• Journal of Plant Biology
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• v.37 no.3
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• pp.333-341
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• 1994

Effective plant regeneration from immature cotyledons of soybean [Glycine max (L.) Merr.] cultivars was achieved via somatic embryogenesis. Somatic embryogenesis was performed with the cotyledons of immature embryos 14-20 d after flowering. Immature cotyledons of cv. Whangkeum were placed abaxial or adaxial side down on modified MS medium containing 20mg/L 2,4-D. The greatest number of somatic embryos, 1.2 per cotyledon, was produced from those of 4.0-4.9 mm in length which had been placed abaxial side down. Among cvs. Pecking, Whangkeum and Baekwoon, Pecking had the highest embryo induction efficiency with 4.3 somatic embryos per cotyledon in 20mg/L 2,4-D treatment and with 1.0 embryo per cotyledon in 8mg/L NAA treatment. Germinable globular somatic embryos were induced with the highest efficiency, 27.6%, in 20mg/L 2,4-D and were proliferated efficiently on liquid medium containing 10mg/L 2,4-D. The globular somatic embryos developed into germinable mature somatic embryos on medium containing 10 $\mu$M CoCl2, 9% sucrose, and 0.5% activated charcoal. These mature somatic embryos germinated on hormone-free mediu. After transfer to the soil, regenerated plants with seeds were obtained.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.157-162
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• 2008

A total of 2,765 accessions were used as the initial set having both seed coat color and 100-seed weight data. As a result of molecular profiling using six SSR markers followed by stratification based on their usages, 335 accessions(12.1%) were selected by clustering based on UPGMA. Since 75 out of 335 accessions were mixed in phenotypic traits as a result of characterization, 260 accessions were finally set as a core set. This core set revealed nearly the same diversity compared with the other results on morphological traits of Korean soybean landraces. In total, 115 alleles(19.2 alleles per locus) were detected in the initial set and 79 alleles(13.2 alleles per locus) were detected in the core set. All 30 major alleles were present in the initial set and in the core set as well. In allele coverage, the core set was 71.4% of the initial set. These comparisons of number of alleles, gene diversity and coverage indicated that the core set represented the entire set well.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.81-86
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• 1999

The factors affecting thermostability and reactivation of peroxidase from soybean sprouts(Glycine max L.) were investigated. The enzyme was the most stable at pH 7.0 and below 60oC. Thermostability of the enzyme was reduced by addition of sodium chloride and saccharides. The partially inactivated enzyme by heat treatment at 75oC for 10 min was reactivated up to 211.5% at the optimal reactivation condition. The optimal pH and temperature for reactivation of the enzyme were pH 9.0 and 40oC, respectively. The reactivation was completely inhibited by addition of sulfhydryl reagent such as L cysteine.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.83-90
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• 2008

Two hundred and sixty Korean soybean landrace accessions were analyzed for polymorphism at 92 simple sequence repeat(SSR) loci. The 995 identified alleles served as raw data for estimating genetic diversity and population structure. The number of alleles at a locus ranged from three to 27 with a mean of 10.4 alleles per locus. $F_{ST}$ values estimated by analysis of molecular variance(AMOVA) using SSR data set were 0.018, 0.027, and 0.016 for usage, collection site and maturity groups, respectively, indicating little genetic differentiation. The model-based clustering analysis placed the accessions into three clusters(K=3) with 0.0503 of $F_{ST}$, indicating moderate genetic differentiation. Duncan's Multiple Range Test at K = 3 on the basis of 18 quantitative traits revealed that one cluster was mainly differentiated from the other two clusters by seed related traits and the other two clusters were differentiated from each other by biochemical traits. Genetic structure of Korean soybean landraces was differentiated by model-based clustering and supported by their phenotypic traits in part. This preliminary study could be the first step towards more efficient germplasm management and utilization of soybean landraces and helpful in association studies between genotypic and phenotypic traits in Korean soybean landraces.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.146-146
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• 2017

The pod shattering or dehiscence is essential for the propagation of pod-bearing plant species in the wild, but it causes significant yield losses during harvest of domesticated crop plants. Identifying novel molecular makers, which are linked to seed-shattering genes, is needed to employ the molecular marker-assisted selection for efficiently developing shattering-resistant soybean varieties. In this study, a genetic linkage map was constructed using 115 recombinant inbred lines (RILs) developed from crosses between the pod shattering susceptible variety, Keunol, and resistant variety, Sinpaldal. A 180 K Axiom(R) SoyaSNPs data and pod shattering data from two environments in 2001 and 2015 were used to identify quantitative trait loci (QTL) for pod shattering. A major QTL was identified between two flanking single nucleotide polymorphism (SNP) markers, AX-90320801 and AX-90306327 on chromosome 16 with 1.3 cM interval, 857 kb of physical range. In sequence, genotype distribution analysis was conducted using extreme phenotype RILs. This could narrow down the QTL down to 153 kb on the physical map and was designated as qPDH1-KS with 6 annotated gene models. All exons within qPDH1-KS were sequenced and the 6 polymorphic SNPs affecting the amino acid sequence were identified. To develop universally available molecular markers, 38 Korean soybean cultivars were investigated by the association study using the 6 identified SNPs. Only two SNPswere strongly associated with the pod shattering. These two identified SNPs will help to identify the pod shattering responsible gene and to develop pod shattering-resistant soybean plants using marker-assisted selection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.310-317
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• 2006

This study was conducted to investigate the influence of drought stress during the pod developing and seed filling stage on source-sink relationships of soybean (Glycine max). Drought treatments were imposed by withholding water at the full-pod stage, 19 days after flowering, and then limited watering was relieved at 15 days after the initiation of drought treatment. Soybean seed yield was reduced by 39% mainly due to decreased pod number under drought stress, but the 100-seed weight was relatively less reduced. In spite of the 15-day drought during the full-pod stage, soybean produced good seeds showing similar l00-seed weight, protein, starch and soluble sugar content to those from the well-watered. Although drought during the full-pod stage caused source limitations; i.e. accelerated leaf senescence and reduced leaf soluble sugars, it did not cause limitations of other source characteristics such as SGR and leaf starch level. This is because the reduction in size of sinks, such as pod and seed abortions compensated for source limitations, resulting in balanced source-sink as expressed by LAR and the ratio of leaf area to seed dry weight. Drought stress during the pod developing and seed filling stage did not disrupt the source-sink balance

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.265-267
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• 2005

Study on effectiveness of Bradyrhizobium japonicum on soybean [Glycine max (L.) Merr.], local cultivar 'Sathiya' were carried out in the garden soil of Trib-huvan University. Different parameters like nodulation, chlorophyll content in fresh leaves and growth of plant in inoculated and uninoculated plant was studied. Pot experiment was conducted in the green house to evaluate the effectiveness of B. japonicum on soybean. It was observed that B. japonicum inoculation increased the number of nodules, shoot length of plant and total chlorophyll content in fresh leaves of soybean plant. However, root length was decreased in all inoculated plants.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.109-115
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• 1990

This study was carried out to investigate the effect of L-cysteine and sodium sulfite on heat inactivation of soybean trypsin inhibitor(STI) and to determine cultivar difference in the inhibitory activity of STI. Effect of L-cysteine and sodium sulfite at different concentrations, pH's, and lengths of treatment on inactivation of STI were studied. The inactivation of STI was spectrophotometrically determined by measuring the rate of production of p-nitroaniline from synthetic substrate, N-benzoyl-DL-arginine-p-nitroanilide. Addition of L-cysteine and sodium sulfite increased magnitude of heat inactivation and greatly inhibited the re-activation of STI. There was no difference STI inactivation in among soybean cultivars employed. The trypsin inhibitory activity of STI of the soybean cultivars ranged from 64.7 to 86.4 TIU(trypsin inhibitor unit) per gram soyflour and the decreasing order of the TIU was Jangback>Hill>Jangyeab, Kwangkyo> Danyeab>Dangkyung>Paldal, Saeal, Duckyu>Hwangkeum. Inhibitory activity of STI was correlated with cysteine $content(r=0.6568^*)$ and with $digestivility(r=-0.7695^{**})$, but there was no correlation between the protein content and the inhibitory activity of STI.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.580-583
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• 2007

Little is known about the genetic variability in lutein content for soybeans (Glycine max L.) cultivated in Korea. Therefore, the objective of this study was to screen high quality soybean cultivars for lutein content. The lutein contents of 23 recommended varieties, 56 sauce varieties, 44 sprout varieties, and 40 local varieties were determined by saponification followed by reversed phase high performance liquid chromatography (HPLC). We found that IT No. 153398 and 22789, originating from sauce and local varieties, respectively, contained significantly higher amounts of lutein as compared to the other 161 samples. Moreover, relevant quantitative differences were found among the samples, which had lutein contents ranging from 83 to $402{\mu}g/100g$ in the recommended varieties, from 39 to $778{\mu}g/100g$ in the sauce varieties, from 52 to $589{\mu}g/100g$ in the sprout varieties, and from 106 to $861{\mu}g/100 g$ in the local varieties, respectively. In summary, this study provides reliable lutein data for soybean cultivars that can be used for breeding studies and the development of functional foods.

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.71-78
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• 2024

This study was in order to select soybean (Glycine max (L.) Merrill) cultivars that are suitable for cultivating in paddy fields of the southern Korea and beneficial for mechanized harvesting with combine harvesters. Five soybean cultivars were cultivated in paddy fields to survey growth characteristics and seed yield, and evaluate the nutritional value of seed. Plant height was longer than 55 cm for 'Cheongja-3ho', 'Daewon' and 'Seonpung'. First pod height was higher than 12 cm for 'Daewon', 'Seonpung', and 'Seonyu-2ho'. Seed yields were 280 kg/10a or more for 'Daechan', 'Seonpung' and 'Daewon'. The protein content of 'Daechan' were 40.7%, which was significantly higher than those of the other cultivars, and isoflavone content was higher than 200 ㎍·g^-1 for 'Seonpung', 'Cheongja-3ho', 'Daechan', and 'Daewon'. These results suggest that 'Daechan', 'Seonpung', 'Daewon' could be suitable for cultivating in paddy fields, and 'Daewon' and 'Seonpung' could be more beneficial for mechanized harvesting with combine harvesters. Furthermore, 'Daechan' and 'Seonpung' have not only high seed yields, but also high protein and isoflavone contents, suggesting that they could be used for production of various food products.