• Korean Journal of Medicinal Crop Science
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• v.13 no.3
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• pp.93-100
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• 2005

This research was performed to investigate the possibilities of industrial usage of camellia (Camellia japonica L.) by examining the antioxidant and antimicrobial effects of methanol extract with different sections. Content of total phenolics, DPPH radical scavenging activities and antibacterial activity of young leaf, mature leaf, flower bud, flower, bark, and seed of camellia were compared in vitro experimental models. Total phenolics was contained the higher in young leaf (74.62 mg), flower bud (65.02 mg) and flower (62.42 mg) but less than 20.95 mg per 100 g of dry weight in other parts of Camellia japonica L. And effects of antioxidant measured by DPPH radical scavenger activity ($RC_{50}$, reduce concentration 50%), was shown higher $7.16{\sim}18.14\;{\mu}g/m{\ell}$ in methanol extract of young leaf, flower bud and flower than $61.23\;{\mu}g/m{\ell}$ of BHT as a chemical oxidant. Also, the antimicrobial activity of Camellia japonica L. extracts determined using a paper disc method against food-borne pathogen and food spoilage bacteria, the young leaves extracts showed the most active antimicrobial activity against 7 kinds of harmful microorganisms. Flower bud extracts showed the highest antibacterial activity against P. aeruginosa and Enterobacter spp. C1036. In addition, the minimum inhibitory concentration (MIC) of young leaf extract against B. subtillis,S. fradiae,S. aureus,E. coli,P. aeruginosa, Enterobacter spp. C1036, and S. typhimurium were revealed 1 to 15 ${\mu}g/m{\ell}$. As a result, antimicrobial activity of camellia extracts was shown higher gram positive bacteria than gram negative bacteria.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.190-198
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• 2006

Radiation use efficiency (RUE), the amount of biomass produced per unit intercepted photosynthetically active radiation (PAR), constitutes a main part of crop growth simulation models. The objective of the present study was to evaluate the variation of RUE of rice plants under various nitrogen nutritive conditions. from 1998 to 2000, shoot dry weight (DW), intercepted PAR of rice canopies, and nitrogen nutritive status were measured in various nitrogen fertilization regimes using japonica and Tongil-type varieties. These data were used for estimating the average RUEs before heading and the relationship between RUE and the nitrogen nutritive status. The canopy extinction coefficient (K) increased with the growth of rice until maximum tillering stage and maintained constant at about 0.4 from maximum tillering to heading stage, rapidly increasing again after heading stage. The DW growth revealed significant linear correlation with the cumulative PAR interception of the canopy, enabling the estimation of the average RUE before heading with the slopes of the regression lines. Average RUE tended to increase with the increased level of nitrogen fertilization. RUE increased approaching maximum as the nitrogen nutrition index (NNI) calculated by the ratio of actual shoot N concentration to the critical N concentration for the maximum growth at any growth stage and the specific leaf nitrogen $(SLN;\;g/m^2\;leaf\;area)$ increased. This relationship between RUE (g/MJ of PAR) and N nutritive status was expressed well by the following exponential functions: $$RUE=3.13\{1-exp(-4.33NNNI+1.26)\}$$ $$RUE=3.17\{1-exp(-1.33SLN+0.04)\}$$ The above equations explained, respectively, about 80% and 75% of the average RUE variation due to varying nitrogen nutritive status of rice plants. However, these equations would have some limitations if incorporated as a component model to simulate the rice growth as they are based on relationships averaged over the entire growth period before heading.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.341-348
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• 2018

To investigate the effect of light sources on the growth and photosynthesis of the dwarf apple rootstock M.9 for the production of standard seedlings, the plants were cultivated in a controlled environment for 6 weeks. The sources of light are six treatments [Red (R), Blue (B), White (W), RBUV (R7B3 containing UV-A), RBW (R3B1W1), SMF (high pressure sodium + metal halide + fluorescent lamp) under $154{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Growth characteristics of apple seedlings varied depending on artificial light source at 3 weeks and 6 weeks. The plant height of apple seedling was high in the R, RBUV, RBW, and SMF light sources at 3 weeks, and in the R light at 6 weeks. There was no significant difference on stem diameter among the treatments at 3 weeks, but showed high in RBUV and RBW light at 6 weeks. Leaf number was the highest in RBUV light at 3 and 6 weeks. The chlorophyll content (SPAD value) was high in the B and RBUV light at 3 weeks, but it was not significant at 6 weeks. The growth rate to height of the R light (1.12mm/day) was the highest among the treatments, followed by RBUV, RBW, SMF, W and then B. Leaf area was the highest in RBUV and RBW lowest in B. Specific leaf area was high in W and fresh and dry weight were high in RBUV. The photosynthetic rate at 6 weeks was highest in the B and lowest in the R. Stomatal conductivity and transpiration rate were higher in the B and W compared to the other light sources. Therefore, we are considered that light sources for growth of dwarf apple rootstock M.9 seedlings are suitable the R, RBUV, and RBW light sources with a high mixing ratio of Red and Red +Blue.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.5-12
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• 2003

Seed germination rate and seedling growth were measured on 6 different species(Phytolacca americana, Eupatorium rugosum, Rumex acetocella, Echinochloa crusgalli, Cassia mimosoides var. nomame, Setaria viridis) treated with leaf extract of E. rugosum. Total phenolic compound and heavy metal were analyzed on leaf and soil with and without E. rugosum. The growth of P. americana seedlings were stimulated by 10% and 25% of E. rugosum water extract treatment. The content of total phenolic compounds in soil was lower than that of leaf extract, and 25% was confirmed as threshold concentration in natural systems because the total phenolic compounds were not significantly different between the control soils and the soil treated with 10%, and 25% extract. Total phenolic compound concentrations of the leaf extracts were highest (1.66 mg/l) with E. rugosum grown under the Quercus forest canopy and lowest (1.09 mg/l) for the plant grown in the mixed forest edge. Leaf extracts of plants selected in different sampling sites (Forest interior, Forest edge, under Pinus Canopy and Quercus Canopy) were significant, while soil extracts were not. Seed germination of R. acetocella and S. viridis were significantly inhibited at over 50% concentrations of E. rugosum, but C. mimosoides var. nomame was not affected at any concentration. The radicle and shoot growth of the native species group were reduced two times more than those of the exotic species group by the treatment of extracts. Especially, the seed germination percentage and dry weight of E. rugosum were greater than those of the control group by treatments with extracts of 10% and 25%. Analysis of aqueous extracts from E. rugosum by HPLC identified 6 phenolic compounds: caffeic acid (460.9 mg/l), benzoic acid (109.7 mg/l), protocatechuic acid (7.3 mg/l), ρ-hydroquinone (6.0 mg/l), cinnamic acid (2.7 mg/l) and hydroquinone (0.23 mg/l). The seed germination of P. americana was also inhibited dramatically by protocatechuic acid and cinnamic acid even though the content of caffeic acid (460.9 mg/l) was the highest among analyzed phenolic compounds. The heavy metal content of soil without A. altissima was higher than that of soil with E. rugosum. Particularly, Al, Fe and Mn was considerably high and most of the heavy metal were accumulated in leaves where a high level of total phenolic compounds was found.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.39-45
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• 1987

A water culture experiment was conducted to investigate the effect of As content in a culture solution on the water status and growth of rice plants. Rice (Oryza sativa L. Line. Iri 316) seeds were germinated in bentonite and cultivated there for 30 days. Rice seedlings were transplanted into 3.5l pots containing the culture solution on May 1, 1985 and allowed to grow without As treatment for one month. Afterwards, they were grown in a culture solution maintaining the final concentration of As, 0, 1, 5, 10 and 15mg/1 renewing in the solution dissolved sodium arsenate at intervals of 3 to 7 days. Plants were cultivated in the green house during the growing period and harvested 60 days after As treatment. The results obtained were as follows: Transpiration of rice plants was decreased with the increase of the As level in the culture solution. Stomatal diffusive resistance and leaf temperature increased with increase of As levels though the humidity and the air flow rate in leaf decreased. Air flow rate, transpiration and stomatal diffusive resistance showed a highly significant correlation with As contents in shoots and roots of rice plants: Espally The air flow rate and transpiration revealed a significantly higher correlation with As contents in the root than that in the shoot, but diffusive resistance showed adverse tendency. High levels of As in the culture solution depressed plant height, no. of tillers, leaf width and dry weight of plant remarkably. Typical symptoms of As toxicity were root discoloration, and necrosis of leaf tips and margins, and leaf rolling during the sunny daytime were also another symptoms.

• Journal of Environmental Science International
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• v.22 no.1
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• pp.17-23
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• 2013

In order to evaluate the effect of various organic soil conditioner ratios on the soil moisture content and growth of Cotoneaster horizontalis, a container type for wall-planting experiment was conducted in a greenhouse at Konkuk University under non-irrigation. The experimental planting grounds were prepared with different organic soil conditioner ratios ($A_1L_0$, $A_8L_1$, $A_4L_1$ $A_2L_1$ and $A_1L_1$), and a drought-tolerant ornamental variety of Cotoneaster horizontalis was planted. The change in soil moisture content, plant height, number of branches, number of dead leaves, number of leaves, number of shoots, length of node, length of leaf, width of leaf, root-collar caliper, chlorophyll content, and survival rate were investigated, from April to Jun 2010. The results of soil moisture content measurements were analyzed with weight units in the container type for wall-planting during the dry summer season. The soil moisture contents were significantly enhanced in the container type for wall-planting in increasing order as the amount of soil conditioner level was increased ($A_1L_1$ > $A_2L_1$ > $A_4L_1$ > $A_8L_1$ > $A_1L_0$). Compared to the control treatment application (amended soil with 100% + organic soil conditioner 0%), the highest plant growth was observed in the treatment of $A_1L_1$ application (amended soil with 50% + organic soil conditioner 50%). However, the differences between the organic soil conditioner ratio treatments of $A_1L_1$, $A_4L_1$, and $A_8L_1$ organic soil conditioner application were mostly not significant. The survival rate increased with the increasing application of organic soil conditioner, but in the control treatment application all the plants died. The experimental results from clearly demonstrated that the organic soil conditioner improved the survival rate more than the growth of Cotoneaster horizontalis. Therefore, Cotoneaster horizontalis is expected to be a highly valuable shrub for green wall systems, when considered for us in integration system or for increasing soil water contents in planting grounds.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.673-679
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• 2012

This study was conducted to examine the effect of artificial light source and photoperiod on the growth of leaf lettuce (Lactuca sativa L.) 'Seonhong Jeokchukmyeon' in a closed-type plant production system. Seedlings were grown under 3 light sources, fluorescent lamp (FL, Philips Co. Ltd., the Netherlands), WL #1 (Hepas Co. Ltd., Korea), and WL #2 (FC Poibe Co., Ltd., Korea), each with 3 photoperiods, 12/12, 18/6, and 24/0 (Light/Dark). An irradiance spectrum analysis showed that FL has various peaks in the 400-700 nm range, while WL #1 and WL #2 have only one monochromatic peak at 450 and 550 nm, respectively. The greatest plant height, fresh and dry weights were obtained in the 24/0 (Light/Dark) photoperiod. The 24/0 (Light/Dark) photoperiod treatment promoted vegetative growth of the leaf area. Length of the longest root, number of leaves, fresh weight, and total anthocyanin contents were greater in FL than in either WL #1 or #2. The greatest chlorophyll fluorescence (Fv/Fm) was found in the 12/12 (Light/Dark) photoperiod with FL treatment. The energy use efficiency of the LED increased by about 35-46% as compared to FL. Results suggest a possibility of LED being used as a substitute light source for fluorescent lamp for lettuce cultivation in a plant factory system.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.179-183
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• 1982

This experiment was carried out to clarify the optimal concentrations of growth regulators for callus induction and the condition of callus culture of leaf tissue taken from Stevia rebaudiana Bertoni. The content of stevioside, sweetening component, in leaf-derived callus of stevia was also investigated. It was shown that the optimal concentrations of benzyladenine (BA) and ${\alpha}-naphthalene$acetic acid (NAA) for callus induction were $10^{-6}M$ and $10^{-5}M$, respectively. Reculture of these calli in media (Linsmaier and Skoog) supplemented with BA $10^{-6}M$ and NAA $10^{-5}M$ resulted in profuse calli 15 to 20 days after incubation. When sweetening components produced by callus were extracted and identified by TLC, stevioside appeared to have Rf value 0.50 in TLC which was exactly same as standard stevioside. Stevioside content obtained by TLC-FID analyzer was 260mg per 100g on the basis of dry weight.

• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.112-119
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• 2004

Objective of this research was to evaluate the effects of nutrient solution strength and Arbuscular Mycorrhizal Fungi (AMF, Glomus sp.) on growth and flowering of potted miniature rose (Rosa hybrids L. cv 'Scarlet'). To achieve this, plants cultured with six different strength of Japanese Horticultural Experiment Station solution (0.125, 0.25, 0.5, 1.0, 2.0, and $4.0\;{\times}\;{full}$ strength) and inoculated with AMP at cutting and transplanting. Leachate EC increased as solution strength were elevated. The leachate EC were not different between non-inoculated plants and AMF treatment at cutting, but significantly decreased when plants were inoculated with AMF at transplanting. The elevated strength of nutrient solution resulted in decrease of leachate pH. When plants were inoculated AMF at transplanting, leachate pH was lower than those of non-inoculated plants and inoculated with AMF at cutting. At harvesting (93 days after transplanting), plant height, leaf width, number of branches and shoot fresh and dry weight of rose 'Scarlet' increased with elevated nutrient solution strength. AMF treatment at transplanting of potted rose 'Scarlet' showed the best results in growth such as chlorophyll content, number of flowers, and shortening the days required to flower. The content of N, P, K, and Mn in leaf tissue of potted rose increased by elevated nutrient solution strength and AMF treatment, while the tissue Na contents decreased by an AMF treatment.

• Korean Journal of Weed Science
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• v.2 no.2
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• pp.146-151
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• 1982

Herbicide mixtures, butachlor + naproanilide, CG113 + naproanilide and benthiocarb + naproanilide were tested in order to control Sagittaria pygmaea Miq., one of the most serious perennial weeds in paddy field of Honam area. 92% of tuber of Sagittaria pygmaea Miq. was distributed within 9cm from the soil surface and number of emerged Sagittaria pygmaea Miq. increased until 40 days after rice transplanting but decreased thereafter. Number and dry weight of survived Sagittaria pygmaea Miq. were much less in butachlor + naproanilide, CG 113 + naproanilide and benthiocarb + naproanilide treatments than perfluidone and it was controlled by up to 95% by mixture treatments. Number of rhizome of Sagittaria pygmaea Miq. was decreased by all herbicide treatments and especially mixture treatment significantly reduced rhizome formation compared to perfluidone and 2.4 -D treatments. CG113 + naproanilide treatment caused phytotoxicity that tip of leaf sticked to leaf sheath curvedly in Indica ${\times}$ Japonica rice, Iri 358, but it was recovered within 10 days after herbicide treatment.