• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.53-59
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• 1990

Root zone environments in hydroponics are very important factors in crop growth, development and quality. In Korea, improvement of root zone temperature is required because of the continental climate. Therefore, this investigation was carried out to clarify the difference of root zone environments in different hydroponic systems under different climates. Tomato plants were grown in nutrient solutions at Seoul City University and Allen Cooper's. Hydroponic systems in this experiment were aeroponics, nutrient film technique(NFT), rockwool culture, sand culture and smoked rice hull culture(SRH). The decrease in temperature rapidly occured in sand culture while slowly in rockwool culture in low air temperature periods. The internal temperature of substrates of hydroponic bed were slightly changed in rockwool culture under high air temperature periods, while the duration of high temperature was longest in NFT. Electrical conductivity and pH of nutrient solution showed great changes in rockwool and aeroponics. Along the bed, the content of dissolved oxygen in nutrient solution had a tendency to decrease in NFT and DFT(Deep flow technique), while didn`t a change with aeroponics. Root activity measured by triphenyl tetrazolium chloride (TTC) was highest with aeroponics, followed by rockwool culture and NFT.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.159-166
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• 1995

This experiment was aimed to investigate the growth and yield responses of hydroponically grown cucumber as affected by cultural containers and substrates using perlite and mixtures with perlite. Containers used in this experiment were bed and box made of styrofoam, PE film and Wagner pot and substrates used were perlite, peatmoss, rice hull and carbonized rice hull. The results obtained were as follows : Based on the growth and yield responses determined from the leaf area and total fruit weight, bed and box made of styrofoam was considered the best containers among tested for cucumber hydroponics. Recommendable substrates for hydroponically grown cucumber using perlite were evaluated in the order of perlite, perlite with rice hull and perlite with carbonized rice hull in styrofoam bed and box. Increase in marketable yield and decrease in abnormal fruits was observed in the mixed substrates with rice hull or carbonized rice hull when compared to perlite single media.

• Journal of the Korean Society of Food Culture
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• v.5 no.4
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• pp.481-485
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• 1990

This study is designed to forecast the characteristics in food consumption patterns under per capita GNP growth. Ordinary least square(OLS)method was employed as analyzing technique. Equation was $Y=a_0+a_1X$, in which X was per capita GNP and Y were Engel coefficient, food supply, energy supply, nutrient intake and ratio of self-supply of food. The result obtained indicates that the intake of nutrient such as protein and fat will be increased, and wheat, corn and legume are expected to be imported wholly due to lower ratio of self-supply, and rice will be over-supplied continually. Therefore, the relevant policy of government must be established in the field of supply and demand of food, and the research of sound national health should be done.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.1
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• pp.32-37
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• 2001

Fabrea salina is an euryhaline ciliate living at salt pond. Its size is small as ca. $150{\mu}m$, and its reproductive rate is high, so that this ciliate has been expected to be a new food organism which will be able to replace rotifer, Brachionus plicatilis. However, the dietary value of F. salina on fish larvae has not yet been verified thoroughly. This research was carried out to understand the mass culture technique and dietary value of this ciliate. In this study, six kinds of phytoplankton and three kinds of grain were tested on growth of the ciliate and optimum temperature, salinity and density of food were also examined for its mass culture. Regarding food for the ciliate, Heterosigma sp. and rice showed the highest growth among the phytoplankton and the grain, respectively. In this study, 229 ciliates per mL was cultured with Heterosigma sp., and 220 ciliates per mL with rice. The optimum temperature for F. salina was $33^{\circ}C$, and salinity ranging from 35 to 95 ppt had no significant difference on its growth. The optimum food density and amount for the ciliate were $5\times10^6$ cells/mL in Heterosigma sp. and 2.8 g/L in rice, respectively. With respect to dietary value of F. salina, six-day-old larvae of ayu, Plecoglossus altivelis, fed on the ciliate showed the high mortality over $96\%$ within 3 days, and it was significantly higher than those fed on rotifer. Even though the mass culture of F. salina has been achieved in the study, this ciliate seems to be inadequate as a food organism for fish larvae.

• Journal of Mushroom
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• v.4 no.3
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• pp.101-105
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• 2006

This was performed to improve the working conditions of oyster mushroom cultivation on bed using rice straw of which binding and cutting procedure need a lot of time. There was a little difference in physiochemical components between rice straw and cotton waste C/N ration of cotten waste was, however, similar to rice straw as 84-85. If is feasible to use as substrate material. The average yield of a net was 1450g in six frustration harvest, when the size of an onion net was $35{\times}30cm$, mixture ratio of rice straw to cotton waste was 40:60(V/V). Cultivation method using an onion net saved 3 days for preparation, 4 hours for inoculation compared to normal bed cultivation. This method was analysed to give 5% economical benefit.

• Journal of Life Science
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• v.31 no.4
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• pp.385-388
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• 2021

Anther cultivation for crop breeding is a method of rapid production of homozygosities by greatly reducing the time required for at least six generations to develop new varieties using conventional breeding methods. This technique of producing anther culture provides an opportunity to obtain more green plants from a methodological point of view, and the techniques that save time and effort in anther culture are also important because they increase the efficiency of culture. This study compared the callus induction rate and green plant regeneration rate of a one-step and a two-step culture that differ in their culture media and culture methods. One-step culture allows callus induction and plant regeneration in one medium, whereas two-step culture requires induction and plant regeneration in two different media. In this study, we compared the callus induction and plant regeneration rates of rice anthers as one-step and two-step cultures. The callus formation rate was 13.0% for one-step cultures and 8.6% for two-step cultures, so the rate was 4.4% higher for one-step cultures than for two-step cultures. The plant regeneration rate was 1.0% in one-step cultures and 3.0% in two-step cultures, so the regeneration rate was three times higher for the two-step cultures than for one-step cultures. This suggests that the two-step cultures are more efficient than the one-step cultures for haploid production.

• Journal of Mushroom
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• v.5 no.2
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• pp.81-85
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• 2007

This study was carried out to investigate the conditions of liquid culture and fruiting body formation of Cordyceps militaris using grain mediacontained the brown rice and black purple rice. Liquid mycelial growth and density of Cordyceps militaris were the highest in the medium of malt extract 0.7% and pH 5.0~5.5. The optimal condition of formation the fruiting bodies were shown to be temperature of $17^{\circ}C$, light intensity of 600 lux, $C0_2$ of 500ppm and humidity intensity of 95% produced highest amount of fruit bodies.

• Journal of the Korean Society of Food Culture
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• v.34 no.4
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• pp.463-473
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• 2019

The aim of this study is to identify the value structure of active seniors for noodles. Noodles are the secondly most preferred and familiar food in Korea, followed by rice. And noodles also have a variety of tastes/flavors and even a variety of ceremonial characteristics. The necessity of offering proper food to seniors has recently increasing because Korea becoming an aged society. This study conducted 1:1 in-depth interviews with 30 active senior participants using the soft laddering technique, which is based on the means-end chain theory. The Implication Matrix and HVM were derived from performing content analysis. The active seniors mainly consider the 'taste', expecting to obtain the 'satisfying taste', and pursuing the 'family affair', 'pleasure', and 'self-satisfaction'. The results of this study indicated that the taste is the most important attribute and the active seniors consider their family as well as the pleasure and satisfaction of their own. Male seniors mainly pursue the 'pleasure' and 'self-satisfaction' by satisfying their taste through considering 'taste' and 'familiarity'. But female seniors mainly pursue the 'family affair' by 'satisfying taste' through considering 'taste'. These results can be used as a basic data for developing noodle products for the elderly. This study will also contribute to the development of special care food and product concepts for the silver generation.

• Journal of the Korean Society of Food Culture
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• v.23 no.4
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• pp.438-447
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• 2008

"Gyuhapchongseo" was published in 1809, and introduced the cooking method of the noble class in the late Joseon dynasty. The characteristics of the side dishes in "Gyuhapchongseo" are as follows. Firstly, red pepper was used as whole red pepper, shredded red pepper, powdered red pepper, or Korean hot pepper paste. Secondly, salt-fermented fish was used in some forms of Kimchi, including Sukbakgi, Dong A Sukbakgi, and Gyochimhae. Thirdly, to retain the juiciness of meat during roasting, meat was spread cold water on the surface, dipped into the washing water of rice or wrapped with wet paper. Fourth, to improve the visual effect of a dish, cooked foods were displayed with various color schemes, panfried foods with two tones (egg white and yellow) of color on each side and the use of radish pigmented with deep red color. On examination of the characteristics of food in "Gyuhapchongseo", I would suggest applicable practices for the present cuisine. The use of gravy produced from the boiling down of fish flesh could raise the nutritive value of Kimchi. In "Gyuhapchongseo", Yak po (semi-dried minced beef) is noted as being good for elderly people with bad teeth. A steamed dish with dog meat in Dong A in "Gyuhapchongseo" is made by hollowing out Dong A and putting a dog in it to cook the dog meat to well done in a fire made with the hulls of rice. This technique could be used to present cuisine for steamed and roasted dishes using food ingredients such as pumpkin, sweet pumpkin, and overripe cucumber.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.288-298
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• 1992

Since the major important factors limiting plant growth and crop productivity are environmental stresses, of which low temperature is the most serious. It has been well known that many physiological processes are alterant in response to the environmental stress. With regard to the relationship between plant hormones and the regulation of chilling tolerance in rice seedlings, the major physiological roles of plant hormones: abscisic acid, ethylene and polyamines are evaluated and discussed in this paper. Rice seedlings were grown in culture solution to examine the effect of such plant hormones on physiological characters related to chilling tolerance and also to compare the different responses among tested cultivars. Intact seedlings about 14 day-old were chilled at conditions of 5$^{\circ}C$ and 80% relative humidity for various period. Cis-(＋)-ABA content was measured by the indirect ELISA technique. Polyamine content and ethylene production in leaves were determined by means of HPLC and GC respectively. Chilling damage of seedlings was evaluated by electrolyte leakage, TTC viability assay or servival test. Our experiment results described here demonstrated the physiological functions of ABA, ethylene, and polyamines related to the regulation of chilling tolerance in rice seedlings. Levels of cis-(＋)-ABA in leaves or xylem sap of rice seedlings increased rapidly in response to 5$^{\circ}C$ treatment. The tolerant cultivars had significant higher level of endogenous ABA than the sensitive ones. The ($\pm$)-ABA pretreatment for 48 h increased the chilling tolerance of the sensitive indica cultivar. One possible function of abscisic acid is the adjustment of plants to avoid chilling-induced water stress. Accumulation of proline and other compatible solutes is assumed to be another factor in the prevention of chilling injuies by abscisic acid. In addition, the expression of ABA-responsive gene is reported in some plants and may be involving in the acclimation to low temperature. Ethylene and its immediate precusor, 1-amincyclopropane-1-carboxylic acid(ACC) increased significantly after 5$^{\circ}C$ treatment. The activity of ACC synthase which converts S-adenosylmethionine (SAM) to ACC enhanced earlier than the increase of ethylene and ACC. Low temperature increased ACC synthase activity, whereas prolonged chilling treatment damaged the conversion of ACC to ethylene. It was shown that application of Ethphon was beneficial to recovering from chilling injury in rice seedlings. However, the physiological functions of chilling-induced ethylene are still unclear. Polyamines are thought to be a potential plant hormone and may be involving in the regulation of chilling response. Results indicated that chilling treatment induced a remarkable increase of polyamines, especially putrescine content in rice seedlings. The relative higher putrescine content was found in chilling-tolerant cultivar and the maximal level of enhanced putrescine in shoot of chilling cultivar(TNG. 67) was about 8 folds of controls at two days after chilling. The accumulation of polyamines may protect membrane structure or buffer ionic imbalance from chilling damage. Stress physiology is a rapidly expanding field. Plant growth regulators that improve tolerance to low temperature may affect stress protein production. The molecular or gene approaches will help us to elucidate the functions of plant hormones related to the regulation of chilling tolerance in plants in the near future.