• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.263-268
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• 2008

Bacterial leaf pustule (BLP) caused by Xanthomonas axonopodis pv. glycines is a serious disease to make pustule and chlorotic haloes in soybean [Glycine max (L). Merr.]. While inheritance mode and map positions of the BLP resistance gene, rxp are known, no sequence information of the gene was reported. In this study, we made five near isogenic lines (NILs) from separate backcrosses (BCs) of BLP-susceptible Hwangkeumkong $\times$ BLP-resistant SS2-2 (HS) and BLP-susceptible Taekwangkong$\times$ SS2-2 (TS) through foreground and background selection based on the four-stage selection strategy. First, 15 BC individuals were selected through foreground selection using the simple sequence repeat (SSR) markers Satt486 and Satt372 flanking the rxp gene. Among them, 11 BC plants showed the BLP-resistant response. The HS and TS lines chosen in foreground selection were again screened by background selection using 118 and 90 SSR markers across all chromosomes, respectively. Eventually, five individuals showing greater than 90% recurrent parent genome content were selected in both HS and TS lines. These NILs will be a unique biological material to characterize the rxp gene.

• 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.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.43-53
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• 2011

The possibility of making Cheongukjang by the use of soy-powder and pill type re-made from soy-powder was investigated. Some of experimental results obtained are summarized as follows; 1. Regardless of three different types for the source material of Cheonggukjang, soybean seed, soy-power, and pill, the dry weight of fermented Cheonggukjang showed continuously decreasing trends along with the time of fermentation applied. 2. In all type of source materials, the length of viscous substance during fermentation was increased along with the time of fermentation, and the rate of elongation was much reduced after 48hr of fermentation. Out of four soybean varieties tested, Taekwangkong produced longest viscous substance fermented in the type of soybean seed. No viscous substance was formed when the depth of soy-powder in the fermentation box was shallow, one centimeter. 3. Not much difference was observed in the number of microbes, Bacillus licheniformis B1, in all soybean varieties. The number was proportionally increased in the type of powder but it increased rapidly from 12 hour to 24 hour with low rate of increase thereafter in the pill type. 4. Along with the time of fermentation in all types, the color of Cheonggukjang changed from yellow to dull. At the same time, the tone of color and chroma changed into reddish and yellow, respectively. 5. Along with the time of fermentation in all types, pH of Cheonggukjang changed in alkali. 6. Along with the time of fermentation, the content of isoflavone in Cheonggukjang increased by 48hr but decreased thereafter. 7. In general, the quality of Cheonggukjang fermented in types of soy-powder and pill re-made from soy-powder was lower than that of soybean seed. More study is seemed to be needed to produce high quality Cheonggukjang by the use of soy-power.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.143-152
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• 2008

This study was conducted to obtain basic information on mainstem, branch and leaf characteristics related to canopy for development of high yielding cultivar using 70 Korean soybean cultivars developed from 1913 to 2000. Variations of canopy width, branch length, and canopy width/length ratio were higher compared to other characteristics among 12 mainstem and branch characters. Variations of petiole angle, leaflet width/length ratio and compound leaf dry weight were higher than other characteristics among eight leaf characters related to plant canopy. Three classifications of soybean cultivars were used based on usage: I)soy sauce and tofu, II)bean sprout, and III)cooking with rice. Canopy width/length ratio was higher in group III, cooking with rice than group I, soy sauce and tofu, and group II, bean sprout, and there was no difference between the two, group I and group II. The total branch length/main stem height ratio was higher in group II, bean sprout and group III, cooking with rice than group I, soy sauce and tofu. Mainstem and branch characteristics related to plant canopy were classified into four groups by ratio of canopy width/length and total branch length/main stem length, respectively. Soybean cultivars with narrow canopy and high dependence of mainstem were Danweonkong, Keumkangkong, Shelby, and Shinpaldalkong. Soybean cultivars with broad canopy and high dependence of mainstem were Kanglim, Keumkangdaelip, and Jinyulkong, and a cultivar with broad canopy and high dependence of branch were Geomjeongkong 2. Leaflet length/width ratio was lowest in cooking with rice and there was no difference between soy sauce and tofu and bean sprout. Compound leaf area was largest in cooking with rice and smallest in bean sprout. Leaf petiole length was short in bean sprout and there was no difference between soy sauce and tofu and bean sprout. Leaf petiole angle was highest in cooking with rice and lowest in bean sprout. Leaf type was classified into four groups based on leaflet width/length ratio and compound leaf area, respectivly. Buseok and Taekwangkong had an oval leaflet and largest area of compound leaf. Eunhakong and Sohokong had extreme narrow leaflet and smallest area of compound leaf. Leaf petiole type was classified into three and four groups based on leaf petiole length and angle, respectively. A soybean cultivar with the shortest petiole length and smallest petiole angle was Eunhakong and cultivars with short petiole length and large petiole angle were Alchankong, Muhankong, and Pureunkong. A soybean cultivar with long petiole length and small petiole angle was Sinpaldalkong 2. Among a total of 70 Korean soybean cultivars, Eunhakong had an extreme narrow type in leaf, smallest compound leaf area, shortest petiole length, and smallest petiole angle of compound leaf.