• Research in Plant Disease
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• v.17 no.3
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• pp.317-325
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• 2011

Bacterial pustule of soybean (Glycine max) caused by Xanthomonas axonopodis pv. glycines is one of the most prevalent bacterial diseases of soybean in Korea, where it causes considerable yield loss. This study was carried out to develop yield prediction model for bacterial pustule by analyzing correlation between the percentage of diseased leaf area and yield. The severe disease incidence of soybean bacterial pustule caused yield losses by 19.8% in 2006 and 16.8% in 2007, respectively. Severity of bacterial pustule greatly affected on 100 seed weight and yield, but did not on stem length, number of branches per plant, number of pods per plant, number of seeds per plant. On the other hand, correlation coefficients between diseased leaf area and yield were $-0.93^*$('06) and $-0.77^*$('07), respectively. The regression equation obtained by analyzing correlation between the percentage of diseased leaf area and yield loss in 2006 and in 2007 was y = -3.2914x + 348.19($R^2$ = 0.8603) and y = -2.9671x + 302.08($R^2$ = 0.9411), respectively. These results will be helpful in estimating losses on a field-scale and thereby predicting the production of soybean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.232-237
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• 2003

Benzyladenopuyine (BA) commonly used for soybean sprout production is of high price. The study was carried out to determine the effect of BA treatment time during seed imbibition on growth and development of soybean sprouts and to analyse its treatment cost. The soybean seeds of 4 cultivars were soaked in 4 ppm BA solution during the first 5.5 hour imbibition (EFHI), the second 5.5 hour imbibition (SFHI) immediately after 0.5 hour aeration, or whole 11.0 hour imbibition (WFHI) intervened by aeration. On the 6th day after culture, the soybean sprouts were classified into 4 categories on the base of hypocotyl length; ＞ 7cm, 4 to 7cm, ＜ 4 cm and not germinated, and their morphological characters, fresh and dry weights were measured. Water absorption of the seeds was sharply reduced after it was almost done for the first 5.5 hours. The percentage of sprouts with hypocotyls of longer than 4cm was higher in FFHI treatment than in the other two ones. Regardless of BA imbibition time and periods, the lateral roots were not observed. WFHI treatment showed shorter hypocotyl and root lengths but thicker hypocotyl and hook diameters than FFHI and SFHI treatments. All component fresh and dry weights except cotyledon fresh weight were nearly same. Treatment cost of BA was the lowest in SFHI treatment. It is concluded that BA treatment during SFHI is the best time because its treatment time did not affect sprout growth but its treatment cost.

• Applied Biological Chemistry
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• v.37 no.1
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• pp.19-24
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• 1994

Eight varieties of soybeans grown in Korea were investigated to compare chemical composition, protein dispersibility index (PDI) and some properties of soybean sprouts and tofu. The range of protein contents was $37.80{\sim}40.43%$ where the Kyungdong 3 was the highest and Suwon 157 was the lowest, while the Bokwang was the lowest in lipid contents. The range of PDI was $71.6{\sim}95.3%$ where the Kyungdong 3 was the highest and Suwon 162 was the lowest. The Kyungdong 3, Suwon 160 and Suwon 162 were significantly fast in growth rate of soybean sprout roots and the 100% of germination. The Kyungdong 3 was the highest in tofu yield and Suwon 146 was the highest in hardness. The organoleptic properties of tofu showed that $L{\times}2.3$ and Suwon 162 was relatively high in cooked beany odor, while the Suwon 146 were the highest in elasticity and hardness. Even though Kyungdong 3 was found as the best for tofu and soybean sprouts processing, the black color of seed coat affected negatively on tofu color.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.1 no.1
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• pp.3-25
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• 1963

Experiments were carried out to classify the ecotypes and maturity groups of soybean varieties, and to make clear the relationships among these ecotypes, maturity groups and some characteristics in the growing and ripening process of soybean varieties in Korea. Soybean varieties used as the material were 138, 57 varieties collected from Japan, America and Canada and 81 local varieties of Korea. These varieties were grown in the Experimental Farms, College of Agriculture, Seoul National University, Suwon, Korea and Chinju Agricultural College, Kyungsang Namdo, Korea. Seed sowing was conducted at 8 times from April15 to July 29, at 15 day-intervals, in 1962. The classification methods of ecotypes and maturity groups applied in this study, and the results obtained are summarized as follows; 1. Ecotypes were classified from the standpoint of the periods from emergence to flowering, the shortened ratio of days from sowing to flowering by delayed sowing, and the periods from flowering to maturity(as shown in Table A). 2. All varieties wer classified into 10 ecotypes of Ia$_1$, Ib$_1$, IIa$_2$, IIb$_1$, IIb$_2$, IIIb$_1$IIIb$_2$, IIIc$_1$and IIIc$_2$ symbols. Korean local varieties, however, belong to 6 ecotypes of IIb$_1$, IIb$_2$, IIIb$_1$, IIIc$_2$, IIIc$_1$ and IIIc$_2$, respectively(table 1). 3. Durations from sowing to maturity were from 120 to 190 days in April sowing plots of all varieties. From the standpoint of the durations, maturity groups were classified into 9 groups from group I, extreme early, to group IX, extreme late, but our local varieties belong to 5 maturity groups of III, IV, V, VI and VII symbols, respectively(Table 2). 4. Kinds of ecotypes and maturity groups, and the number of soybean varieties belonging to those are as shown in Table B. 5. In this study, it was observed that there were some close relations between these ecotypes and maturity groups (Table 3,4), and among the ecotypes, maturity groups and some other characteristics in the growing and ripening process of the soybean varieties(Table 5). 6. Furthermore, it was also observed that the kinds of ecotypes and maturity groups of recommended varieties in the southern Korean provinces are more numerous than those of the northern provinces in Korea.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.239-239
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• 2017

The enhancement of leaf photosynthetic capacity can have the potential to improve the seed yield of soybean. Key targets for the increase of leaf photosynthetic capacity remains unclear in soybean. Peking, Chinese local variety, has been the useful material for soybean breeding since it shows various resistances against biotic and abiotic stress. Sakoda et al., 2017 reported that Peking had the higher capacity of leaf photosynthesis than Enrei, Japanese elite cultivar. They identified the genetic factors related to high photosynthetic capacity of Peking. The objective of this study is to elucidate the physiological basis underlying high photosynthetic capacity of Peking. Peking and Enrei were cultivated at the experimental field of the Graduate School of Agriculture, Kyoto University, Kyoto, Japan. The sowing date was July 4, 2016. Gas exchange parameters were evaluated at the uppermost fully expanded leaves on 43, 49, and 59 days after planting (DAP) with a portable gas exchange system, LI-6400. The leaf hydraulic conductance, $K_{leaf}$, was determined based on the water potential and transpiration rate of the uppermost fully expanded leaves on 60 DAP. The morphological traits related to leaf photosynthesis were analyzed at the same leaves with the gas exchange measurements. The light-saturated $CO_2$ assimilation rate ($A_{sat}$) of Peking was significantly higher than that of Enrei at 43 and 59 DAP while the stomatal conductance ($g_s$) of Peking was significantly higher at all the measurements (p < 0.05). It suggested that high $A_{sat}$ was mainly attributed to high $g_s$ in Peking. $g_s$ is reported to be affected by the morphological traits and water status inside the leaf, represented by $K_{leaf}$, in crop plants. The tendency of the variation of the stomatal density between two cultivars was not consistent throughout the measurements. On the other hand, $K_{leaf}$ of Peking was 59.0% higher than that of Enrei on 60 DAP. These results imply that high $g_s$ might be attributed to high $K_{leaf}$ in Peking. Further research is needed to reveal the mechanism to archive high $g_s$ on the basis of water physiology in Peking. The knowledge combining the genetic and physiological basis underlying high photosynthetic capacity of Peking can be useful to improve the biomass productivity of soybean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.246-268
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• 2019

Soybean [Glycine max (L.) Merr.] is a species of legume native to East Asia. The interactions between climatic conditions and genetic characteristics are known to affect the agricultural performance of soybean. Therefore, the present investigation was conducted to identify the main elements affecting the agricultural performances of 11 soybean varieties/lines from China [Harbin ($45^{\circ}12^{\prime}N$), Yanji ($42^{\circ}53^{\prime}N$), Dalian ($39^{\circ}30^{\prime}N$), Qingdao ($36^{\circ}26^{\prime}N$)] and the Republic of Korea [Suwon ($37^{\circ}16^{\prime}N$), and Jeonju ($35^{\circ}49^{\prime}N$)]. The days to flowering (DTF) of soybeans with the e1-nf and e1-as alleles and the E1e2e3e4 genotype, except in 'Keumgangkong', 'Tawonkong', and 'Duyoukong', were relatively short compared to those of soybeans with other alleles. Although DTF of the soybeans was highly correlated with all climatic conditions [negative: precipitation, average temperature (AVT), accumulated temperature; positive: day-length (DL)], days to maturity and 100-seed weight of the soybeans showed no significant correlation with any climatic conditions. The soybeans with a dominant Dt1 allele, except 'Tawonkong', had the longest stem length (STL). Moreover, STL of the soybeans grown in the test fields showed a positive correlation with only DL; however, the results of our chamber test that was conducted to complement the field tests showed that STL of soybean was positively affected by AVT and DL. Although soybean yield (YLD) showed positive correlations with latitude and DL (except L62-667, OT89-5, and OT89-6), the response of YLD to the climatic conditions was cultivar-specific. Our results show that DTF and STL of soybeans grown in six different latitudes are highly affected by DL, and AVT and genetic characteristic also affect DTF and STL.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.528-533
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• 1992

Soybean seeds contain lipoxygenase, which is responsible for the objectionable beany flavors in soybean seeds. The isozymes of lipoxygenase (1$\times$1, 1$\times$2, 1$\times$3) were discovered in United States of America, Japan, and Korea, and the mode of inheritance of the mutant genes was determined. This investigation was conducted to screen lipoxygenase-1, 2, and 3 lacking soybean lines from the Korean soybean land race population. Two lipoxygenase-1lacking lines, KAS 610-8 and KAS 621-8 were found in this investigation. In general, lipoxygenase acking varieties were small in seed size and low in oil content. A severe pod borer damage was observed in the two selected lipoxygenase-1 lacking lines. Lipoxygenase lacking line was not found in Korean wild soybean population used in this study and the lipoxygenase lacking lines were found only in Kyung-Nam province and the results imply that lipoxygenase lacking mutants were induced recently in cultivars.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1339-1347
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• 2003

An experiment was conducted to investigate the effects of microbial phytase ($Natuphos^{(R)}$) supplementation in combination with carbohydrases (composed of enzymes targeted to soybean meal (SBM) dietary components such as $\alpha$-galactosides and galactomannans; $Endo-Power^{(R)}$) to corn-soybean meal based diet (CSD) and complex diet (CD) with a partial replacement of SBM with rape seed meal (RSM) and cotton seed meal (CSM) on growth performance and nutrient digestibility of growing pigs. A total of 168 growing pigs averaging $13.18{\pm}1.77kg$ of initial body weight was arranged as a $2{\times}2$ factorial design with main effects of diet types (corn-SBM based diet (CSD) and complex diets (CD; 5% of SBM was replaced with 2.5% of RSM and 2.5% of CSM in diet for phase I (0 to 3 weeks) and 6% of SBM was replaced with 3% of RSM and 3% of CSM in diet for phase II (4 to 7 weeks))) and enzyme supplementation (none and 0.1% of phytase (500 FTU/kg diet) and 0.1% of carbohydrases). The diet with enzyme application were formulated to have a 0.18% unit lower aP than diets without enzyme application. Each treatment had three replicates with 14 pigs per replicate. To determine supplementation effect of phytase and carbohydrases on ileal amino acid digestibility of SBM, RSM and CSM, a total of 18 T-cannulated pigs (initial body weight; $13.52{\pm}1.24kg$) were assigned to six dietary treatments in the present study. Dietary treatments in metabolic trial included 1) SBM diet, 2) SBM diet+with enzymes (phytase (500 FTU/kg) and carbohydrases at 0.1%, respectively), 3) CSM diet, 4) CSM diet+enzymes, 5) RSM diet and 6) RSM diet+enzymes. During whole experimental period (0 to 7 wks), there was no difference in growth performance between diets (CSD and CD). However, dietary phytase and carbohydrases supplementation significantly improved gain/feed ratio (G:F) of growing pigs. During the phase II (4-7 weeks), dietary phytase and carbohydrases supplementation significantly improved all fecal nutrient digestibilities (Dry matter (DM), gross energy (GE), crude protein (CP), crude fat (CF), calcium (Ca) and phosphorus (P)). Dietary phytase and carbohydrases supplementation improved significantly overall ileal amino acid digestibilities of SBM, RSM and CSM based diets (p<0.05). The simultaneous inclusion of phytase and carbohydrases in both of CSD and CD reduced feed cost per kg body weight gain (FCG). Also, results suggest that 2.5 to 3% of RSM and CSM, respectively, might be used as a protein source in growing pig diets without having an adverse effect on the growth performance and nutrient digestibility and simultaneous phytase and carbohydrases addition improves nutritional value of SBM, RSM and CSM by improving ileal amino acid digestibilities.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.640-646
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• 1997

To determine variations in leaflet length (LL), leaflet width (LW), leaflet size (LS), and leaflet shape index (LSI), and their association with eight agronomic traits, characterization data of 884 soybean accessions which were grown in the autumn of 1992 in Taiwan were analyzed. LL ranged from 4.3 to 14.7 cm, and LW ranged from 2.8 to 9.7 cm. Also, LS (LL $\times$ LW) ranged from 12.1 to 124.6 $\textrm{cm}^2$. The absolute variation of LL, LW, and LS was not large because of limitation in vegetative growth by short day length. None was classified as a large leaflet based on the International Board for Plant Genetic Resources (IBPGR) descriptors. LSI (LL /LW) ranged from 1.21 to 3.06, and three accessions were classified as narrow leaflet. There were differences in ranges and means of LL, LW, LS, and LSI between and within temperate and tropical accessions. LL, LW, LS, and LSI had highly significant positive correlations with seven agronomic traits and highly significant negative correlation with 100-seed weight except LW for all accessions. There was variation in the closeness of association among leaflet traits, and between and within temperate and tropical accessions. Generally, LL, LW, and LS were more closely associated with days to flowering, plant height at $R_1$ and $R_8$, number of pods per plant; LSI was more closely associated with 100-seed weight than other traits.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.189-195
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• 1993

This study was conducted to obtain the .basic informations for developing soybean varieties and mechanizing cultivation at the Crop Experiment Station, Rural Development Administration, Suwon, Korea in 1990. Two determinate soybean varieties, Hwangkeurnkong and Jangyeobkong, and two indeterminate soybean varieties, Clark and Williams were planted at three planting densities (33,22,16 plants / $m^2$). Number of branches and number of nodes on branches per unit area ($m^2$) were greater in determinate varieties than in indeterminate ones, and number of nodes on mainstem were greater in indeterminate varieties than in determinate ones. The higher planting density increased those characters. Seed weight per unit area ($m^2$) was higher in determinate varieties than in indeterminate ones, and it was great at the higher planting density. Indeterminate varieties showed greater mainstem dependence rate for yield components than determinate ones did. Harvest index was higher in indeterminate varieties than in determinate ones. The lower planting density increased harvest index. Stem dry weight per unit area($m^2$) was greater in determinate varieties than in indeterminate ones, and it was greater at the higher planting density. Variations among plants were great in the order of branch-related yield characters > total plant-re-lated yield characters > mainstem-related yield characters > morphological characters of mainstem and 100 seed weight. Difference between determinate and indeterminate varieties was significant in branch-related characters. Indeterminate varieties showed greater variations than determinate ones did in branch-related yield characters at different planting densities.