• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.210-216
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• 2010

Rosa rugosa has traditionally been used as a folk remedy for diabetes. The objective of this study was therefore to demonstrate the inhibition of endothelial dysfunction activities through antioxidants and the anti-glycation of Rosa rugosa roots. Dried roots of Rosa rugosa were boiled in methanol for three hours, evaporated and lyophilized with a freeze-dryer. The methanolic extract of Rosa rugosa roots (RRE) was tested for antioxidant activities by measuring total polyphenol (TP) content, flavonoid content, 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging activity (DPPH) assay, and ferric-reducing antioxidant power (FRAP) assay. The total TP content, flavonoid content, FRAP value, and $DPPHSC_{50}$ are $345.2\;{\mu}g$ gallic acid equivalents/mg dry matter (DM), $128.1\;{\mu}g$ quercetin equivalents/mg DM, 2.2 mM $FeSO_4$/mg DM and $34.2\;{\mu}g$ DM/mL, respectively. Treatment of RRE significantly lowered fluorescent formation due to advanced glycation reaction. In addition, reactive oxygen species (ROS) scavenging assay, monocyte adherent assay and transendothelial electrical resistance (TEER) assay were performed to investigate the possibility that RRE improves endothelial dysfunction-induced diabetic complications. The adhesion of THP-1 to treated HUVEC with RRE ($100\;{\mu}g/mL$; 33% and $500\;{\mu}g/mL$; 75%) was significantly reduced compared to HUVEC stimulated by glyceraldehydes-AGEs (advanced glycation end product). The TEER value ($88\;{\Omega}{\cdot}cm^2$) of stimulated HUVEC by glyceraldehydes-AGEs was reduced compared to non-stimulation ($113\;{\Omega}{\cdot}cm^2$). However, normalization with RRE increased endothelial permeability in a dose-dependent manner ($100\;{\mu}g/mL$; $102\;{\Omega}{\cdot}cm^2$ and $500\;{\mu}g/mL$; $106\;{\Omega}{\cdot}cm^2$). Thus, these results suggest that Rosa rugosa roots could be a novel candidate for the prevention of diabetic complications through antioxidants and inhibition of advanced glycation end product formation.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.38-44
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• 2005

In addition to the variation in nitrate accumulation of vegetables due to environmental conditions, there is also a distinct genetic variation. The variation of nitrate accumulation in some cultivars of lettuce and spinach commonly cultivated in Korea was investigated. Ten cultivars for both lettuce and spinach were grown in plastic containers filled with a 1:1 mixture of perlite and vermiculite with application of Hoagland No. 2 nutrient solution of high nitrate content (17.3 mM N) in a greenhouse condition. Plants were harvested four weeks after transplanting four-leaf stage seedlings. Plant growth was measured by fresh and dry matter of shoot, and contents of nitrate and other inorganic ions and organic solutes including sugar, amino acids and organic acids were measured. Large and significant genotypical variations in the nitrate content of the plants were found for both lettuce and spinach, and high negative correlations between nitrate content and fresh or dry weight were found in lettuce and spinach. Variation in nitrate accumulation of lettuce and spinach cultivars was not directly related to the differences in contents of organic and inorganic solutes, and this result indicates that photosynthesis and osmotic regulation are not directly related with the nitrate accumulation. Considering the correlations between nitrate content and plant growth of this study, it can be simply suggested that different cultivars of lettuce and spinach have their own inherited growth and physiological characteristics and also optimum nitrogen level required for the growth. Therefore when available nitrogen in root media is higher than the optimum level required for the inherited growth potential, some of the excess nitrate supplied can be accumulated in plants.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.383-390
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• 2014

This study was conducted to investigate the growth characteristics of cucumber scion and pumpkin rootstock under different levels of light intensity (photosynthetic photon flux, PPF) and plug cell size in a closed transplant production system with artificial lighting. Cucumber scion and pumpkin rootstock seedlings were grown under the combinations of three levels of PPF (PPF 165, 248, and $313{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and five types of plug tray (50, 72, 105, 128, and 200 cells in the tray) for nine days. The shoot dry weight and relative growth rate increased with increasing PPF and plug cell size. As PPF increased, cucumber scion and pumpkin rootstock seedlings had higher dry matter, lower specific leaf area, and lower hypocotyl length. The first true leaf of cucumber scion and pumpkin rootstock unfolded at eight and seven days after sowing, respectively, except the treatment using 200-cell plug tray. The unfolding of first true leaf of seedlings grown in 200-cell plug tray was delayed by one day. Accordingly, it was considered that the use of small cell size such as 200-cell plug tray would require more time for the production of scion and rootstock. Based on the results, we suggest that cucumber scion and pumpkin rootstock be grown in 105-cell to 128-cell plug tray for eight days and 72-cell to 105-cell plug tray for seven days, respectively, when using splice grafting method with root-removed rootstock. Additionally, higher PPF is suggested to improve the growth and quality of scion and rootstock.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.227-234
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• 2017

This study aimed to investigate the nutrient solution developed by based on nutrient-water absorption rate of strawberry 'Maehyang' by comparing growth and yield for 8 months with 5 kinds of nutrient solution with different ion composition. Strawberry plants were planted at elevated bed and supplied with five kinds of nutrient solutions (RDA), Yamazaki, PBG, University of Seoul (UOS) and NewUOS from one month onwards. Five types of nutrient solution were supplied to the strawberry plants associated with EC $1.0dS{\cdot}m^{-1}$, pH 6.0, $150{\sim}300mL{\cdot}plant^{-1}$ per day. At 60 days after planting, leaf width and leaf petiole of the strawberry plants showed significant differences among nutrient solution types and photosynthesis was higher in RDA and NewUOS nutrient solution and lower in PBG nutrient solution. The EC of the drainage on vegetative growth stage was $0.7{\sim}0.8dS{\cdot}m^{-1}$, which is lower than the supplied EC level, and to $1.0-1.2dS{\cdot}m^{-1}$, afterwards. The pH of the drainage was higher in Yamzaki solution as 6.2~6.8, while the pH of the UOS nutrient solution was lower in 5.1~5.2. Nitrate content was most absorbed in vegetative growth stage and after flower clusters development. The potassium uptake was highest at the NewUOS followed by UOS and Yamazaki nutrient solution. At six months after -planting fresh weight and dry weight of shoot and root were higher in UOS and NewUOS nutrient solution than other nutrient solutions, and the dry matter ratio was lower at 43.5% in Yamazaki nutrient solution and 30.6% in NewUOS nutrient solution than other solutions. Length, width, weight, and sugar content of the strawberries harvested from December to February were unaffected by treatment, but yield was higher in NewUOS nutrient solution due to increasing fruit number and average weight. From March to May, number of fruit was higher in Yamazaki nutrient solution. In conclusion, there was no difference in the growth of 'Maehyang' when 5 nutrient solutions were grown under hydroponics. But in order to improve the marketability, the NewUOS nutrient solution is appropriate to use from planting to February and it is suitable to use Yamazaki nutrient solution after March when temperature is high and the amount of fruit set per inflorescence.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.66-77
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• 2019

The present study investigated pine trees, which forms a major plantation species in Korea, with the objective of improving the survival rate of pine trees after planting. Growth responses and characteristics were assessed by controlling the level of fertilizer application, which is a basic controlling the growth of pine seedlings, to identify the optimal fertilization treatment. Pine tree seedlings were grown in 104 containers and were examined 8 weeks after planting. Stem height and were measured at 4-week intervals. In terms of fertilization treatment for 1-0 pine seedlings, the treatment group with gradually-increasing fertilizer concentration ($500{\rightarrow}1000{\rightarrow}1000{\rightarrow}1000mg{\cdot}L^{-1}$) had the biggest increase in stem height and diameter at the root. The survey results indicated that the increased concentration treatment group and the gradually-increasing concentration treatment group had more growth compared with that in the fixed concentration treatment group. The gradually-increasing concentration treatment group ($500{\rightarrow}1000{\rightarrow}1000{\rightarrow}1000mg{\cdot}L^{-1}$) had the highest total dry matter production. Nine weeks after fertilization, the tips of the pine leaves turned yellow in the fixed concentration treatment group ($3000mg{\cdot}L^{-1}$). The same phenomenon was observed in the treatment group in which the concentration was increased to $2000mg{\cdot}L^{-1}$, and in the gradually-increasing concentration treatment group, when the concentration was raised up to $2000mg{\cdot}L^{-1}$. We concluded that the optimal fertilization conditions for producing healthy pine 1-0 seedlings involve fertilizing once a week with Multifeed 19 at $500mg{\cdot}L^{-1}$ during the seedling period, Multifeed 19 at $1000mg{\cdot}L^{-1}$ during the rapid growth period, and Multifeed 32 at $1000mg{\cdot}L^{-1}$ during the maturation period.

• Journal of Korean Society of Forest Science
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• v.64 no.1
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• pp.11-19
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• 1984

Potted, germinating Pinus rigida ${\times}$ P. taeda seedlings were inoculated with Pisolithus tinctorius (Pt) ectomycorrhizal fungus to test the effectiveness of Pt in relation to organic amendment and changes in soil fertility and soil texture. Pt was cultured as mycelia in vermiculite-peat moss mixture with nutrients and added to sterilized pot soils with or without organic amendment (fully fermented compost) at three soil texture levels (sand, loamy sand, and sandy loam) in a factorial design. Plants were grown in a greenhouse for 4 months and harvested to compare their growth with non-mycorrhizal plants and plants infected by natural fungi. Regardless of sod texture, soil fertility, or organic amendment, seedlings inoculated with Pt were better in dry weight and height than non-mycorrhizal plants or those infected by natural fungi. An exception was observed in the most fertile soil (0.075% N and 1.32% organic matter content in sandy loam with organic amendment), where non-mycorrhizal plants were slightly bigger (8%) and heavier (18%) than Pt-inoculated plants. In over-all average, Pt-inoculated seedlings were 30% taller and 107% heavier than those infected by natural fungi and 31 % taller and 60% heavier than non-mycorrhizal plants. Growth stimulation of seedlings by Pt was more pronounced in less fertile sand soil when organic was not amended. Mycorrhizal frequency of Pt (% of mycorrhizal root tips) was reduced to about half (from 84 to 33% in sandy loam and from 77 to 40% in loamy sand) by organic amendment, while that of natural fungi was not significantly affected. Severe nitrogen deficiency was observed in the needles of non-mycorrhizal plants (1.38% N), while both Pt-inoculated plants (1.68% N) and those infected by natural fungi (1.89% N) did not develop symptom, suggesting an active role of mycorrhizae in absorption of soil nitrogen. Top to root ratio increased with organic amendment to non-mycorrhizal plants, but was not significantly affected by fungal treatment. It was concluded from this study that relative effectiveness of Pt was determined by soil fertility. Organic amendment to less fertile sand soil increased effectiveness of Pt, while the same amendment to more fertile loamy sand and sandy loam decreased effectiveness of Pt. Benefits of Pt mycorrhizae would be expected most either when organic was not added to the soil, or when soil nutrients were not abundant.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.3
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• pp.165-172
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• 1973

The optimum time for nutritional diagnosis of the field-grown rice plant by total plant analysis, and the relationship between maximum or minimum nutrient content at various growth stages and corresponding yield and between maximum or minimum yield and corresponding nutrient content were as follows. 1. The percentage occurence of the minimum nutrient content in straw or grain of minus nutrient plot was in the order of 20 days after transplanting (20)>maximum tillering (MT)>harvested straw (HS)> earformation (EF)>straw at flowering (FS)>harvested grain (HG)>ear at flowering (FE) for nitrogen, MT>EF>HS>20=FS>FE>HG for phosphorus and MT>EF>20>FS>HG>FE for potassium. 2. The time when the occurece of minimum nutrient content in minus plot is highest was considered as the optimum time for nutritional diagnosis of root zone. It was 20 days after transplanting in N and maximum tillering stage in P and K. 3. The highest relative difference($100{\times}(L-H)/H$), between maximum (H)and minimum(L) nutrient content appeared in harvested straw for N and P while in harvested grain for K and Si, suggesting the close relation to their translocation from straw to grain. 4. The corresponding yield of maximum nutrient content was higher than that of minimum content at all growth stages in N, at all stages except MT and EF in P, at 20 days after trans planting and harvest in K, but it was always lower in Si, thus the contribution of nutrient content to yield will be in the order of N>P>K>Si. 5. The highest relative difference ($100{\times}(L-H)/H$, where H and L stand for yields) between yields corresponding to maximum and minimum nutrient content appeared at 20 days after transplanting for N. P. K, indicating the time of the closest relation between yield and nutrient content. 6. The highest difference (H-L, where H and L stand for nutrient content) between N. P. K contents corresponding to maximum or minimum yields came at 20 days after transplanting. The contents of N. P. K corresponding to the maximum total dry matter yield were lower than those corresponding the maximum grain yield at this stage. These facts support the closest relation between yield and nutrient content at this time. 7. The highest yield among yields corresponding to maximum nutrient contents occured at 20 days after transplanting in N. P. K but the lowest yield among yields corresponding to minimum nutrient contents appeared at the same stage only in nitrogen. 8. From the above facts the optimum time for diagnosis of nutrient around root zone seems different from that for diagnosis of nutritional status in relation to grain yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.3
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• pp.211-216
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• 2009

Approximately 43 million tons of livestock manure (LM) are produced each year on Korean farms. LM can be utilized as a valuable resource and/or it can contaminate water by runoff and leaching through the soil, when LM has been thoughtlessly applied to the land and directly discharged into the water. This experiment was carried out to investigate the effect of no-till system and LM application on dry matter (DM) yield of silage corn and $NO_3$-N concentration in leaching water of lysimeter installed in the experimental field. The treatments were replicated three times in split plot design. Main plots consisted of tillage systems, such as conventional tillage (CT) and no-tillage (NT). Sub plots consisted of the type of LM, such as chemical fertilizer (CF), composted cattle manure (CCM) and composted swine manure (CSM). The control plots were fertilized as commercial chemical fertilizer. DM yields of corn increased significantly in order to CF > CCM > CSM (p<0.05). DM yield of corn in CT increased as comparing with that of corn in NT. Plant height, ear height and stem diameter also increased in order to CF > CCM > CSM. In addition, the root weight in CT was increased as comparing with that of corn in NT. However, there was no interaction effects of between type of LM and tillage system. $NO_3$-N concentration in leaching water of LM application was less than 10 ppm, but $NO_3$-N concentration in CF exceeded 10 ppm which is safety level of drinking water during summer time (rainfall season).

• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.1
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• pp.35-40
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• 1983

This study was conducted to investigate the effect of some kinds of tree litters covered the soil surface on the germination, establishment, sward composition, and herbage production of the grasses sown by the oversowing method. The litters were leaves of Pinus rigida Miller, Quercus variabilis Blume, Larix leptolepis Gord, and Alnus hirsuta Rupr. The results obtained were as follows; 1. In the Petri dish, germination was affected by grass species and kinds of litters, especially the percolate from Pinus litter seriously suppressed the early germination of small size seeds such as ladino clover and timothy. 2. In the pot, establishment was slightly suppressed in ladino and timothy by the percolate from Pinus litter, while in others it was decreased relatively. 3. Among the 6 species investigated, the small size seeds of ladino clover and timothy and the large size seeds of red clover, they could be early put into the litter spaces and established well. 4. In Larix litter, the establishment percentage of all species were decreased seriously owing to low moisture retention capacity. 5. Grass height and root length were different in kinds of litters and species. 6. The percentages of establishment on each surface treatments of burning, treading, raking, and the control under Quercus tree were 36, 46, 37, and 31%, respectively. 7. The sward percentage of oversown grasses and legumes was 57.8% in burning, 70.9% in treading, 59.6% in raking, and 54.0% in the control. 8. Treading treatment was most effective to destroy existing vegetation and improve soil-seed contact when oversowing and showed the best result. 9. Yield of dry matter per unit area in treading treatment was higher (p<0.05) than those of the other treatments. The above experimental results suggest the importance of direct oversowing on the litters in the mountainous land and forest land.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.69-76
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• 1991

A pot experiment was conducted to find out the effects of lime and phosphate application on the changes of number of soil microorganisms, indigenous Rhizobium japonicum, nodule formation, and ureide-and amide-N in leaf and stem exudate of soybean plant under uncultivated hillside red earth in very low pH value, organic matter, available phosphate, and cation exchange capacity. The results obtained were summarized as follows : 1. The plant height, stem length, root dry weight and nodule weight were significantly increased with the application of lime and phosphate application than that of control plot. 2. The concentration of amide-N in soybean plant at the 45 days after sowing was obtained as high in order of control>lime> lime+phosphate while the concentration was obtained in order of Iime+phosphate>lime> control at flowering stage 3. However, concentration of ureide-N in the soybean leaf at the 45 days after sowing was obtained as high in order of control>lime>lime+hosphate while reversed concentration was obtained in stem. 4. The number of soil microorgan isms were increased with increase of pH value, available phosphate and soil exchangeable cation. 5. Significantly negative high correlation were obtained with the concentration of Al, Fe in soil and the concentration of amide-and ureide-N in soybean plant at flowering stage while positive correlation was obtained with plant growth and the concentration of ureide-N.