• Journal of Life Science
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• v.22 no.9
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• pp.1166-1172
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• 2012

To investigate potential medicinal or functional uses of Eriobotrya japonica, this study focused on the isolation and identification of antioxidant compounds from Eriobotrya japonica leaves. Various solvents were extracted from the leaves, and their scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals was measured, in addition to their superoxide dismutase-like activity, polyphenol compounds, and flavonoid content. Ethyl acetate extract exhibited the strongest scavenging effect in a 0.2 mM solution of DPPH ($63.24{\pm}2.20%$, $81.83{\pm}2.10%$, and $93.15{\pm}2.31%$ in 0.3, 0.7, and 1.0 mg/ml sample concentrations, respectively). The antioxidant effect of the ethyl acetate extract and methanol extract were generally stronger than that of n-hexane extract. The extracts were further purified by repeated silica gel column chromatography. The antioxidant compounds were identified as phytol, ${\beta}$-sitosterol, and (-)-loliolide using GC/MS.

• Korean Journal of Medicinal Crop Science
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• v.27 no.2
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• pp.115-125
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• 2019

Background: Glycyrrhiza radix (licorice root) have been used as an oriental medicine material for long time, and its protective effects on oxidative stress, inflammation and cognition deficit have been recently reported. However, the cultivation of Glycyrrhiza species as medicinal crops is associated with some problems such as low productivity and early leaf fall, etc. To resolve this problems, Glycyrrhiza cultivars have been developed by direct hybridization of each Glycyrrhiza species by Korean researchers. The present study was conducted to compare the Glycyrrhiza cultivar radix (Dagam, Sinwongam and Wongam) for their anti-oxidation, anti-inflammation, and cognition improvement effects and levels of liquiritin, isoliquiritigenin and licochalcone in order to select an excellent cultivar as a material resource. Methods and Results: For evaluating the inhibitory efficacies of the Glycyrrhiza cultivar extracts on oxidative stress and inflammation in BV2 cells, we measured their reactive oxygen species (ROS) production and nitric oxide (NO) release after treating them with lipopolysccharide. The scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and peroxynitrite ($NOO^-$) radicals were evaluated. Cell proliferation and N-methyl-D-aspartate receptor (NMDAR) inhibition were analyzed. The total phenol, liquiritin, isoliquiritigenin and licochalcone A content in the extracts of the three culivars were quantified. Furthermore, the correlation coefficient between the activities and contents of total phenol, liquiritin, isoliquiritigenin and licochalcone A were also calculated. The results indicated that Sinwongam exhibited potent anti-oxidant, anti-inflammatory and NMDAR inhibititory activities. Sinwongam also showed higher total phenol and licochalcone A contents than the other cultivars. Among the three cultivars, Dagam exhibited a positive effects on NO release inhibition, cell proliferation and contents of liquiritin and isoliquiritigenin. Conclusions: Sinwongam is expected to be the most useful resource as a functional material for anti-oxidation/anti-inflammation and cognition improvement among the three studied licorice cultivars.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.225-233
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• 1978

Uptake and distribution of labelled urea, $NH{_4}^+$, and $NO{_3}^-$ by Tongil and Jinheung rice grown with each nitrogen source until ear formation stage under water culture system were as follows. 1. When the previous nitrogen source was same as one tested the uptake rate ($mg^{15}N/g$ d.w. root 2hrs, at $28^{\circ}C$ light) was great in the order of $NH_4$ >urea> $NO_3$ and higher (especially $NH_4$) in Tongil than in Jinheung. Rate limiting step (slowest) seems to be exist at R (root)${\rightarrow}$LS(leaf sheath) for urea, LS${\rightarrow}$LB(leaf blade) for $NH_4$ and M(medium)${\rightarrow}$R for $NO_3$. The fast step of translocation appeare to be at M${\rightarrow}$R for urea R${\rightarrow}$LS for $NH_4$ and LS${\rightarrow}$LB for $NO_3$. 2. The uptake rate of $NH_4$ by the urea-fed plant increased almost linearly from $18^{\circ}C$ via $28^{\circ}C$ to $38^{\circ}C$ in Tongil ($Q_{10}$=1.21 and 1.32 respectively) while no change in Jinheung ($Q_{10}$=0.99 and 1.00 respectively). It decreased by 12% in Jinheung under dark but uo change in Tongil. 3. The uptake rate of nitrogen source by different source-fed plant was great in the order of $NH_4{\rightarrow}^{15}NO_3$ $NO_3{\rightarrow}^{15}NH_4$, $urea{\rightarrow}^{15}NO_3$ and higher (especially $NH_4{\rightarrow}^{15}NO_3$) in Tongil. In the case of $urea{\rightarrow}^{15}NH_4$ it was same in $NH_4{\rightarrow}^{15}NO_3$ for Tongil and slightly lower than that in $NO_3{\rightarrow}^{15}NH_4$ for Jinheung. It was lower (especially Tongil) in $NH_4{\rightarrow}^{15}NO_3$ than in $NH_4{\rightarrow}^{15}NH_4 $ 4. The uptake rate (in $NH_4{\rightarrow}^{15}NO_3$) was higher during 15 minutes than during 2 hours and always higher in Tongil. 5. $^{15}N$ excess % and content in each part, and uptake rate of root seems to have their own significance relatling with metabolism and translocation respectively. The change of nitrogen nutritional environment and source preference of varieties were discussed in relation to field condition and efficient use of nitrogen fertilizer.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.303-308
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• 2016

This study was carried out to determine the effects of application levels of fertilizer and sowing methods on yields and nutritive values of Italian ryegrass (IRG) in early spring. Five fertilizer levels were used: Treatment 1, 100-80-80 kg/ha; Treatment 2, 120-100-100 kg/ha; Treatment 3, 140-120-120 kg/ha; Treatment 4, 160-140-140 kg/ha; Treatment 5, 140-120-120 kg/ha of $N-P_2O_5-K_2O$ with silicate fertilizer 200 kg/ha. Dry matter (DM) yield was 8,330 kg/ha in Treatment 5, 7,686 kg/ha in Treatment 4, and 7,347 kg/ha in Treatment 3. There was no significant difference in total digestible nutrients (TDN) content. The content of crude protein was the highest in Treatment 5. Dry matter ratio was the lowest in Treatment 5. In Treatment 3, DM yield was 7,347 kg/ha, when total amounts of fertilizers were applied at one time. However, DM yield was 7,405 kg/ha, when 50% of pre-planting fertilizer and 50% of supplementary fertilizer were applied at different time. There was no significant difference between total application and split application of fertilizers. However, DM yield was 9,469 kg/ha in application treatment with 100 kg/ha of additional urea at three to four leaf stages of IRG. Regarding DM yield by sowing methods of IRG, the following order was found: drill seeding (8,176 kg/ha) > rotary-broadcast seeding-stamping (7,957 kg/ha) > rotary-broadcast seeding (7,810 kg/ha) > broadcast seeding (7,347 kg/ha) > broadcast seeding-rotary (7,034 kg/ha). DM yield (59.57%) was the lowest in broadcast seeding-rotary. Crude protein content was the highest with rotary work but the lowest with broadcast seeding.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.82-86
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• 2015

This study was carried out to develop the silkworm rearing technique in unused mulberry leaves after harvesting mulberry fruit. The growth of Gwasang No. 2 and Suhyang was very good compared to control cultivar Chungil in leaves size and new branch growth, but new branch and leaves of Daeshim was similar or small to control cultivar Chungil. The number of leaves of Gwasang No. 2 and Suhyang was lower than Chungil, but weight of leaves per tree was heavyer than Chungil. Mulberry leaf yield was Gwasang No. 2 521 kg/10a, Suhyang 189 kg/10a, Daeshim 73 kg/10a, Chungil 1,095 kg/10a. Content of mineral element of all three mulberry cultivars leaf for mulberry fruit production was higher than Chungil in N, P, K, Ca etc. Feeding quantity of silkworm of Gwasang No. 2 and Suhyang was much more than Chungil. Feeding quantity was highest at Suhyang in 96 kg/box. Growth duration of silkworm larvae was not different in all four mulberry culivars but weight of silkworms (5th instar 3rd day) was heavy at Gwasang No. 2 (2.07 g/head) and Suhyang (2.11 g/head) compared to control cultivar Chungil (1.92 g/head). Mortality of silkworms was 14.6% (Gwasang No. 2), 13.3% (Suhyang), 13.9% (Daesim), 12.6% (Chungil) and than higher at elder instar stage. The production amount of silkworm (5th instar 3rd day) was 35.4 kg/box (Gwasang No. 2), 36.6 kg/box (Suhyang), 35.0 kg/box (Daeshim), 33.6 kg/ box (Chungil). Amount of possible rearing silkworms was estimated 3.4box/10 a (Gwasang No. 2), 1.3box/10a (Suhyang), 0.5box/10a (Daeshim), 8.7box/10a (Chungil).

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.3
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• pp.125-132
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• 1979

A field experiment was conducted to evaluate the effectiveness of an organic fertilizer (Glutamic acid fermentation by product ameded with nitrogen) on the growth and yield of radish and chinese cabbage on a relatively fertile soil. Additional laboratory studies were also made to find out the influence of mentioned fertilizer on the phisical and chemical characteristic of soils. The results are summarized as following. 1. Effect of fertilizer on the growth and yield. a. On a relatively fertile soil with high organic matter content (3%), the organic fertilizer was not effective for the growth and yield of radish and yield of radish and chinese cabbage. b. The application of organic fertilizer increased the K contents in plants both in radish and chinese cabbage. It was observed that the high content of K in radish leave lowered the leaf/root ratio and the leaf/root ratio showed a positive correlation with root weight. 2. Effect on soil physical and chemical properties. a. The application of organic fertilizer resulted in the improvement of soil physical property by lowering bulk density and increasing porosity. b. It was found that application of organic fertilizer increased the water stable soil aggregates. c. The application of organic fertilizer did not result in the significant increase in soil organic matter. d. Soil pH was lowered by the application of organic matter. It was speculated that the oxidation of ammonical nitrogen in the fertilizer is responsible for the lowering of soil pH.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.106-113
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• 2005

This study was carried out to develop a novel hydroponic medium far fruit vegetable crops by using waste synthetic fibers. In physical analysis of the synthetic fiber medium (SFM), the bulk density and percent solid phase were lower, while the porosity and water content were greater in comparison with the rockwool slab. The SFM had pH of 6.5 and EC of $0.03dS{\cdot}m^{-1}$ both of which are similar to those of the rockwool slab. The CEC of 0.39me/100mL of the SFM was lower than compared with 3.29me/100mL of the rockwool slab. However, concentrations K, Ca, Mg and Na were slightly higher in the SFM than those in the rockwool slab. The 'Momotaro' tomato crop in the SFM gave comparable plant height, stem diameter, days to first flowering, fruit weight and percent marketable yield as the rockwool slab. In the SFM and in the rockwool slab, mean fiuit weight were 182g and 181g, percent marketable yield were $93.8\%$ and $92.0\%$, respectively. The marketable yield per 10a in the SFM was 12,799 kg, which was $97\%$ of that in the rockwool slab. Growth parameters such as leaf length and width, leaf number, stem diameter and chlorophyll content of an exportable cucumber crop grown in the SFM and the rockwool slab were not different. Fruit weight was greater in the rockwool slab, while percent marketable yield was greater in the SFM. The marketable fruit yield per 10a of 5,062kg in the SFM was $2\%$ greater than that in the rockwool slab. $NO_3$ concentration in nutrient solution during the crop cultivation was higher in the SFM than in the rockwool slab, while concentrations $NH_4$, K, Ca, Mg and $SO_4$ were not different between the two media.

• Korean Journal of Environmental Agriculture
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• v.22 no.3
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• pp.185-191
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• 2003

The mechanism imparting salt tolerance to crop plants remains still unsolved, although soybean has been classified as a susceptible plant to NaCl. To determine optimum parameters on physiological responses for improving sensitivity of salinity in breeding program, soybean (Glycine max Merr., cv. "Gwan-gan") plants were grown in a greenhouse, treated 20 days after emergence for 7 days with NaCl at 0, 30, 60, and 90mM, corresponding to electric conductivity of 1.2, 4.4, 7.3, and 10.4 dS/m, respectively, and assessed 30 days after treatment. Chlorophyll contents were significantly decreased by NaCl ($0.4{\sim}1.0\;mg/g$) compared to control (1.2 mg/g). Photosynthesis rate by NaCl treatment at $0{\sim}90\;mM$ at flowering stage was ranged from 5.0 (control) to $9.6\;{\mu}mol/m^2/s$. Oxygen for respiration was consumed from 5.4 to $9.7\;{\mu}mol/m^2/s$ so that the ratio of $O_2$ (evolution:consumption) was increased with the increase of NaCl, indicating that $O_2$ consumption seems to go beyond $O_2$ evolution. Water potential of leaf at vegetative stage II was ranged from -0.6 to -1.8 MPa and the highest level was observed at mid-day. Water potential by salt stress was decreased with range of $-2.1{\sim}-2.7MPa$ compared to control. Transpiration was decreased from 17% to 20% by NaCl stress. Water vapor diffusing resistance of intercellular air space was affected significantly, increasing up to $16{\sim}24%$ compared to control by NaCl treatment. Salt-treated soybean tended to accumulate $Na^+$, specially in root, with reduced absorption of N, P, $K^+$, $Ca^{2+}$, and $Mg^{2+}$ contents. Free proline content of soybean leaf as affected by different NaCl concentrations was increased 4.2 times ($184{\sim}434\;{\mu}g/g$) more than control. NaCl also increased activities of nitrate reductase and peroxidase by $28{\sim}161%$ and $3{\sim}22%$, respectively. The results show that physiological characteristics of soybean plants during assay were useful as the best parameters of salt stress or salt tolerance test to improve sensitivity in screening and breeding program among cultivars or germplasms.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.328-332
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• 2007

This study was conducted to investigate the effects of high concentrations of salts in soil on the growth, yield, quality, photosynthetic rate, and mineral uptake of tomato ('House Momotaro') in pot cultivation. The growth of tomato such as plant height, top plant weight and root weight decreased as the concentrations of salts in soils increased. Yield decreased by 31% and 41% in EC 5.0 and $7.5dS{\cdot}m^{-1}$, respectively compared with the salt concentration of EC $1.5dS{\cdot}m^{-1}$. Yield reduction was caused by low mean weight and number of fruit if at high salt concentration in soil, and affected by low photosynthetic rate and water potential in leaf, The rate of blossom-end rot was highest (16.7%) in EC $7.5dS{\cdot}m^{-1}$ and increased as the concentrations of salts in soils increased. The contents of soluble solids and titratable acids showed a tendency to increase with increasing the concentrations of salts in soils. Photosynthetic rate, water potential and stomatal conductance in leaf decreased as the salt concentration in soil increased. The higher the salt concentration in soil, the lower the mineral uptake such as T-N, P, K, Ca and Mg but, the higher the content of Na.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.532-537
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• 2011

'Seolgaeng' is a new Japonica rice variety developed from an 'Ilpumbyeo' mutant line, N-methyl-N-nitrosourea (MNU) treatment on fertilized egg cell, by a rice breeding team of National Crop Experiment Station, Rural Development Administration in 2001. This variety has about 134 days of growth duration from transplanting to harvesting in central plain area of Korea, a good semi-elect plant type and resistant to lodging with strong culm. The number of panicles/hill of 'Seolgaeng' is more than that of 'Hwaseongbyeo'. The milled rice appearance of this cultivar is an opaque, but it has amylose content (19.3%) similar to 'Hwaseongbyeo'. It is superior to hypae formation of Aspergillus orzyae in the making of fermented rice and amount of pigmentation in fermented rice by Monascus anka that of 'Ilpumbyeo'. This variety showed slow leaf senescence and considerable resistance to viviparous germination. It is moderately resistant to leaf blast and susceptible to bacterial blight, virus disease and insect pests. The yield performance of this rice cultivar is about 5.27 MT/ha in milled rice in local adaptability test for three years from 1999 to 2001). 'Seolgaeng' is adaptable to central and southern plain areas of Korea.