• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.53-60
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• 2022

Recently, Black soybean (Glycine max L. Merr.) is being cultivated in paddy fields instead of rice. However, research related to the effective sowing date is insufficient in paddy fields. This study aimed to identify the sowing date for stable cultivation of black soybean by investigating its yield and seed characteristics in a paddy field. In the study, cultivation experiment with five different sowing dates (May 25, June 10, June 25, July 10, July 25) were conducted in 2019 and 2020. Days from sowing to flowering can be shortened by delaying the sowing date. In the present study, the yield of black soybean in paddy fields was the highest with June 10 as the sowing date and was calculated as 224 kg·10a^-1 and 200 kg·10a^-1 in 2019 and 2020, respectively. However, the highest values of seed coat cracking was 51.1±5.1% and that of total anthocyanin contents was the 3.99±0.72 mg/g, both of which were observed in 2020 for the experiment with May 25 as the sowing date. Regression analysis showed a positive correlation (R²=0.9312) between soil water contents and seed coat cracking rate during the flowering period. Hence, the soil water contents during the flowering period would have a negative effect on the seed coat development.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.165-176
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• 2010

Soybean seeds contain many biologically active secondary metabolites, such as proteins, saponins, isoflavones, phytic acids, trypsin inhibitors and phytosterols. Among them, saponins in soybeans have attracted considerable interest because of their health benefits. Soyasaponin A and B are the most abundant types of saponins found in soybeans along with soyasapogenol (aglycone), which is a precursor of soyasaponin. The main purpose of this experiment was to determine the concentration of soyasapogenol in soybean seeds and sprouts as a function of seed size, usage, seed coat color and seed cotyledon color. The 79 Korean soybean varieties were cultivated at Yesan of Chungnam in 2006 for the analysis of soyasapogenol using HPLC with Evaporative Light Scattering Detection (ELSD). The total average concentration of soyasapogenol was $1313.52{\mu}g\;g^{-1}$ in soybean seeds and $1377.22{\mu}g\;g^{-1}$ in soybean sprouts. Soybean sprouts were about 5% higher than soybean seeds in average total soyasapogenol concentration. In the process of sprouting, the average soyasapogenol A content decreased by approximately 1.6%, but soyasapogenol B and total soyasapogenol increased by 8.31% and 4.88%, based on the content of soybean seeds. When classified according to the size of seeds, the total soyasapogenol concentration of soybean seeds were not significantly different (p<0.05) On average, small soybean seeds were increased by as much as $103.14{\mu}g\;g^{-1}$ in sprouting process. As a function of the use of the seeds, The total soyasapogenol in soybean seeds were significantly different (p<0.05). While, the soybean sprouts were not significant different (p<0.05). Altogether, sprout soybean seeds show the greatest change in content during the germination process. When seeds with different coat colors were compared, the total soyasapogenol concentration of soybean with yellow seed coats ($1357.30\mu g\;g^{1}$) was slightly higher than that of soybean with black ($1260.30{\mu}g\;g^{-1}$) or brown ($1263.62{\mu}g\;g^{-1}$) seed coats. For the color of the cotyledon, the total soyasapogenol concentration was significantly increased in green cotyledon during the germination and seedling process. The results of this study suggest the functional characteristics of soybeans through quantitative analysis of soyasapogenol. In addition, the concentration of soyasapogenol exhibited a change during the germination process, which was evaluated by the nutritional value of the soybean sprouts.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.1-7
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• 2008

Soybeans with brown, black, and yellow seed coats were compared to total phenolic contents and antioxidant activities including 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals. Also, 3 seed coats were examined for inhibitory activities on tyrosinase and lipoxygenase-1 on the basis of spectrophotometric and polarographic methods. Among seed coat extracts, 80% methanol extract of brown soybean seed coat showed the highest total phenolic contents ($68.9{\pm}3.29\;mg$ GAE/g) as well as exhibited potent scavenging effects on the DPPH ($IC_{50}=4.3\;{\mu}g/mL$) and ABTS ($IC_{50}=3.7\;{\mu}g/mL$) radicals. In a polarographic experiment, this extract was potentially inhibited the oxidation of L-tyrosine and L-3,4-dihydroxy-phenylalanin (L-DOPA) catalyzed by mushroom tyrosinase with $IC_{50}$ values of 12.4 and $63.7\;{\mu}g/mL$, respectively. It was also detected inhibition of the tyrosinase catalyzed oxidation of L-DOPA with an $IC_{50}$ value of 120.3 mg/mL in UV spectrophotometric experiment. In addition, this extract inhibited the linoleic acid peroxidation catalyzed by lipoxygenase-1 with an $IC_{50}$ value of $4.0\;{\mu}g/mL$. These results suggest that brown soybean may possess more beneficial effect on human health than black and yellow soybeans.

• Journal of Life Science
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• v.28 no.11
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• pp.1285-1289
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• 2018

Soybean [Glycine max (L.) Merr.] seed is an important dietary source of protein, oil, carbohydrates, isoflavones, and other nutrients for humans and animals. But, antinutritional factors in the raw mature soybean are exist. Kunitz trypsin inhibitor (KTI) protein and stachyose are main antinutritional factors in soybean seed. The genetic removal of the antinutritional factors will improve the nutritional value of soybean seed. The objective of this research was to breed a new yellow soybean strains (rs2rs2titi genotype) with the traits of lacking of KTI protein and low content of stachyose. Breeding population was developed from the cross of "Jinyangkong" and 15G1 parents. Presence or absence of KTI protein was detected based on Western Blot technique. Content of stachyose in mature seed was detected by HPLC. Total four new strains (603-1, 603-2, 625, and 694) with KTI protein free and low content of stachyose were selected. Four strains (603-1, 603-2, 625, and 694) have yellow seed coat and hilum. Plant height of 603-1 strain was 65 cm and 100-seed weight was 29.2 g. Plant height of 603-2 strain was 66 cm and 100-seed weight was 26.2 g. Plant height of 625 strain was 64 cm and 100-seed weight was 27.1 g. Content of stachyose for four new strains was 3.0~3.50 g/kg. Four strains selected in this research will be used to improve new yellow soybean cultivar with KTI protein free, and low content of stachyose.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.299-306
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• 2005

Soybean seed injury was analyzed in the experiments that soybean pods were allowed to be sucked by adults of the bean bug, R. clavatus, and were picked with a specimen pin. While attack by the bean bug at podding stage of soybean caused the increase of empty pods and completely-undeveloped seeds, attack at full seed stage caused the increase of seeds wi distinct injury mark on seed-coat. The ratio of deformed seed was lower than those of injury-marked seed and undeveloped seed when attacked during all stages. In at full bloom stage hardly produced injury-marked seeds and deformed seeds. When the injured seeds were dyed with acid-fuchsine solution, stylet sheaths of R. clavatus formed on seed-coat were observed in 83% of undeveloped seeds formed under attack during podding stage and in 91% of injury-marked seeds formed during full seed stage. In pods injured with a specimen pin at full seed and full maturity stages, no healthy seeds could be obtained from the pods. And the more picked at full seed stage, the more deformed seeds were produced and the higher weight reduction of injury-marked seed occurred. However, pin-injury at full maturity stage didn't give rise to weight reduction of seeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.59-65
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• 2006

The impermeable seed coat is valuable trait in soybean because impermeable seed retain viability for longer period than permeable seed under adverse conditions such as delayed harvest or prolonged storage. Soybean seeds of various size showing different seed hardness were examined for their water absorption and seed viability under adverse storage conditions. Of one hundred thirty nine genotypes, eight types of seeds having different seed hardness and seed size were used as material. Soybean genotypes showing high hard seed rate, GSI13125 (89%), GSI10715 (54%), and GSI10284 (42%), were slow in water absorption and low in the electroconductivity of seed leachate in distilled water. Germination of GSI10284 and GSI13125 that have higher hard seed rate was less affected by CSVT and artificial aging treatment indicating higher seed storability. The higher storing ability of both collections was confirmed by electroconductivity test for leachate. GSI10122 showed low seedling emergence when the seeds were artificially aged. This genotype was considered as to having a poor storing ability based on difference of electroconductivity before and after artificial aging. Among tests conducted in the experiment, CSVT could be used for determining storage life in legumes. In conclusion, water absorption property of seed was strongly related to the hardness that is directly related to the seed viability and storing ability in soybean seed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.123-126
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• 2002

Lipoxygenase might be associated with seed deterioration by catalyzing the incorporation of molecular oxygen into fatty acids and generating free radicals. This study was performed to determine whether seed lipoxygenase activity would alter soybean seed longevity. In this study, germination percentage of lipoxygenase-lacking cultivar Jinpumkong2 (lx1lx1lx2lx2lx3lx3) was lower than that of Taekwangkong (Lx1Lx1Lx2Lx2Lx3Lx3). Segregation ratio for the three lipoxygenase isozymes of the F2-derived from the cross between Taekwangkong and Jinpumkong2 was fitted to 9 (Lx1Lx2Lx3) : 3 (Lx1Lx2lx3) : 3 (lxllx2Lx3) : 1 (lx1lx2lx3), suggesting the tight linkage between the Lx1 and Lx2 loci. Germination percentages varied widely but not differed among lipoxygenase isozyme types of F$_3$ seeds before and after accelerated aging. Seed coat of Jinpumkong2 was damaged severely following accelerated aging, whereas that of Taekwangkong was not. Thus, seed of lipoxygenase-lacking soybean cultivar, Jinpumkong2 showed greater deterioration compared with that of the normal Taekwangkong. However, the presence or absence of lipoxygenase activity had no effect on soybean germination.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.187-194
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• 2010

The soybean stay green mutant genotype (SSG) derived from the nuclear gene, d1d2, and cytoplasmic gene, cytG, inhibit the breakdown of chloroplast in the leaves, pod walls, seed coats, and embryos during maturity. Soybean seed with black seed coat and green cotyledon (SBG) are preferred than black seed coat with yellow cotyledon (SBY) especially for cooking with rice and as source of traditional food in Korea. The researchers evaluated the seed's chlorophyll content of SSG and introduced SSG to the SBG variety breeding program. The seed chlorophyll content of SSG with d1d2 was $39.93{\sim}60.80\;{\mu}g/g$ and SSG with cytG $38.08{\sim}39.89\;{\mu}g/g$. The Korean SBG variety which was derived from SSG with cytG, contains $16.35{\sim}37.73\;{\mu}g/g$. The composition of seed chlorophyll differs according to the genetic background of SSG genotype. Inheritance study showed that cotyledon color was segregated 15:1 (yellow:green) at $F_2$ seed indicating two recessive genes control green cotyledon as revealed by previous study. Only less than 3% soybean lines showed black seed coat with green cotyledon among crosses SBY and SSG (d1d2). Results showed that SSG with d1d2 can be used as a good source for SBG with high chlorophyll content in the seed cotyledon, but due to the complex genetic behavior, breeding resource of SBG with d1d2 should be prepared to improve the breeding efficiency for development SBG variety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.331-338
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• 1994

The experiment was conducted to determine if seed size and seed coat color of soybean might be effective in water uptake and cotyledon damage after imbibition, and hypocotyl elongation. Eight soybean cultivars were separated into two classes of large and small seed based on seed weight, and each class included two cultivars with yellow and black seed color, respectively. Small seed size group was superior in water uptake by seed for 24 hour in imbibition at $25^{\circ}C$ , but its differences decreased as soaking time increased. Small seed cultivars germinated faster and had better germination rate than large ones. However, cultivars with black seed coat showed more slow water uptake at initial time and faster germination than yellow seed, but in 24 hour after imbibition, cultivars with black seed coat had higher water uptake rate than yellow seeds. Small seed cultivar group showed no cotyledon damage in imbibition for 24 hour while large seed cultivars were damaged 78% of cotyledon, and black seed showed low cotyledon damage compared to yellow seed. Hypocotyl length was shorter in large seed rather than in small seed, but hypocotyl thickness in large seed was more thick than in small seed. In correlation coefficients, seed coat rate, embryo rate exhibited significantly negative association with seed weight, and the correlation of seed weight with water uptake in 3 hour after soaking was significantly negative, but in 24 hour showed positive correlation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.320-326
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• 2009

The crops showing hard seed character have high seed viability after seed storage for long period. The low germination rate due to hard seed coat, however, cause a problem of low seedling establishment in field condition. Three legumes used in the experiment, lablab bean (Dolichos lablab L.), asparagus bean (Vigna sesquipedalis L. Fruwirth), and soybean (Glycine max L. Merr.), showed low germination rate (26, 17, and 5%, respectively) due to thick and hard seed coat. In this study artificial treatment for breaking dormancy was tested in hard seeds. The effect of proper treatment was various depending on species. The germination rate of lablab bean was highly improved up to 94% by soaking into water for 24 hours. In the case of asparagus bean, the rate was increased up to 90% by soaking for eight hours near boiling water until it cools. The germination rate of small hard seed soybean was increase to 96% by soaking into concentrated sulfuric acid for 10 minutes. Ultrastructural change revealed by scanning electron microscope (SEM) reflects that the structure of micropyle was changed and water uptake was facilitated with all treatments tested in the experiment. Especially, sulfuric acid treatment resulted in the degradation of micropylar tissue. These results demonstrate that the artificial treatment including sulfuric acid and (hot) water soaking treatment for promoting water uptake can be applied to improve seed germination in legume seed with thick and hard seed coat.