temperatures, a greater frequency of flooding, and outbreaks of various plant diseases and insect pests, the latter of which has been characterized by a change in pest type from crop chewing to sap-sucking insects. To date, however, there has been limited study of plant resistance to sap-sucking insects. This study was carried out to evaluate the resistance and genetic patterns of the foxglove aphid Aulacorthum solani, a sap-sucking pest of soybean. We investigated the growth and reproduction of the foxglove aphid on five different varieties of soybean showing either susceptibility or resistance to this aphid in a non-choice test. Genetic analysis was conducted using the two F₂ populations derived from Daepung (susceptible to foxglove aphid)×IT104704 (resistant to foxglove aphid) and Daepung×IT188399 (resistant to foxglove aphid) crosses, which were evaluated for their responses to foxglove aphids. Differences in the responses of resistant and susceptible varieties were confirmed by monitoring aphid growth and reproduction. Although the two resistant germplasms (IT104704 and IT188399) have a strong antibiosis effect, they showed a slight difference with respect to aphid viability. Genetic analysis of foxglove aphid resistance showed that resistance was governed by a single dominant gene in IT104704 (3:1, p=0.11). We accordingly identified two resistant resources showing antibiosis to foxglove aphid, which is reported here for the first time, and also detected differences in genetic behavior. These results could be useful not only with respect to securing materials showing resistance to the foxglove aphid but also in the breeding of new foxglove aphid-resistant soybean cultivars.

In this study, conducted in living modified organism (LMO) isolation fields, we sought to develop environmental risk assessment procedures for identifying the potential effects on non-target above-ground insects and spiders within agroecosystems cultivated with vitamin A-enhanced transgenic soybean with tolerance to the herbicide glufosinate. To this end, we investigated insect/arachnid species diversities and population densities on vitamin A-enhanced transgenic soybean and non-GM soybean (Gwangan) grown in LMO quarantine areas of Kyungpook National University (Gunwi) and the National Institute of Agricultural Sciences (Jeonju). In total, 93,419 individual insects and arachnids, representing 65 families in 12 orders, were captured during the study. In Gunwi, totals of 17,110 and 17,627 individual insects and arachnids were collected from vitamin A-enhanced transgenic soybean and Gwangan, respectively, whereas in Jeonju, totals of 28,621 and 30,061 individuals were collected from vitamin A-enhanced transgenic soybean and Gwangan, respectively. Although we detected no significant differences among the population densities of insect pests, natural enemies, and other insects on vitamin A-enhanced transgenic soybean and Gwangan grown within the same field, the population densities of these insects were found to be higher in Jeonju than those in Gunwi. Throughout the study, analysis of variance indicated no significant differences (p<0.05) in insect/arachnid populations, and multivariate analysis indicated that the abundance and diversity of plant-dwelling insects were similar within the same fields.