• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.599-607
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• 2006

The experiments were carried out to develop simulation model for estimating the yield of soybean in upland and paddy field condition. Field experiments were done at National Institute of Crop Science in 2005. The evaluated soybean cultivars were Taekwangkong, Daewonkong, and Hwangkeumkong. Soybean seeds were planted by hill seeding with 3-4 seeds and row and hill spacing were $60{\times}10cm$ in upland and $60{\times}15cm$ in paddy field. Seeds were sown on row (without making ridge) and on the top of ridge in upland and paddy field, respectively. Field parameters were measured yield components ($plants/m^{2}$, pod no./plant, and 100-seed weight, seed yield and growth characteristics (stem length, leaf area at each stage, and dry weight of shoot) and after measuring they were compared the relationships with seed yield and yield components and seed yield and growth characteristics. Seed yield of soybean was affected by cultivars and planting density. Seed yield was higher in upland than paddy field due to the higher planting density in upland field. The upland soybeans generally had lower 100-seed weight than that of paddy field. Seed yield of soybean in a paddy field was greatest in Taekwangkong and followed by Daewonkong and Hwangkeumkong. The harvest index of taekwangkong and Hwanggumkong was higher in upland than paddy field, however, it was higher in paddy field than upland in Daewonkong. Seed yield was greatest in Daewonkong in both experimental fields. The greatest stem length was observed in taekwangkong and Hwanggumkong (R6) in late growth stage in paddy field. Dry weight of shoot and pod, pod number, stem length, and stem diameter were higher grown in paddy field than grown in upland. Crop growth rate (CGR) of cultivars was higher in paddy field after 8 WAS(weeks after sowing) and it was greatest at 13 WAS in Daewonkong among the cultivars. In upland field, CGR was greatest in Taekwangkong and then followed by Daewonkong and Hwanggumkong during 12 and 15 WAS. There was no significant relationships between 100-seed weight and seed yield in both experimental fields. A significant positive relationship was observed between seed number and seed yield. The correlation coefficients between leaf area and shoot dry weight were about 0.8 during the whole growth stage except 5 WAS and 4-5 WAS in paddy field and upland, respectively. This experiment was done just one year and drained paddy field condition was not satisfied drained condition successfully at 7th leaf age of soybean by the heavy rain, so we suggest that the excessive soil water reduced seed yield in paddy field and the weather condition should be considered for utilizing of these results.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.57-66
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• 2013

The purpose of this study was to investigate the effects of shifts in sowing time on the ecological responses, growth and yields of major soybean cultivars in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (latitude $35^{\circ}$ 04'N, longitude $126^{\circ}$ 54'E) for three years from 2008 to 2010. The test cultivars included Saeol-kong and Tawon-kong of the summer type, Taekwang-kong and Pungsannamul-kong, and Cheongja3 of the autumn type. Sowing took place on May 15 and 30, June 15 and 30, and July 15 of each year. Of the summer type soybean cultivars, Saeol-kong showed a smaller curtailment in days from sowing to flowering, days from flowering to maturity, and days from sowing to maturity according to sowing time postponement than Tawon-kong. Of the autumn type soybean cultivars, Taekwang-kong exhibited a lower photoperiodic response in reproductive growth period than Pungsannamul-kong and Cheongja3, both of which recorded higher level photoperiodic responses in vegetative growth stages and reproductive growth periods than other test cultivars, with the former exhibiting higher levels than the latter. Most of the test cultivars tended to decrease in stem length, node numbers of the main stem, and stem diameter according to postponed sowing time, but there were no significant differences in stem length and node numbers of the main stem of the Saeol-kong cultivar. Differences in sowing times did not affect the first setting pod node order of Saeol-kong and Tawon-kong summer type cultivars of internode lengths of all of the test cultivars. All of the test cultivars tended to show decreases in pod number per plant due to postponement of sowing time except for the Saeol-kong cultivar. The variation was more prominent in small grain cultivars such as Tawon-kong and Pungsannamul-kong with the latter autumn type cultivar showing especially large variation. Yields were the greatest for the Tawon-kong, Taekwang-kong, and Pungsannamul-kong cultivars sown on May 30 and Cheongja3 sown on May 30 and June 15. There were no significant differences in the yields of Saeol-kong for different sowing times from May 30 to July 15, with the yields lowest for the batch sown on May 15.

• Research in Plant Disease
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• v.16 no.3
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• pp.266-273
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• 2010

Bacterial pustule of soybean (Glycines max) caused by Xanthomonas axonopodis pv. glycines is one of the most prevalent bacterial diseases of soybean. This bacterium shows strong pathogenicity to the plants and distributes throughout Korea. However, no good control measures including bactericides and resistant cultivars are available to control the disease in Korea. Therefore, this study was conducted to develop chemical control method against soybean bacterial pustule. The present study was undertaken to find out the growth inhibitory effect bactericides (8 antibiotics, 2 copper compounds, quinoline, 18 agro-chemicals) on bacterial pustule pathogen. Antibiotics test showed that tetracycline and streptomycin sulfate significantly suppressed the growth of bacterial pustule pathogen. Also, application of oxolinic acid was found to be effective for pathogen inhibition. However, vancomycin, polymyxin B sulfate and copper compounds did not show the positive suppressive effect on growth of the pathogen. Among the eighteen agro-chemicals, streptomycin sulfate + oxytetracyclin (18.8 + 1.5%) WP, oxytetracycline (17%) WP and oxolinic acid (20%) WP were found to be effective for the inhibition of the pathogen in vitro. The selected 5 agro-chemicals were also applied on soybean in field and their control effects against the soybean bacterial pustule were tested. The foliar application of streptomycin sulfate + oytetracyclin WP and oxytetracycline WP on the naturally infected soybean (Taekwangkong) showed high control value (above 70%). Therefore, it is concluded that the bactericides used in this study showed strong inhibitory effect to soybean bacterial pustule and they can be recommend to farmers to control the disease.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.283-287
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• 1999

This study was carried out to select the most suitable soybean cultivars for the quality kanjang preparation. Six cultivars of soybean, Taekwangkong, Kumjungkong #1, Sinpaldalkong #2, Hwangkeumkong, Danbaegkong and Danyeobkong, were used as the raw materials for kanjang preparations. Grain type meju was prepared by the inoculation of Bacillus subtilis var. globigii seed culture on the cooked soybean of respective cultivar and cultivation at $30^{\circ}C$ for 10 days. Two month matured respective kanjang mash, which was prepared by mixing meju and 20% salt brine in the ratio of 1 : 3, was separated and the liquid portions were used as kanjang samples for this work. The highest crude protein content of 47.5% was obtained from Danbaegkong cultivar among six soybean cultivars tested. High sugar soybean cultivars were found to be Kumjungkong l and Danbaegkong and the content 15.87% and 13.33% respectively. The highest total nitrogen(TN) content of 1.18% was shown from Danbaegkong kanjang. Although the major free organic acid in kanjang was found to be succinic acid, no significant differences in free organic acid and sugars content were observed among cultivars. The highest free total amino acids(TA) and glutamic acid(GA) content in kanjang was observed to be 3365 mg% and 734.44 mg% respectively from Danbaegkong kanjang. Danbaegkong cultivar soybean which was shown to contain the highest crude protein was found to be the most suitable one for the preparation of quality kanjang with high TN, GA content and GA/TA ratio.

• Research in Plant Disease
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• v.13 no.3
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• pp.145-151
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• 2007

Xanthomonas axonopodis pv. glycines is the causal agent of bacterial pustule of soybean(Glycine max. (L.) Merr), which is one of the most prevalent bacterial diseases in Korea. In this study, Polymerase Chain Reaction (PCR) assay was applied to detect Xanthomonas axonopodis pv. glycines and to survey on seed contamination in 36 soybean cultivars of Korea. And we have to compare PCR assay with dilution-plating assay of detection and identification. We confirmed detection of pathogen from artificial infected seeds and natural Infected seeds using PCR assay. This assay gave results similar to a seed-wash dilution plating assay and proved more effective than classical methods. Results of survey on seed contamination by X. axonopodis pv. glycines from 36 cultivar seeds showed that the pathogen was detected from Pungsan-namulkong, Mallikong, Taekwangkong, Daemangkong, Ajukkarikong using PCR assay. Therefore, The PCR assay provides a sensitive, rapid tool for the specific detection of X. axonopodis pv. glycines in soybean seeds.

• Korean Journal of Organic Agriculture
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• v.14 no.2
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• pp.191-204
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• 2006

This study was conducted to identify the effect of planting date and cultivation method on soybean growth and yield in paddy field. The plant height of soybeans in single cropping(SC) was higher than those in cultivating after barley culture (CB). Considering planting date and cultivation method, plant height tend to be higher in SC with level row cultivation(LR) and in CB with high ridge cultivation(HR). In this SC method, nodule formation in LR was better than in HR, but number of nodules of cv. Hwangkeumkong was highest, regardless of planting date and cultivation method. In the progress of growth stage, leaf areas of all cultivars were distinctively increased in CB than in SC. However, dry weight of top plants and roots in SC was comparably higher than that in CB due to growing periods of the soybeans. In cultivation methods, general type of dry weight of top plants was higher in LR than in HR, however, root dry weight was via verses. Growth responses varied depending on cultivars, cultivation methods, and planting date and these factors affected to shoot root (T/R) ratio. The T/R ratios in LR and SC were higher than those in HR and CB. In R8 stage, number of pods and ripened seed varied depending on cultivars. cv. Hwaeomputkong, which showed early maturing trait, was lowest. However, both yield factors tended to be higher in HR and CB than in LR and SC. The ratios of ripened seeds percentage of cv. Hwangkeumkong and cv. Eunhakong were higher in CB than in SC. However, yields of cv. Daewonkon and cv. Taekwangkong were higher in CB than in SC.

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.143-153
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• 2016

Plant regeneration via organogenesis and somatic embryogenesis was investigated in Korean soybean cultivars including Cheongja 3, Jinpumkong 2, Taekwangkong and Uram. Cotyledon, cotyledon+hypocotyl and hypocotyl segments of 7-day-old seedlings were cultured on MS medium containing various concentration (0, 1, 2 and 4 ㎎/L) of BA and TDZ. The results showed that MS medium supplemented with BA 2.0 ㎎/L yielded the highest shoot formation ratio of 83.3%. In 4 cultivars, Taekwangkong showed the highest ratio of shoot formation. When various sizes of immature cotyledons (S: 1∼ 2 ㎜, M: 3∼5 ㎜, L: 6∼8 ㎜) were tested on MS medium containing 2,4-D 40 ㎎/L for somatic embryogenesis, the optimum size for embryogenic callus induction was 3∼5 ㎜ in length of immature cotyledons. In 4 cultivars, Taekwangkong showed the highest percentage of embryogenic callus induction. The results indicate that Taekwangkong is the best soybean cultivar for plant regeneration via organogenesis and embryogenic callus induction among the 4 cultivars.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.502-506
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• 2010

Soybean seed possesses about 15 allergenic proteins recognized by IgEs from soy-sensitive human. The allergenic impact of soybean proteins limit its extensive usage in a broad range of processed foods. Soybean protein P34 or Gly m Bd 30k of the cysteine protease family is one of the major allergen of the soybean seed. P34-null soybean, PI567476, was identified among soybean (Glycine max & Glycine soja Sieb. and Zucc) of approximately 16,226 accessions from USDA soybean germplasm screened. Also, for P34 gene (Williams 82; whole genome sequence cultivar) and P34 null gene (PI567476) comparative analysis of sequences listed in the NCBI database showed the presence of a SSLP (Simple Sequence Length Polymorphism) of 4 base pair. So, a SSLP marker was designed to reveal the polymorphism of the locus. In this study, a population of 339 $F_2$ recombinant inbred lines generated by cross between Taekwang (Glycine max) and PI567476 was used to select $F_{2:3}$ plant of a P34 null gene. The result separation rate Taekwang type, heterozygous type and PI567476 type were shown in 85: 187: 67 since single gene is concerned in as the separation rate of 1:2:1 in $X^2{_{0.05}}=5.99$, df=2. In future, selected plant will identify protein level, whether P34 null protein is equal to P34 null gene.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.390-399
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• 2010

Non-photochemical quenching (NPQ) values for utilizing them to detect osmotic tolerance in plants were examined with two different soybean cultivars, an osmotic tolerant soybean (Shinpaldalkong 2) and a control soybean (Taekwangkong). Two different stresses were applied to the cultivars as the restricted irrigations of 200 and 50 ml water $pot^{-1}\;d^{-1}$ for 5 days for a control and a drought stress, respectively, and a sodium chloride solution of 200 mmol for 6 days for a salt stress. The intact leaves of the two cultivars after treatment were used to measure chlorophyll fluorescence parameters, maximum efficiencies of photosystem II photochemistry (Fv/Fm), efficiencies of photosystem II photochemistry (${\Phi}_{PSII}$), $CO_2$ assimilation rate ($P_N$), and NPQ. Leaf water potentials of the two cultivars decreased from - 0.2 to - 0.8MPa by a drought treatment and from - 0.7 to - 1.7MPa by a salt treatment. Leaf water content of Shinpaldalkong 2 after a salt treatment was less decreased than that of Taekwangkong. $F_v/F_m$ values of both cultivars were not changed, while ${\Phi}_{PSII}$ and $P_N$ were decreased proportionally to leaf water potential decrease. The response of NPQ was occurred in Shinpaldalkong 2 under the drought and salt stresses. With Taekwangkong cultivar, only drought stress referred NPQ response. The cultivar differences on chlorophyll fluorescence parameters were found in the relationships between ${\Phi}_{PSII}$ and $P_N$, and between NPQ and ${\Phi}_{PSII}$. Although the positive relationships between ${\Phi}_{PSII}$ and $P_N$ were established on all treatments of both cultivars, the decreasing rate of ${\Phi}_{PSII}$ to $P_N$ was smaller in Shinpaldalkong 2 than Taekwangkong. The NPQ was increased according to the decrease of ${\Phi}_{PSII}$ by osmotic treatments in Shinpaldalkong 2. The complementary relationships between NPQ and ${\Phi}_{PSII}$ were well maintained at all treatments in Shinpaldalkong 2, while these relationships were lost at a salt treatment in Taekwangkong. Taken together, the results suggest that analysis of complementary relationships between ${\Phi}_{PSII}$ and NPQ could be more valuable and applicable for determining osmotic tolerance than single analysis of each parameter such as $F_v/F_m$, ${\Phi}_{PSII}$ and NPQ.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.38-46
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• 2014

The purpose of this study was to investigate the effects of sowing time on the bio-active content of major soybean cultivars in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (latitude $35^{\circ}$ 04'N, longitude $126^{\circ}$ 54'E) from 2008 to 2010. The cultivars grown in summer included Saeol-kong and Tawon-kong and those grown in autumn included Taekwang-kong, Pungsannamul-kong, and Cheongja3, respectively. Sowing dates were May 15 and 30, June 15 and 30, and July 15 of each year. Daidzein content was increased in all the test cultivars grown from later sowing, and the contents of genistein and total isoflavone were increased in all the test cultivars except for Cheongja3. On the other hand, glycitein content showed no significant change in any of the test cultivars across the 5 sowing dates except for Tawon-kong. Cyanidin-3-glucoside (C3G) content was significantly increased in Tawon-kong and Cheongja3, and delphinidin-3-glucoside (D3G) and total anthocyanin contents were significantly increased in Tawon-kong. However, pelargonidin-3-glucoside (Pg3G) and petunidin-3-glucoside (Pt3G) contents showed no significant difference in plants sown across the 5 dates. Lutein content in Cheongja3 was between 2.7 and $3.0{\mu}g/g$ based on sowing date and did not vary significantly, while chlorophyll content increased with later sowing and was significantly higher in the cultivars sown on June 30 and July 15. Crude fat content was higher in Taekwang-kong and Cheongja3 when the cultivars were sown earlier; crude fat did not vary in the other test cultivars based on sowing date. Palmitic acid composition was not affected by sowing date in most of the test cultivars. Stearic acid was increased in Saeol-kong, Tawon-kong, and Cheongja3 with later sowing. Oleic acid and linoleic acid were significantly higher in Saeol-kong at an earlier sowing date. The composition of linolenic acid showed significantly increased dates in most of the test cultivars with later sowing. There were no significant differences in carbohydrate and crude protein content across 5 different sowing dates in most of the test cultivars. However, crude protein content was higher in Saeol-kong when sowing occurred earlier, and was higher in Tawon-kong at later sowing dates.