• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.182-188
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• 1999

Production of extracellular polysaccharide by Monilinia fructigena in B-I medium containing cereals was higher than that in glucose medium. Productivities in B-I medium and glucose medium were 0.7g/l nd 0.2-03g/l respectively. The maximum content of polysaccharide occurred at the rising point from the lowest pH of culture. As the apparent viscosity of the polysaccharide solution increased, the flow Index (m) decreased, and the consistency Index (Kc) also increased. The polysaccharide solution was a typical pseudoplastic fluid. The mycelium was separated from the culture solution by $300\mu m$ mesh-filter and the polysaccharide was precipitated by adding 50% of ethanol (v/v). The amount of the polysaccharide removed from the filtrated solution was 0.45 g/l and the amount adhered to the mycelium was 0.25g/l. In experiments for investigating growth enhancement of rotifer (Brachionus plicatilis) by the polysaccharide, the dose of the polysaccharide was 1mg per 10,000 organisms of rotifer. Maximum specific growth rate of rotifer with feed consisting of sea Chlorella sp. and the polysaccharide was 1.095/day in the batch culture for 10 days. A semi-continuous culture was done for 30 days, the biomass of rotifer could be harvested twice. Maximum specific growth rate with sea Chlorella sp. and the polysaccharide was 0.734/day before the first harvest, and 1.685/day before the second harvest. Productivity was 38 $cells/ml\; \cdot\; day$ with sea Chlorella sp. and the polysaccharide.

• 한국작물학회지
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• 제50권1호
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• pp.1-4
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• 2005

This experiment was conducted to investigate the soil nitrogen credit of biological nitrogen fixation (BNF) and the nitrogen balance of soybean in soybean-barley cropping systems. Soybean cultivar, Shinpaldalkong2 and barley cultivar, Olbori, were used in soybean mono-cropping (SM), barley monocropping (BM), and barley­soybean double cropping system. The barley-soybean double cropping system was treated with two different levels of nitrogen fertilizers, 0 nitrogen fertilizer (BS-F0), and standard nitrogen fertilizer (BS-F1). Nitrogen and organic matter concentrations in soil of BS-F1 plot on October, 2001 were increased $4.8\%\;and\;5.9\%$, respectively, compared with those on October, 2000. The ranges of BNF rate in soybean were $69.1\~ 88.2\%$ in two years, and the rate was the highest in BS-F0 plot and the lowest in SM plot. The ranges of nitrogen harvest index (NHI) in all treatments were $83.9\~86.7\%$. The yield was 270 kg/10a in BS­F1 plot and 215 kg/10a in BS-F0 plot. However, the nitrogen balances were +0.6 kg/10a of gain of soil nitrogen in BS-F0 plot and -0.4 kg/10a of loss of soil nitrogen in BS-F1 plot. In comparisons of SM and BS-F1 plots, although the seed yields were similar in two plots, the loss of soil nitrogen was higher in SM than BS-F1 plot. Overall, our results suggest that barley-soybean double cropping system was more effective in respect to seed productivity and soil nitrogen conservation than soybean monocropping system, and the N credit to following crops by soybean cultivation was identified in soybean double cropping system.

• 한국자원식물학회지
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• 제11권1호
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• pp.80-85
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• 1998

The influence of elevated CO2 and temperature on growth parameters, biomass production and its partitioning of rice (Oryza sativa L.cv. Chukwangbyeo) were investigated in the three experiments (1991-1993). Rice plants were grown from transplanting to harvest at either ambient(350ppm) or elevated CO2 concentrations (690 or 650ppm) in combination with either four or seven temperature regimes ranging form ambient temperature (AT) to AT plus 3$^{\circ}C$.From transplanting to panicle initiation, crop growth rate (CGR) was enhanced by up to 27% with elevated CO2 , primarily due to an an increase in leaf area index. although net assimilatiion rate was also greater at elevated CO2. The effect of elevated CO2 varied with temperature. During the reproductive phase, CGR declined linearly with increased temperature, and was greater at elevated CO2 . Elevated CO2 increased final crop biomass and panicle weight 30% respectively at AT(27.6$^{\circ}C$ : 1991) . However, there was no significant effect of elevated CO2 on panicle weight at AT plus 3$^{\circ}C$, where severe spikelet sterility occurred. There was no significant effect of elevated CO2 on panicle weight at AT plus 3$^{\circ}C$, where severe spikelet sterility occurred. There was also no effect of CO2 on biomass pratitioning into vegetative and reproductive organs (harvest index)) at AT, although higher temperature could affect that by inducing spikelet sterility. These results suggest that elevated CO2 could enhance rice producivity througth promoted growth and biomass production , but its positive effects may be less at higher temperatures.

• 한국식품저장유통학회지
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• 제15권2호
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• pp.269-273
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• 2008

매실의 개체당 평균 수분 함량은 $88.34{\sim}90.04%$ 범위로서 수확시기에 따른 차이가 없었으며 조단백질과 조지방은 수확시기별로 수확시기가 늦어질수록 함량이 다소 감소하였으나 조섬유는 수확시기가 늦어짐에 따라 함량이 증가하였다. 또한 polyphenol 함량은 매실이 성숙함에 따라 점차 증가하는 경향을 보였다. methanol, water, hexane, ethylacetate 및 ether 추출물의 항균활성 검색 결과 methanol에서 가장 크게 나타났으며 수확시기가 늦어질수록 항균활성은 증가하는 경향을 나타내었다. 항균활성을 가진 메탄을 추출물의 활성은 $100^{\circ}C$에서 30분 가열한 조건에서도 안정함을 확인하였고, pH 변화에 따른 안정성은 큰 차이를 보이지 않았다. 용매에 따른 전자공여능은 methanol > ethylacetate > water > ether > hexane 순으로 높게 나타났으며 수확시기에 따른 차이는 크지 않았다.

• 한국식품영양학회지
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• 제31권2호
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• pp.220-228
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• 2018

This study investigated the chemical composition of burdock (Arctium lappa L.) leaves essential oil, and the quantitative changes of the major terpene compounds according to the specific harvesting season. The essential oils obtained by the hydrodistillation extraction (HDE) method from the aerial parts of the burdock leaves were analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). The essential oil composition of this plant was characterized by the higher content of phytol and 6,10,14-trimethyl-2-pentadecanone. Seventy seven (98.28%) volatile flavor compounds were identified in the essential oil from the burdock leaves harvested during the spring season of 2012, and phytol (33.47%) and 6,10,14-trimethyl-2-pentadecanone (32.47%) were the most abundant compounds. Eighty eight (99.08%) compounds were identified in the essential oil from the leaves harvested during the autumn season of 2012, and in this case, phytol (37.35%) and 6,10,14-trimethyl-2-pentadecanone (34.67%) were also the most abundant compounds. These two volatile components were confirmed as the major oil components of the burdock leaves during the time of any harvest. The ratio between the two components contained in the burdock essential oils did not differ significantly by harvesting season. But overall, the essential oil harvested during the spring season contained 65.94% of the two major components, while for the essential oil harvested during the autumn season, the total amount of these two major components was 72.02%. While the main ingredients of the essential oils were found to be unchanged from one harvest time to the next, it was found to differ in content. For the burdock leaves, the quality index of the volatile constituents according to the harvest time would be more useful for utilizing the total quantity other than the proportion between phytol and 6,10,4-trimethyl-2-pentadecone.

• 한국식품영양학회지
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• 제28권4호
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• pp.533-543
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• 2015

This study investigated the chemical composition of Artemisia princeps var. orientalis (Pampan) Hara (ssuk in Korea) essential oil and the quantitative changes of major terpene compounds according to the time of harvest. The essential oils obtained by hydrodistillation extraction from the aerial parts of ssuk were analyzed by GC and GC-MS. The essential oil composition of ssuk was characterized by higher contents of mono- and sesqui- terpene compounds. Ninety-nine volatile flavor compounds were identified in the essential oil from ssuk harvested in 2010, with camphor (11.9%), ${\beta}-caryophyllene$ (9.11%), dehydrocarveol (8.51%), and borneol (7.72%) being the most abundant compounds. Eighty-three compounds were identified in the essential oil from the plant harvested in 2011, with borneol (12.36%), caryophyllene oxide (12.29%), ${\beta}-caryophyllene$ (10.24%), camphor (9.13%), and thujone (8.4%) being the most abundant compounds. Eighty-four compounds were identified in the essential oil from the plant harvested in 2012, with ${\beta}-caryophyllene$ (20.25%), caryophyllene oxide (14.63%), and thujone (11.55%) being the major compounds. Eighty-nine compounds were identified in the essential oil from the plant harvested in 2013, with thujone (23.11%), alloaromadendrene oxide (12.3%), and ${\beta}-caryophyllene$ (11.48%) being the most abundant compounds. Thujone and aromadendrene oxide contents increased significantly from 2010 to 2013, while camphor and dehydrocarveol contents decreased significantly during those 4 years. The quantitative changes in these 4 compounds according to the time of harvest can served as a quality index for ssuk essential oil. The ecological responses to recent climate changes may be reflected in the chemical components of natural plant essential oils.

• 한국초지조사료학회지
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• 제18권4호
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• pp.291-302
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• 1998

식물생장 조절제 Uniconazole-P의 처리가 초지조건에서 목초의 생육억제와 종자생산에 미치는 영향을 검토하였다. 초종은 화본과 목초 2초종(orchardgrass와 timothy)과 두과목초 2초종(red clover와 alfalfa)을 공시하였고, Uniconazole-P의 처리농도는 대조구, 20ppm구, 40ppm구의 3처리로 하여, 화본과 목초는 유수분화기에, 두과목초는 개화시기(開花始期)에서 엽면산포하였다. 본 실험에서 얻어진 결과를 요약하면 다음과 같다. 1. Uniconazole-P의 처리효과는 처리농도, 초종 및 생육단계에 따라서 차이가 인정되었다. 2. Uniconazole-P의 처리는 출수초기의 화본과 목초에서 초장과 간장이 단축되었고, 수중과 엽록소 함량을 증가시켰다. 3. Uniconazole-P의 처리는 종자 결실기의 orchardgrass에서 수수, 1경중, 수중, 1수중 및 종자중을 증가시켰고, timothy에서는 초장의 단축과 수수, 1수중, 수중, 종자중 및 수확지수를 증가시켰다. 4. Uniconazole-P의 처리는 개화초기의 red clover와 alfalfa 2초종 모두 초장과 총절간장을 단축시켰지만, 총분지장과 엽록소 함량을 증가시켰다. 특히 red clover에서는 화수와 화중의 증가가 현저하였다. 5. Uniconazole-P의 처리는 종자 결실기의 red clover에서 초장을 단축시켰고, 화중과 종자중을 증가시켰으며, alfalfa에서는 초장을 단축시키고 화중, 종자중 및 수확지수를 증가시켰다. 6. Uniconazole-P의 처리에 의한 화본과 목초의 종자 생산과정은 1) 출수초기에서 초장과 간장의 단축, 2) 출수초기와 종자 결실기에서 수수와 l수중의 증가, 3) 종자 결실기에서 단위면적당 수중과 종자중의 증가 및 수확지수의 증가로 설명할 수 있다. 7. Uniconazole-P의 처리에 의한 두과목초의 종자 생산과정은 1) 개화초기에서 초장과 총절간장의 단축과 분지수와 총분지장의 증가, 2) 개화초기와 종자 결실기에서 화수와 화중의 증가, 3) 종자 결실 기에서 종자중과 수확지수의 증가로 설명할 수 있다.

• 생물환경조절학회지
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• 제21권2호
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• pp.95-101
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• 2012

본 연구는 해발 750m 이상의 고랭지에서 재배된 양배추의 정식시기 및 수확 시 기상환경이 품질에 미치는 영향과 수확 후 저장 중 품질변화를 조사하기 위해서 수행하였다. 수확 된 양배추의 품종 별 구중은 정식시기 및 수확시기가 늦으면 구중이 감소하는 양상을 보이며 상품성이 낮았다. 반면 8월 23일(3차)에 수확된 양배추 품종은 정식시기 및 수확시기가 8월 3일(1차)과 8월 13일(2차)에 비해 늦었음에도 불구하고 수확기의 기상환경이 좋아 경도 및 가용성 고형물의 함량이 높았다. 가용성 고형물의 함량은 수확 전후의 기상환경에 영향을 받아 수확 전 3일 이상 강우가 없을 때 수확하는 것이 높게 유지하였고, 경도는 늦은 정식시기가 경도를 낮추는 것으로 나타났다. 양배추의 색도는 수확기에 따른 변화는 일정한 경향이 없었으며, 품종간에도 유의적인 차이는 보이지 않았다. 공시품종 중 수확 시 품질은 'Speed king'과 'Minix 40' 품종이 가장 우수하였다. 양배추 저장은 8월 3일(1차), 8월 23일(3차), 그리고 9월 10일(4차)에 수확된 양배추를 상온($25^{\circ}C$, 60% RH)과 저온($3^{\circ}C$, 85% RH)에 각각 저장하여, 수확시기와 수확기의 기상환경이 상온 및 저온저장에 미치는 영향을 확인하였다. 양배추의 생리장해는 수침, 시들음, 냉해가 저장기간 4일경부터 발생하여 상품성을 상실하였다. 양배추 6개 품종의 저장기간은 수확 시 기상환경에 따라 상온저장의 경우 3~5일, 저온저장의 경우 9~10일 정도 가능하였다. 특히 8월 3일(1차)에 수확한 양배추는 수확일 전후의 열악한 기상환경으로 실온 및 저온 저장기간이 가장 짧아 실온 2일 그리고 저온은 4일의 저장기간을 보였다.

• 한국환경복원기술학회지
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• 제8권2호
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• pp.33-40
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• 2005

The objective of this research was to find an indirect method to estimate spectral reflectance and NDVI(Normalized Difference Vegetation Index) efficiently, using the spectroradiometer and NOAA AVHRR satellite data. For collecting RS base data, used spectro-radiometer that measures reflection characteristics between 300~1,100nm was used and measured the reflection of vegetation from paddy rice during the growing season at Chungbuk national university's farm in 2002. The feasibility of detecting the temporal variation in the spectral reflectance and NDVI in paddy rice were conducted on eight growth stages. AVHRR data were collected in eight different months over a one year period in 2002. The results were compared with those obtained by analyzing NDVI characteristics. The spectral reflectance and NDVI of paddy rice have a great effect on the growth condition. Considerably, NDVI was increased by developing muscle fiber tissue at the near infrared wavelength until the Booting stage. Then the NDVI increased until the Maturity stage and then decreased until harvest. The highest month was at July and the lower month was at March. The difference NDVI analysis using March and another months data was conducted, the results were provided information on the growth condition of crops.

• 한국작물학회지
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• 제49권5호
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• pp.394-406
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• 2004

A split-plot designed experiment including four rice varieties and 10 nitrogen levels was conducted in 2003 at the Experimental Farm of Seoul National University, Suwon, Korea. Before heading, hyperspectral canopy reflectance (300-1100nm with 1.55nm step) and nine crop variables such as shoot fresh weight (SFW), leaf area index, leaf dry weight, shoot dry weight, leaf N concentration, shoot N concentration, leaf N density, shoot N density and N nutrition index were measured at 54 and 72 days after transplanting. Grain yield, total number of spikelets, number of filled spikelets and 1000-grain weight were measured at harvest. 14,635 narrow-band NDVIs as combinations of reflectances at wavelength ${\lambda}l\;and\;{\lambda}2$ were correlated to the nine crop variables. One NDVI with the highest correlation coefficient with a given crop variable was selected as the NDVI of the best fit for this crop variable. As expected, models to predict crop variables before heading using the NDVI of the best fit had higher $r^2$ (>10\%)$ than those using common broad- band NDVI red or NDVI green. The models with the narrow-band NDVI of the best fit overcame broad- band NDVI saturation at high LAI values as frequently reported. Models using NDVIs of the best fit at booting showed higher predictive capacity for yield and yield component than models using crop variables.