• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.4
• /
• pp.416-421
• /
• 1984

Six soybean cultivars were used to study their seed development and germinability after flowering, in 1977 and 1978. The earlier varieties showed the faster seed development, but indeterminate types resulted in slower development. The earliest germinability was found in 15 to 25 days after flowering when dried with the pod shell. The germination of the seeds dried without pod shell, however, was inhibited significantly in early seed filling stages. Regular germinability of the Hill cultivar in a cold test was 40-45 days after flowering, or 10 to 15 days earlier than the physiological maturity.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.32 no.4
• /
• pp.447-454
• /
• 1987

Five soybean varieties of two early maturing; Karikei 73 and SS79168, and three late maturing; Tohoku 76, Baegunkong and Jangbaegkong, were used and evaluated in the study, Of the varieties examined, Karikei 73 was characterized by the delayed leaf senescence, To investigate the periodical trends of sugars in plant organs and their roles to the nitrogen fixing activity of root nodules, the concentrations of reducing and non-reducing sugar in root and nodules during the grain filling period were measured. The concentration of non-reducing sugar in roots was not changed up to the stage of R6 for all of the varieties but it decreased rapidly thereafter for the varieties except Karikei 73. No such rapid decrease in the concentration of non-reducing sugar in the roots was observed for Karikei 73 having the characteristics of delayed leaf senescence. The concentration of reducing sugar in the root nodules was not greatly changed for all of the varieties up to the stage of R6 regardless of the earliness of varieties but increased temporarily at R6.5 when there was a rapid decrease in ARA. The phenomenon explained the fact that nitrogen fixing activities were controlled not only by supplying sugars as the source of energy for nitrogen fixation, but also by the need for fixed nitrogen of the plant. The concentration of non-reducing sugar in root nodules also increased up to the stage of R6-R6.5 but decreased at R7, which could apply the same explanation as in the concentration of reducing sugar of the root nodules.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.1
• /
• pp.50-56
• /
• 2001

Thirty-three bacterial and fungal strains were isolated from the rotten soybeans and soybean sprouts to isolate pathogenic microorganisms which cause soybean sprouts rot during soybean sprouts cultivation. In pathogenicity tests of the isolates on soybean sprouts, two isolates(K-17 and K-28) caused soybean sprouts rot and were identified as Erwinia carotovora and Fusarium sp., respectively. To isolate antagonists aganist K-17 and K-28 pathogens, bacteria were isolated from various soybean-cultivated soils and screened by the inhibition zone method. A bacterial isolate(J-232) which inhibited growth of both pathogens was identified as Pseudomonas fluorescens and further examined. The culture filtrate of P. fluorescens J-232 (dilution rate of 500 times) inhibited the growth of Erwinia carotovora K-17 and Fusarium sp. K-28 both on potato dextrose agar medium and on soybean sprouts cultivated in vessel. The development of soybean sprouts rots was observed during cultivation by inoculation of soybean seeds with culture filtrate of both pathogens. The combined inoculation of soybean seeds with culture filtrate of antagonistic bacterium and that of pathogens prevented soybean sprouts rot, and the growth of soybean sprouts was similar to that of control. The soybean sprouts inoculated with antagonists culture filtrate alone did not develop soybean sprouts rot, and the growth of the seedlings was shown to be slightly promoted as compared with that of control.

• Korean Journal of Food Science and Technology
• /
• v.17 no.6
• /
• pp.442-446
• /
• 1985

The changes of nitrogen utilization ratio (NUR), Protein solution ratio (PSR) and free sugar contents during the amino acid soysauce manufacturing process by a low hydrochloric acid, temperature were investigated. On hydrolysis by 6%-HCI (3 liquor rate of defatted soybean weight, 3LR) at $85^{\circ}C$, NUR and PSR were 74.51%, 56.49% at 65 hours. At the same time free sugars were detected glucose, galactose, arabinose, fructose, xylose. on hydrolysis at $95^{\circ}C$, NUR and PSR were 77.72%, 64.04% at 50 hours, and 5 free sugars of the above statement were detected at 5 hours. Remarkable decreases in the levels of free sugars, only glucose were observed after 80 hours of the hydrolysis. On hydrolysis by 12%-HCI(3LR) at $95^{\circ}C$, NUR and IRA were 88.41%, 69.47% at 50 hours, free sugar were nearly disappeared after 20-35hours. On hydrolysis, galactose's disappearence rate was faster than glucose's.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.4
• /
• pp.340-347
• /
• 2006

Soyasaponins $A_1$, DDMP-conjugated group B soyasaponins ${\alpha}g\;and\;{\beta}g$, non-DDMP counterpart soyasaponin I, II+III, and DDMP moiety were quantified in the large-, midium-, and small-seed soybean varieties. Protein contents were ranged from 38.1% to 41.8%, and oil contents were ranged from 15.5% to 18.9%, respectively. Oil contents in the large-seed varieties were significantly higher than those of medium- and small-seed varieties. Among detected soyasaponin peaks, ${\beta}g$ was a major soyasaponin in DDMP-conjugated group B soyasaponins followed by soyasaponin I, DDMP moiety and $A_1$. Soyasaponin concentration among different seed size soybean varieties. The soyasaponin concentration of mediumseed ($4014.5{\mu}g/g$) was slightly higher than those of largeseed ($3755.0{\mu}g/g$) and small-seed varieties ($3620.3{\mu}g/g$), however, the differences was statistically not significant. The composition rates of soyasaponins in the large-size seeds were 9.4% of soyasaponin $A_1$, 26.5% of DDMP-conjugated soyasaponins, 49.9% of non-DDMP counterpart soyasaponins, and 14.2% of DDMP moiety, respectively. Similar results were observed in the composition ratios of middle- and small-size seeds. Oil content and C:N ratio showed the significant positive correlations with total soyasaponin concentration, while the 100-seed weight, fiber, and ash contents showed the negative correlations with total soyasaponin but statistically not significant. It was noted that protein contents didn't have any relationship with group A, group B, DDMP moiety, and total soyasaponin. This fact suggested that protein contents are not affects the variation of soyasaponin concentration.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.5
• /
• pp.592-599
• /
• 1996

The variations of asparagine and aspartic acid contents among the soybean varieties and in the different parts of soybean sprout after the different durations of storage were investigated. Asparagine and aspartic acid are known to have the detoxifying effects on acetaldehyde, which is highly toxic metabolites in the process of alcohol metabolism in the human body. The contents of asparagine and aspartic acid of beansprout showed continuosuly increasing trends along with the days to cultivation with a great varietal difference, especially in the roots. The duration of seed storage did not affect contents of asparagine content; the longer storage decreased aspartic acid content remarkably.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.33 no.4
• /
• pp.420-428
• /
• 1988

Root is supposed to be important role in growth and yield formation of soybeans and also there is expected to exist varietal differences between soybean root morphology and system. 30 soybean varieties including 10 Korean recommended, 10 Introduced and 10 Korean native varieties were grown at field and pot under standard culture condition. Top and root characteristics were investigated at V4, R1 and R5 stage and T/R relations, correlations with yield were calculated. Top characteristics showed significant difference between 3 variety groups of Korean recommended, Introduced and Korean native variety. Stem length at R1 stage and stem length, stem diameter, number of nodes, number of branches, number of pods and grain yield at R5 stage were significantly different top characteristics. Root characteristics showed significant difference between 3 variety groups were number of thick primary root at V4 stage, primary root angle and root cutting strength at R1 stage, thick root diameter and root dry weight at R5 stage. The correlations between top and root characteristics and soybean yield was greatly different by soybean variety groups, and the top characteristics was more highly correlated then root characteristics. All the top and root characteristics of Korean recommended variety showed no correlations with yield. However, leaf area, stem length, top dry weight in Introduced variety and leaf area, top dry weight, number of nodes, number of thick primary root in Korean native variety were highly correlated with soybean yield.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.1
• /
• pp.102-109
• /
• 2008

This study was performed to obtain fundamental information on growth adaptability and isoflavone contents of soybean cultivars in highland area of Korea. For this study, we cultivated nineteen cultivars and investigated yield and isoflavone contents. In Jinbu-myeon located at altitude of 600 m, most of cultivars showed more than 2.5 t/ha seed yield except three cultivars, and the range of isoflavone contents among nineteen cultivars was 715 to $2,545\;{\mu}g/g$. Cultivars with both high seed yield and isoflavone contents were Manrikong, Sinpaldalkong2, Cheongjakong, and Cheongjakong2 in this area. In Daegwallyeong-myeon located at altitude of 800 m, the range of seed yield and isoflavone contents was 1.4 to 2.4 t/ha and 437 to $2,370\;{\mu}g/g$, respectively. Cultivars with both high seed yield and isoflavone contents were Ilpumgeomjeongkong and Dooyookong in this area. Cultivars selected on the basis of seed yield and isoflavone contents in 2004 and 2005 showed also similar results for yield and isoflavone contents at farmer's field in highland area in 2006. In conclusion, it could be expected to produce soybeans having both higher yield and better quality if the selected soybean cultivars are cultivated in highland area.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.1
• /
• pp.64-69
• /
• 2008

The objective of experiment was to investigate the effects of planting density on growth and yield of vegetable soybean, and to clarify the optimum planting density of vegetable soybean in the middle west region of Korea. The field experiment with 4 levels of planting density was carried out at Yesan area in $2005{\sim}2006$. The days from seeding to flowering and the days from seeding to harvesting and lodging were not significantly different among planting distance. The stem length was increased as planting distance was shortened but the number of node, branch, pod per branch, pod per individual, weight of stem and pod, one hundred pod weight and rate of 2+3 seed per pod were decreased as planting density was increased. The size of vegetable soybeans was not significantly different among planting distance, but the harvest index of vegetable soybean was decreased as planting distance was shortened. Yield of vegetable soybean was increased as planting distance was decreased. However, the approriate densities for stem and pod weight per a plant, number of pod per a branch and the vegetable soybean yield of 2+3 seed per pod were different from that density. The optimal planting distance of varieties was $60{\sim}25\;cm$ in Sunheukkong and Ilpumgeomjeongkong and was $60{\sim}35\;cm$ in Galmikong.

• Korean Journal of Food Science and Technology
• /
• v.27 no.1
• /
• pp.19-24
• /
• 1995

The effect of several inhibitors such as ascorbic acid on the lipoxygenase in soybeans known to catalyze reaction resulting in racid off-flavors was examined in the soybean homogenates by the oxygen electrode method. Among 8 compounds added at homogenizing process, 10 mM ascorbic acid inhibited lipoxygenase-1 and lipoxygenase-2/3 activities to 41.7 and 49.8%, respectively. Inactivation of lipoxygenase-2/3 was highly accelerated by homogenization for 15 min at room temperature, so the activity was inhibited 70.8% comparing with the homogenization of 3 min. When soybean homogenates with 10 mM ascorbic acid was stored at $25^{\circ}C$ for 72 hrs, lipoxygenase-2/3 activities lowered to 52.8% whereas L-1 activities lowered to 15.8%. Since it is reported that lipoxygenase-2 is responsible for the off-flavor of soybean products, the inhibitory effect of ascorbic acid among several inhibitors investigated might be useful in soybean processing.