• Applied Microscopy
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• v.37 no.2
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• pp.83-91
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• 2007

The present study examined the epidermal changes of adhesive disks which occur during attachment in Parthenocissus tricuspidata using scanning and transmission electron microscopy. Several adhesive disks, each covered with a bract, develop from the shoot apical meristem during early development. In the initial stage, the adhesive disks are club-shaped and their upper and lower epidermis are indistinguishable. However, in the actively growing stage, they become spherical and both epidermis are clearly differentiated into the adventitious roots. Prior to wall attachment, the adhesive disks exhibit adaxial convex and abaxial concave shapes, and electron-dense substances are abundant in the vacuoles of epidermal cells. The peripheral area of the adhesive disk is adhered first to the wall surface, while the central area is drawn inward in a vacuum-like state during attachment. As the attachment progresses and the electron-dense substances continue to discharge, the upper and lower epidermis rapidly undergo deterioration and the disks shrink considerably. At this stage, structural changes of the lower epidermis occur much faster than in the upper one. The discharged substance is accumulated on the wall surface, and this aids the attachment of adhesive disks on the wall for long periods. In this manner, the shape and structure of the adhesive disk epidermis change drastically from initial growth to the mature stage. Further, the role of electron-dense substance and shrinkage of the disk during attachment has been discussed in Parthenocissus tricuspidata.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.190-197
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• 2010

To develop the safe and natural antimicrobial agents, the 68 ethanol extracts from the 61 different kinds of oriental herbal medicine were prepared and their antimicrobial activities were evaluated. The herbal medicine used were from China (46 kinds), South Korea (14 kinds), North Korea (5 kinds) and Vietnam (3 kinds), respectively, and the root (27 species) was popular part in this study. The average water content and extraction ratio for ethanol were 7.10% and 6.75%, respectively. Determination of antimicrobial activity by disc-diffusion assay at 0.5 mg/disc concentration showed that the extract of Angelica tenuissima Nakai (china), Illicium verum, Junci medulla, Rhus javanica L., Salvia miltiorrhiza Bunge and Syzygium aromaticum has strong antimicrobial activities against different food spoilage and pathogenic bacteria and fungi. Determination of MIC and MBC/MFC further showed that the extract of Syzygium aromaticum has MIC of 1.25 mg/mL and MBC/MFC of 1.25~5.00 mg/mL against Listeria monocytogenes, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, Salmonella typhimurium, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Saccharomyces cerevisiae. And, the extract of Junci medulla, Rhus javanica L. and Salvia miltiorrhiza Bunge showed strong antibacterial activities with MIC of 0.08~0.63 mg/mL and MBC/MFC of 0.08~2.50 mg/mL against the tested bacteria except E. coli and P. aeruginosa. In a while, the results of hemolytic activity of 68 different herbal extracts against human red blood cells showed that the extract of Angelica tenuissima Nakai has hemolytic activity at 0.5 mg/mL concentration. Therefore, Illicium verum, Junci medulla, Rhus javanica L., Salvia miltiorrhiza Bunge and Syzygium aromaticum were finally selected for natural antimicrobial resources. Further research on active substances and the mode of action of the selected herbal medicine is necessary.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.275-280
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• 2011

BACKGROUND: The present study was conducted to find out the suitable method for organic rice production on the basis of different seedling raising methods at nine eco-friendly agricultural units of Samgi, Mangsung, Iksan and Sungsan, Gusan of Jeollabuk-do, during 2009-10. METHODS AND RESULTS: On the basis of yield and physiological parameters, pot seeding method was found to be superior to drill seeding and broadcast seeding methods. The number of panicle, grain, the precent of ripened grains, and the 1,000 grain weight, were better in pot seeding method. Maximum yield and other attributes were recorded in rice, cultivated with seedlings raised by pot and broadcast seeding method. Number of panicle/hill and grain/panicle was 10.4% and 35.1% higher than the broadcast seeding method, respectively. Yield also showed 8.8% increase in pot seeding method as compare to broadcast seeding method. Higher grain yield was obtained when 56 hills/$3.3m^2$ of rice seedlings were used as compare to 50 hills/$3.3m^2$ raised by pot seeding method and 70 hills/$3.3m^2$ of broadcast seeding method. Lodging was minimum in seedlings raised with pot seeding method as thickness of third internode was more (9.0%) than the seedlings, raised with broadcast seeding method. Root length and dry weight also showed similar tendency i.e. 13.8% and 25.3% higher, respectively. CONCLUSION(s): Quality and grade of rice, cultivated with pot seeding method was better than broadcast seeding method. Head rice was 4.4% higher; and protein content and broken rice grown by pot seeding method were 0.4% and 1.8% lower than broadcast seeding method, respectively.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.89-94
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• 2005

This study was conducted to investigate the effect of nonwoven fabrics weight(Ounce) on growth, quality and yield of oriental melon (Cucumis melo L. var. makwa Mak.). Seedling of 'Gumssaragi-Eunchun' was grafted on 'Shinthozoa' root stock. In this study, The minimum air temperature in 6 ounce at night was $4.8^{\circ}C,\;6.9^{\circ}C$ in 9 ounce, $7.9^{\circ}C$ in 12 ounce and $8.0^{\circ}C$ in 15 ounce, respectively. Leaf length, stem diameter, leaf numbers, leaf area, fresh weight and dry weight for 30 days after planting were better in high minimum air temperature at night than in low minimum air temperature, particularly leaf areas of the plant in 9 ounce was $370cm^2$ at 30 days after planting, $116\%$ in 12 ounce, $129\%$ in 15 ounce. The xylem exudates amount in 9 ounce for 24 hours just after basal stem abscission was 10.1mg. It was 1.2 times much in 12 ounce and 1.9times much in 15 ounce than in 9 ounce at 30 days after planting. The blooming of female was faster by 6 days in 15 and 12 ounce but was delayed by 3 days in 6 ounce than 9 ounce, and the days of blooming to harvesting were shorter by 3 days in 15 ounce and 4 days in 12 ounce but was delayed by 3 days in 6 ounce than in 9 ounce. Fruit weight, fruit length, fruit diameter, flesh thickness, soluble solids, and total yield was the highest in 15 ounce followed by 12 ounce,9 ounce and 6 ounce. Fermented fruit rate was the highest in 6 ounce followed by 9 ounce, 12 ounce and 15 ounce, and marketable fruit rates were 15, 12, 9 and 6 ounce in order. Compared to 1,781kg yield per 10a of 9 ounce, $19\%\;and\;49\%$ was increased under 12 ounce and 15 ounce but $47\%$ were decreased 6 ounce.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.176-181
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• 2003

The leaching behaviour of [aniline-$^{14}C$]mefenacet in soil was investigated using glass columns (5 cm I.D. $\times$ 30 cm. H) packed with two types of soils with different physicochemical properties. $^{14}C$-Mefenacet (8.33 kBq) and mefenacet (in total, 1.05 mg/kg) were treated onto soil columns and rice plants (Oryza sativa L.) were grown for 17 weeks on these columns. Leachates from the columns were collected at the rate of 122.5 mL per week. $^{14}C$-Activities leached from soil A (OM, 3.1%; CEC, 86 mmol(+)/kg; texture, loam) columns with and without rice plants were 1.95 and 4.19% of the originally applied, whereas those from soil B (OM, 1.3%; CEC, 71 mmol(+)/kg; texture, loam) were 2.69 and 7.05%, respectively. These results indicated that larger amounts of $^{14}C$ were percolated from soil B with less organic matter and from the columns without vegetation. $^{14}C$-Activities absorbed by rice plants from soil A and B were 8.95 and 8.47%, respectively, most of which remained in the root and shoot excluding unhulled grains and ears without grains. $62\sim73%$ of the originally applied $^{14}C$ remained in the depth of $0\sim5cm$ in soil. The mass balance indicated that the losses by volatilization and/or mineralization amounted to $3.4\sim9.2%$ of the originally applied. $^{14}C$-Radioactivities in the aqueous phase of the leachates ranged from 59.4 to 97.7% of the radioactivities in leachates, showing the fast transformation of mefenacet to the polar metabolites.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.344-350
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• 2006

An Antiviral producing bacterial strain was isolated from ginseng root environment in Hongcheon, Kangwon province of Republic of Korea. Identification of this bacterial strain was performed by physiological and biochemical tests along with 16S rRNA analyses. The results revealed that the bacterium was closer to genus Serratia, which was named as Gsm01. The strain was grown in Mannitol-Glutamate-Yeast (MGY) broth for 48 h. The culture was centrifuged and the filtrate obtained was tested for its ability to control Cucumber mosaic virus strain Y (CMV-Y) in greenhouse and field experiments. In the green house experiments, CF was evaluated for its ability to protect local host, Chenopodium amaranticolor and systemic host of CMV, Nicotiana tabacum cv. Xanthi-nc. It was found that, CF treatment reduced viral infection by 98% in local host; C. amaranticolor. The N. tabacum cv. Xanthi-nc plants treated with CF did not show visible viral symptoms 15 days post inoculation (dpi) and remained symptomless throughout the periods of the study. To evaluate effectiveness of CF under field conditions, experiment was carried out in a polyvinyl house. It was observed that, 52% plants were protected from viral diseases compared to non-treated plants, increasing the crop yield. This is the first report showing antiviral activity of a Serratia spp. against CMV.

• Magazine of the Korean Society of Agricultural Engineers
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• v.11 no.2
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• pp.1651-1660
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• 1969

The purpose of this study is to find out the reasonable amount of evapo-transpiration required for the paddy rice plant during the whole growing season. So. On the basis of the experimental data concerning the evapo-transpiration form 1966 to 1968, the author obtained the follow results. 1) The leaf area index in the densely planted plo is generally higher than that in the conventionally planted one during the first half of growing season So, the coefficient of transpiration in the former plot is somewaht higher than in the latter, and the coefficient of water surface evaporation under the plant cover has the inverse relation between both plots. 2) It is unreasonable that coefficient of evapo-transpiration is applied to the calculation of the evapo-transpiration requirements of each growing stage, because a degree of variation in meteorological factors and in the thickness of the plant growth is involved in it. 3) It is most reasonable that the rate of transpiration and of the water surface evapoation is applied to the calculation of the transpirated amount and evaporated one in each growing stage, because it shows almost constant value in spite of any meteorological conditions in so far as the variety of rice, planted density and control of applying fertilizer are sanme and the disease and blight are negligible. 4) The ratio of the amount of transpiration to the weight of the whole air dried yields has the tendency of decreasing as that of the yields increases having almost constant value despite the amount of pan evaporation; and the value is about 210 when the weight of root parts is included to that the yields. 5) Although the required amount of transpiration during the whole growing season can be calculated with the above ratio, Fig. 7 showing the relation between the amount of transpiration and the weight of the yields is more reasonable and will be convinient to find it. And the requirements of water surface evaporation during the same season can also be directly found witht theweight air dried straw refering to Fig. 8.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.183-189
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• 2000

This study was carried out to analyze ecophysiological responses for seedling of Quercus serrata, Quercus mongolica and Quercus variabilis that are the typical species of deciduous broadleaved forests in Korea. And executed experiments in the climatic control room to provide necessary information to ecological forest management and methods of natural regeneration through the analysis of seedling responses. The details of experimental analysis were growth processes of 4 months after seeding that vary with the condition of three light intensity[relative light intensity(RLI) 8%, 20%, 52%] and three soil moisture[water suction(WS) Ψ=100 hPa, Ψ=280 hPa, Ψ=330 hPa] gradient, growth factors after harvesting and the nutrition condition of leaves. The results of this study are followings: 1) Early growth was prosperous after germination for the species which have more weight of acorn. 2) The formation of lammas shoot was favourable with Q. variabilis and Q. mongolica. And the rate of the occurrence was the highest in the RLI 20%, and it was remarkably reduced in the RLI 8%. 3) As the height growth of seedling of all 3 species were greater in the RLI 20% and 8% than that of the RLI 52%, they showed strong shade tolerance. 4) The increase of light intensity promoted the diameter at root collar growth, and development of main and lateral roots with all 3 species. 5) It showed that the increase of light intensity in the experimental radiation condition raised special leaf area weight(mg/cm$^2$) and leaf area productivity(mg/cm$^2$). Consequently, these resulted in the increase of leaf thickness and total dry biomass per the unit area of leaf. 6) As the increase of light intensity, the minerals contents of leaves such as N, P and K were lowered, and the increase of soil moisture resulted in the increase of P, K, Ca and Mg.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.3
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• pp.115-122
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• 2011

The impacts of elevated temperature and $CO_2$ were studied on the seedlings of Maackia amurensis and Viburnum opulus var. calvescens. The seedlings were grown in controlled-environment growth chambers with four combinations of temperature and $CO_2$ treatments: $25^{\circ}C$ + ambient $CO_2$ (400 ppm), $25^{\circ}C$ + elevated $CO_2$ (800 ppm), $30^{\circ}C$ + ambient $CO_2$ (400 ppm), and $30^{\circ}C$ + elevated $CO_2$ (800 ppm). Under elevated temperature and $CO_2$ concentration, the dry weight decreased in seedlings of M. amurensis, but increased in seedlings of V. opulus var. calvescens. In addition, the shoot to root (S/R) ratio in M. amurensis reduced but that of V. opulus var. calvescens increased under elevated $CO_2$ concentration. The S/R ratios of two tree species increased under higher temperature. M. amurensis represented lower carboxylation efficiency under higher temperature and $CO_2$ concentration and that of V. opulus var. calvescens showed lower values under the only higher temperature. Photosynthetic pigment content of in the leaves of M. amurensis was lower under higher $CO_2$ concentration and higher under the increase of temperature, but that of V. V. opulus var. calvescens decreased according to the increase of temperature. Chlorophyll a/b ratios of M. amurensis and V. V. opulus var. calvescens decreased obviously with the increase of $CO_2$ concentration and temperature, respectively. In conclusion, the growth and physiological responses under the environmental changes such as temperature and $CO_2$ concentration depend on the tree species. Therefore, more studies are needed to predict the response of each tree species against the climate changes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.57-67
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• 2020

Pinus densiflora is the most widely distributed tree species in South Korea. Its ecological and socio-cultural attributes makes it one of the most important tree species in S. Korea. In recent times however, the distribution of P. densiflora has been affected by dieback. This phenomenon has largely been attributed to climate change. This study was conducted to investigate the responses of growth and physiology of P. densiflora to drought and nitrogen fertiliz ation according to the RCP 8.5 scenario. A Temperature Gradient Chamber (TGC) and CO₂. Temperature Gradient Chamber (CTGC) were used to simulate climate change conditions. The treatments were established with temperature (control versus +3 and +5℃; aCeT) and CO₂ (control: aCaT versus x1.6 and x2.2; eCeT), watering(control versus drought), fertilization(control versus fertilized). Net photosynthesis (P_n), stomatal conductance (g_s), biomass and relative soil volumetric water content (VWC) were measured to examine physiological responses and growth. Relative soil VWC in aCeT significantly decreased after the onset of drought. P_n and g_s in both aCeT and eCeT with fertiliz ation were high before drought but decreased rapidly after 7 days under drought because nitrogen fertilization effect did not last long. The fastest mortality was 46 days in aCeT and the longest survival was 56 days in eCeT after the onset of drought. Total and partial biomass (leaf, stem and root) in both aCeT and eCeT with fertiliz ation were significantly high, but significantly low in aCeT. The results of the study are helpful in addressing P. densiflora vulnerability to climate change by highlighting physiological responses related to carbon allocation under differing simulated environmental stressors.