• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.483-489
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• 2012

Preference of stink bugs to various leguminous seeds was evaluated by using VTS (Video Tracking System) in laboratory. Major soybean stink bugs such as bean bug, Riptortus pedestris (Fabricius), one-banded stink bug, Piezodorus hybneri (Gmelin), eastern green stink bug, Nezara antennata (Scott), and sole bug, Dolycoris baccarum (L.) were significantly most attracted to Cheongjakong, a soybean variety, baited fish-net trap, followed by soybean varieties Ilpumgeomjeongkong and Taekwangkong, a peanut variety Daekwangdangkong, a kidney bean variety Gangnangkong, and a adzuki bean variety Jungwonpat, respectively in a soybean field. VTS observation in laboratory showed that R. pedestris and D. baccarum had significantly higher frequency of visit on Cheongjakong, followed by Ilpumgeomjeongkong. However, P. hybneri, N. antennata and Halyomorpha halys (Stal) had significantly higher number of visits on Cheongjakong, Seonnogkong and Jinpumkong, followed by Ilpumgeomjeongkong. The sojourned time of stink bugs, however, was significantly longer on Cheongjakong regardless of species of the bugs. Accordingly, Cheongjakong was evaluated as the most preferred soybean seed by fish-net trap and VTS. Thus, VTS is found to be an effective means to evaluate the food preference of stink bugs.

• Korean Journal of Breeding Science
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• v.51 no.4
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• pp.475-481
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• 2019

The soybean cultivar 'Neulchan' was developed for production of soy-paste and tofu. SS91501-9-1-1 and SS96205 (F₂) were crossed in 1998, and F₃ to F₇ were selected by the pedigree method. A preliminary yield trial (PYT) and an advanced yield trial (AYT) were conducted from 2006 to 2008, and a regional yield trial (RYT) in nine regions was conducted from 2009 to 2011. In the RYT, 'Neulchan' was stable in variable environments and generated high yield. 'Neulchan' was determinate with white flower, light brown pod color, yellow spherical seed, and yellow hilum. Its flowering date and maturity date were Jul. 30 and Oct. 9, respectively. The plant height was shorter than that of 'Daewonkong' (a standard cultivar). 'Neulchan' had the same node number (14), higher first-pod height (12 cm), and lighter seed weight (21.7 g/100-seed weight) than those of 'Daewonkong' (14, 11, and 24.2 g/100-seed weight, respectively). 'Neulchan' had high resistance to bacterial pustule, and its resistance to soybean mosaic virus was similar to that of 'Daewonkong'. The yield and color of 'Neulchan' tofu were similar to those of 'Daewonkong' tofu, but the hardness was lower than that of 'Daewonkong' tofu. The soybean malt scent, fermented soybean yield, and γ-polyglutamic acid (γ-PGA) of 'Neulchan' were 3, 215%, and 24.6 mg/g, respectively. Its yield in adaptable regions was 307 kg/10a, higher than that of 'Daewonkong'. 'Neulchan' was expected to be cultivated and used widely for soy-paste and tofu production. (Registration No. 4904).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.135-166
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• 1977

Some biochemical features of varietal variation in seed protein and their implications for soybean breeding for high protein were pursued employing 86 soybean varieties of Korea, Japan, and the U.S.A. origins. Also, studied comparatively was the temporal pattern of protein components accumulation during seed development characteristic to the high protein variety. Seed protein content of the 86 soybean varieties varied 34.4 to 50.6%. Non-existence of variety having high content of both protein and oil, or high protein content with average oil content as well as high negative correlation between the content of protein and oil (r=-0.73$^{**}$) indicate strongly a great difficulty to breed high protein variety while conserving oil content. The total content of essential amino acids varied 32.82 to 36.63% and the total content of sulfur-containing amino acids varied 2.09 to 2.73% as tested for 12 varieties differing protein content from 40.0 to 50.6%. The content of methionine was positively correlated with the content of glutamic acid, which was the major amino acid (18.5%) in seed protein of soybean. In particular, the varieties Bongeui and Saikai ＃20 had high protein content as well as high content of sulfur-containing amino acids. The content of lysine was negatively correlated with that of isoleucine, but positively correlated with protein content. The content of alanine, valine or leucine was correlated positively with oil content. The seed protein of soybean was built with 12 to 16 components depending on variety as revealed on disc acrylamide gel electrophoresis. The 86 varieties were classified into 11 groups of characteristic electrophoretic pattern. The protein component of Rm=0.14(b) showed the greatest varietal variation among the components in their relative contents, and negative correlation with the content of the other components, while the protein component of Rm=0.06(a) had a significant, positive correlation with protein content. There was sequential phases of rapid decrease, slow increase and stay in the protein content during seed development. Shorter period and lower rate of decrease followed by longer period and higher rate of increase in protein content during seed development was of characteristic to high protein variety together with earlier and continuous development at higher rate of the protein component a. Considering the extremely low methionine content of the protein component a, breeding for high protein content may result in lower quality of soybean protein.n.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.353-364
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• 2020

Recently in Korea, soybean harvesting has been delayed due to rainfall during the harvesting season, resulting in a reduction in yield and seed quality. This study was conducted to analyze the changes in yield and seed quality during delayed harvest with rainfall treatment using different harvesting methods, including field harvesting and polyethylene film covering after cutting fully-matured soybean plants (PE covering after cutting), with two major Korean soybean cultivars (Glycine max L), Pungsannamulkong and Daewonkong. The shattering rate of Pungsannamulkong, which is higher than that of Daewonkong, increased up to 41.8% when the harvest was delayed for 40 days without rainfall treatment by harvesting with PE covering after cutting. The weight of 100 seeds tended to decrease slightly as harvesting was delayed. When Daewonkong was harvested using the PE covering after cutting method with rainfall treatment, the yield decreased to the lowest level with a 0.8 kg ha^-1 daily reduction rate. Pungsannamulkong showed the lowest yield when harvested using PE covering after cutting without rainfall treatment with a 3.4 kg ha^-1 daily reduction rate. The infected seed rate increased according to the harvest delay in both cultivars, and significant differences were observed according to rainfall treatment and harvesting method. The germination rate was maintained above 95% even after 40 days of delayed harvest if there was no rainfall treatment. However, with rainfall treatment, the germination rate was significantly lowered as harvesting time was delayed. In the field harvesting with rainfall treatment, the germination rate decreased to 77.2% for Daewonkong and 76.5% for Pungsannamulkong after 40 days of harvest delay. For the 100-seed weight, effects of individual treatments and interactions between treatments were not observed. In contrast, the effect of interactions between treatments on the shattering rate was significant in both cultivars, indicating that the shattering rate had the greatest impact on the yield changes during delayed harvest.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.560-566
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• 2016

Imports of genetically modified (GM) soybeans (Glycine max) for food or feed consumption in Korea have been increasing. Although the cultivation of GM soybeans has not yet been allowed in Korea, the number of field tests for GM soybeans has also been rising. This study was conducted to investigate whether herbicide tolerant GM soybean can survive and persist in uncultivated environments when they escape from transportation routes or from isolated fields. Seeds of GM and non-GM soybeans and wild soybeans (Glycine soja) were buried in 2 and 15 cm soil depths and their viability was examined after 1, 2, 6, and 10 months. GM and non-GM soybean seeds completely lost their viability within six months of burial, whereas seeds of wild soybean maintained their viability during the study period. Seeds of soybean and wild soybeans that were sown on the soil surface germinated and grew to vegetative cotyledon stage. Seedlings of GM and non-GM soybean did not compete well with weeds, including Cerastium glomeratum, Alopecurus aequalis var. amurensis, Capsella bursa-pastoris, Conyza canadensis, Stellaria aquatica, and Erigeron annuus. Also, GM soybean did not survive through winter. However, wild soybeans competed well with the weeds and became dominant in August. Herbicide tolerant GM soybean is unlikely to persist under uncultivated environments and to become weeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.123-127
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• 2000

The objective of this study was to develop a linkage map of soybean under the genetic background of Korean soybean. A set of 89 F/sub 5/ lines was developed from a cross between 'Pureunkong', which was released for soy-bean sprout, and 'Jinpumkong 2', which had no beany taste in seed due to lack of lipoxygenase 1, 2, and 3. A linkage map was constructed for this population with a set of 113 genetic markers including 7 restriction fragment length polymorphism (RFLP) markers, 79 randomly amplified polymorphic DNA (RAPD) markers, 24 simple sequence repeat(SSR) markers, and 3 morphological markers. The map defined approximately 807.4 cM of the soybean genome comprising 25 linkage groups with 98 polymorphic markers. Fifteen markers remained unlinked. Seventeen linkage groups identified here could be assigned to the respective 13 linkage groups in the USDA soybean genetic map. RFLP and SSR markers segregated at only single genetic loci. Fourteen of the 25 linkage groups contained at least one SSR marker locus. Map positions of most of the SSR loci and their linkages with RFLP markers were consistent with previous reports of the USDA soybean linkage groups. For RAPD, banding patterns of 13 decamer primers showed independent segregations at two or more marker loci for each primer. Only the segregation at op Y07 locus was expressed with codominant manner among all RAPD loci. As the soybean genetic map in our study is more updated, molecular approaches of agronomically important genes would be useful to improve Korean soybean improvement.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.286-291
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• 2002

Seedling establishment of soybean [Glycine max (L.) Merr.] is a critical factor in production system and cultural practices. The objective of this study was to identify the components of soybean seedling developments encompassing planting dates and cultivars that respond to emergence, early growth stage and dry matter accumulation. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted at Baegsan silty loam soil. Planting date was May 13, June 3, and June 24 in 2001. Sprinkler irrigation was accompanied with 30mm after seeding for three planting dates. Soybean seedlings were sampled at the growth stages from VE to V5. Days to emergence of soybean seedlings were taken 8 at May 13 and 5 at June 24 plantings. Emergence percentage was over 90 at three planting dates. May 13 planting took 33 days and June 24 planting was 25 days for reaching V5 growth stage. Cotyledon number was decreased after V2. Significant cultivar difference was found in cotyledon dry weight until V2 which differed in seed dry weights at the planting times. Leaf and total dry weights of soybean seedlings were not differed from V1 to V3 among planting dates and cultivars. Leaf water contents were generally ranged 78 to 85%. Branch was appeared from V4. Leaf/stem ratio among cultivars was similar at five growth stages and gradually increased from 2.1 at V1 to 2.8 at V5. The results based on this experiment indicated that seedling establishment of soybean was continued from VE to V3 growth stages affecting mainly by planting date and soil moisture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.423-428
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• 2004

Soybean seeds contain high amounts of isoflavones that display biological effects and isoflavone content of soybean seed can vary by year, environment, and genotype. Objective of this study was to identify quantitative trait loci that underlie isoflavone content in soybean seeds. The study involved 85 $F_2$ populations derived from Korean soybean cultivar 'Kwangkyo' and wild type soybean 'IT182305' for QTL analysis associated with isoflavone content. Isoflavone content of seeds was determined by HPLC. The genetic map of 33 linkage groups with 207 markers was constructed. The linkage map spanned 2,607.5 cM across all 33 linkage groups. The average linkage distance between pair of markers among all linkage groups was 12.6 cM in Kosambi map units. Isoflavone content in $F_2$ generations varied in a fashion that suggested a continuous, polygenic inheritance. Eleven markers (4 RAPD, 3 SSR, 4 AFLP) were significantly associated with isoflavone content. Only two markers, Satt419 and CTCGAG3 had F-tests that were significant at P<0.01 in $F_2$ generation for isoflavone content. Interval mapping using the $F_2$ data revealed only two putative QTLs for isoflavone content. The peak QTL region on linkage group 3, which was near OPAG03c, explained $14\%$ variation for isoflavone content. The peak QTL region on linkage group 5, which was located near OPN14 accounted for $35.3\%$ variation for isoflavone content. Using both Map-Maker-QTL $(LOD{\geq}2.0)$ and single-factor analysis $(P{\leq}0.05)$, one marker, CTCGAG3 in linkage group 3 was associated with QTLs for isoflavone content. This information would then be used in identification of QTLs for isoflavone content with precision

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.118-122
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• 2005

This study was carried out to obtain useful information and to select promising materials for the breeding of sprout-soybean by the analysis of seed characteristics and chemical composition of Korean local wild soybean lines. For this purpose, crude protein, crude oil contents and fatty acid composition of 70 lines analysed. The crude protein content of Korean wild soybean lines ranged from 35.6 to $47.9\%$, mean was $42.34\%$, and 13 lines showed high protein content over $45\%$. The crude oil content of those ranged from 2.8 to $18.0\%$, mean was $10.2\%$, and 2 low lines were below $2\%$. The fatty acid 16:0, 18:0, 18:1, 18:2, 18:3 ranged $11.1-44.6\%,\;3.0-11.4\%,\;11.1-30.6\%,\;12.4-59.5\%,\;and\;1.1-17.3\%$ respectively, and 2 extremely low fatty acid(18:3) lines were selected. Significant correlation between crude oil and fatty acids(16:0, 18:0, 18:2), and among every fatty acid compositions were recognized. Promising wild soybean lines were selected as genetic resources for sprout-soybean breeding and research genotypes; YWS 104 and YWS189 as the high protein, YWS 28 and YWS30 as the low-crude oil and low 18:3.

• Research in Plant Disease
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• v.7 no.2
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• pp.107-111
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• 2001

Deterioration of pod and seed quality by pod and stem blight and purple blotch is a serious problem in the production of vegetable soybean. Major inoculum sources for the causal pathogens, Phomopsis spp. and Cercospora kikuchii, are soybean straw and debris. Phomopsis spp. have been known to be either limited for hyphal growth or latent in immature soybean tissues. In this experiment, cultural practices using these ecological traits of the pathogens were applied as a control measure. In plastic mulching, seed infection was remark ably reduced by drip irrigation as compared to overhead sprinkling, but not reduced in no mulching cultivation. Control value of plastic mulching was 28.0% for pod and stem blight and 29.3% for purple blotch, which was lower than that of benomyl application. By the first week in June, 78% of overwintered soybean straw examined contained matured alpha spores in pycnidia, acting as primary inoculum. Secondary inoculum of phomopsix spp. was observed abundantly throughout from mid June to September on fallen cotyledons from current crops and subsequently was found on petiole debris. Consequently, both plastic mulching and drip irrigation were effective to some extent for controlling pod and stem blight and purple blotch without significant reduction in soybean yield, and the cultural practices in combination with field sanitation resulted in removing more the secondary inoculum.