• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.353-359
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• 1988

Variations in photosynthetic capacities of leaves differing in thickness were explained on the basis of relationships between gas exchange and internal leaf structure. The relative importance of gas diffusion and of biochemical processes as limiting for leaf photosynthesis was also determined. Mesophyll cell surface was considered to be the limiting internal site for gas diffusion. and cell volume to be indicative of the sink capacity for CO$_2$ fixation. Increases in cell surface area were assumed to reduce proportionately mesophyll resistance to the liquid phase diffusion of CO$_2$. Increased cell volume was thought to account for a proportional increase in reaction rates for carboxylation, oxygenation. and dark respiration. This assumption was tested using chamber-grown Glycine max (L.) Merr. cv. Amsoy plants. Plants were grown under 200, 400, and 600 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR to induce development of various leaf thickness. Photosynthetic CO$_2$ uptake rates were measured on the 3rd and 4th trifoliolate leaves under 1000 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR and at the air temperature of 28 C. A pseudo -mechanistic photosynthesis model was modified to accommodate the concept of cell surface area as well as both cell volume and surface area. Both versions were used to simulate leaf photosynthesis. Computations based on volume and surface area showed slightly better agreement with experimental data than did those based on the surface area only. This implies that any single factor, whether it is photosynthetic model utilized in this study was suitable for relating leaf thickness to leaf productivity.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.135-138
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• 2002

Cotyledonary explants from immature zygotic embryos of each 85 recombinant inbred lines (RILs) were cultured on medium containing MS salts, B5 vitamins, 40 mg$^{-1}$ 2,4-dichlorophenoxyacetic acid and 30 g$^{-1}$ sucrose. Frequency of somatic embryo formation on cotyledonary explants showed in thirty-six lines(＜10%), in thirty-seven lines (11~49%), in nine lines (50~89%), and in three lines(>90%), respectively, The highest frequency (up to 90%) and number (6.36 per cotyledon) of somatic embryos were obtained from lines of KM1010, KM1032 and KM1064. Primary somatic embryos produced from three lines produced numerous secondary somatic embryos on the surfaces, which were subcultured for over one year. Upon transfer to maturation and conversion medium (Komatsuda, 1992), somatic embryos converted to plantlets at a frequency of approximately 25%.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.13-17
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• 1985

Rhizobium japonicum isolates from all around Korea could be classified into two groups, i.e., acid producing fast-growers with 2.4 hour mean generation time and non-acid producing slow-growers in yeast extract-mannitol medium with 13.1 hour mean generation time. Tested fast-growers were higher in 6-phosphogluconate dehydrogenase activity than slow-growers were and used sucrose as carbon source whereas slow-growers did not. Fast-grower R4, R257, R278, showed tolerance even in 0.5M NaCl or above and the growth of all the strains tested were inhibited at below pH 4.5. Relative symbiotic activities of nitrogen fixation for these isolated with Glycine max cv. Jangyeobkong (commercial soybean cultivar mostly cultivated in Korea) ranged 0.1 to 2.0 comparing to that of R. japonicum L-259 (NRRL), without regard to their growth rate.

• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.1-5
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• 2009

Crude saponin, extracted from the starfish Asterias amurensis, was assessed for its capacity as a biological pesticide. As part of this analysis, its insecticidal and repellent activities, in addition to its acute and chronic toxicities were tested. In comparison with the control group, insecticidal activity of saponin against tobacco cutworm, Spodoptera litura, in kale, Brassica loeracea was low at 36.4%. Repellent activities of the extracted saponin against green peach aphid, Myzus persicae, and S. litura, on soybean leaf, Glycine max and kale were 65.6% and 35.0% at $1^{st}$ day, and 54.5% and 30.0% at $3^{rd}$ day, respectively. Acute and chronic toxicity analysis was carried out using acute immobilizatioin test and reproduction impairment test, respectively. The saponin had 48 h-$EC_{50}$ of $65.21{\mu}g/mL$. Twenty-one day accumulative reproduction after treatment was lower in Daphnia magna at $7{\mu}g/mL$ saponin (78 youngs), compared with the control group (129 youngs). These results indicate that the extracted saponin exhibited some toxicity and has potential as a repellent against insects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1700-1707
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• 2015

The effects of drying temperature on drying characteristics of soybeans with different grain sizes [6.0 (S), 7.5 (M), and 9.0 mm (L) (${\pm}0.2$)] with 25.0% (${\pm}0.8$) initial moisture content were studied. Drying temperatures varied at 25, 35, and $45^{\circ}C$, with a constant air velocity (13.2 m/s). Thin-layer drying models were applied to describe the drying process of soybeans. The Midilli-Kucuk model showed the best fit ($R^2$ >0.99). Based on the model parameters, drying time to achieve the target moisture content (10%) was successfully estimated. Drying time was strongly dependent on the size of soybeans and the drying temperature. The effective moisture diffusivity ($D_{eff}$) was estimated by the diffusion model based on Fick's second law. $D_{eff}$ values increased as grain size and drying temperature increased due to the combined effect of high temperatures and high drying rates, which promote compact tissue. Deff values of S, M, and L estimated were in the range of $0.83{\times}10^{-10}$ to $1.51{\times}10^{-10}m^2/s$, $1.17{\times}10^{-10}$ to $2.17{\times}10^{-10}m^2/s$, and $1.53{\times}10^{-10}$ to $2.95{\times}10^{-10}m^2/s$, respectively, whereas activation energy ($E_a$) based on drying temperature showed no significant differences in the size of soybeans.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.73-84
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• 1985

25 tank-mixed combinations between Haloxyfop-methyl at 0, 0.05, 0.1, 0.15 and 0.2 kg ae/ha and Acifluorfen at 0, 0.082, 0.163, 0.245 and 0.326 kg ai/ha were applicated at post-emergence on the late-season cropped soybean(Glycine max) fields predominated by grasses and assessed on the weeding efficacy. A most abundant weed species on the experimented fields were found at September (25 species). The broadleaved weed species and sedges were successively and proportionately emerged by the control rate of grass species. From the mono-treatment of each herbicide, Haloxyfop-methyl was recognized as a highly selective one between grasses and soybean, and Acifluorfen between broadleaf weeds and soybean, respectively. By combined application with both herbicides a synergistic weeding efficacy was detected on total weed species, however antagonistic or additive on each weed groups. Among other traits of soybean, stem dry weight was influenced by weed competitions during October, number of pods per plant during August and seed yields during whole periods. For most effective and reasonable weeding, no less than 0.4 kg ai/ha of each herbicides should be applicated in combinations.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.344-347
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• 2006

Watering methods for soybean sprouts could be mainly divided into two groups of overspraying and underwatering. The study was carried out to determine the effect of water supplying method on growth, morphological characteristics, colour and cutting resistance of soybean (cv. Junjery) sprouts and culture temperatures. The morphological characters, fresh and dry weights were measured on the 6th day after their culture, but daily mean temperatures inside the plastic culture boxes were measured by data-loggers. Lateral roots were more formed in the underwatering method (UM) than in the overspraying method (OM). Although their total lengths of both methods were nearly same, OM had longer hypocotyl but UM did longer root than the other. Middle and upper parts of hypocotyl were more thickened in UM than in OM. UM showed more hypocotyl fresh and dry weights than OM. There was, however, no significant difference between the two methods in cotyledon, root, total fresh and dry weights although the culture temperature was higher in OM than in UM.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.253-260
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• 2010

Plant secondary metabolites have always been a focus of study due to their important roles in human medicine and nutrition. We transferred the isoflavone synthase (IFS) gene into soybean [Glycine max (L.) Merr.] using the Agrobacterium-mediated transformation method in an attempt to produce transformed soybean plants which produced increased levels of the secondary metabolite, isoflavone. Although the trial to produce transgenic plant failed due to unestablished hygromycin selection, transformed callus cell lines were obtained. The induction rate and degree of callus were similar among the three cultivars tested, but light illumination positively influenced the frequency of callus formation, resulting in a callus induction rate of 74% for Kwangan, 67% for Sojin, and 73% for Duyou. Following seven to eight subcultures on selection media, the isoflavone content of the transformed callus lines were analyzed by high-performance liquid chromatography. The total amount of isoflavone in the transformed callus cell lines was three- to sixfold higher than that in control callus or seeds. Given the many positive effects of isoflavone on human health, it may be possible to adapt our transformed callus lines for industrialization through an alternative cell culture system to produce high concentrations of isoflavones.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.80-87
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• 2009

Aiming at development of region specialized crop, this study was conducted to clarify variety and cultivation region dependent on antioxidative compounds in black soybean seeds. For this purpose two black soybean varieties (Ilpumgeomjeongkong and Cheongjakong) were cultivated in 3 different regions (Hwaseong in Gyeonggido, Naju in Jeollanamdo and Jinju in Gyeongsangnamdo) in 2004 and 2005, and harvested seeds were used for isoflavone, anthocyanin and tocopherol contents along with electron donating ability-based antioxidative activities measurements. 100 grain weight between two varieties were not significantly different, but Hwaseong district showed higher 100 grain weight compared to Jinju and Naju. Ilpumgeomjeongkong was higher total isoflavone content ($1,064.9{\mu}g/g$) compared to Cheongjakong ($801.3{\mu}g/g$) in 2004, whereas Cheongjakong showed higher in 2005 compared to Ilpumgeomjeongkong. The highest isoflavone content was obtained in Hwaseong district in 2004, whereas it is the reverse in 2005 that Jinju district showed the highest isoflavone content. In total anthocyanin content, Ilpumgeomjeongkong (7.22 mg/g) was higher than that of Cheongjakong (6.83 mg/g), and Jinju district showed the highest total anthocyanin content (9.16 mg/g) compared to Naju and Hwaseong cultivating districts in their three cultivating districts. Total tocopherol content showed no significant difference between two varieties, but Hwaseong ($217.2{\mu}g/g$) and Jinju ($216.3{\mu}g/g$) districts showed higher content compared to Naju ($189.7{\mu}g/g$) among three cultivating districts. In tocopherol content ratio, $\gamma$-tocopherol was the highest from 56.2% to 59.9%. In electron donating ability (EDA) between two cultivars, Ilpumgeomjeongkong was significantly higher than Cheongjakong, and Naju was the highest of 55.6% among three cultivating districts.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.21-27
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• 2008

Germination of soybean and growth of its sprouts should be affected by storage condition and period of seeds. The experiment was conducted to examine the effects of period stored at cold room and storage conditions on their growth and morphological characters. The seeds, cv. Pungsannamulkong, were stored at $3^{\circ}C$ for 1 or 2 years, and by the three different storage methods of indoor, cold room, or transfer of indoor to cold room. Compared to the seeds stored for 2 years, one-year seeds had higher rate in hypocotyl of longer than 7 cm, root and hypocotyl lengths, and more hypocotyl fresh weight although there was not significant difference in total fresh weight. In the storage method experiment, one-year seeds stored at cold room and by transfer of indoor to cold room showed better growth, more lateral roots and fresh weights, although only two-year seeds stored at cold room did the same response, indicating that growth of soybean was affected by period and method of seed storage.