• 제목/요약/키워드: STEM research

검색결과 2,903건 처리시간 0.056초

Effects of Water Conditions and Rhizobium Inoculation on the Growth of Wisteria floribunda Seedlings in Slope Soils (절개지 토양에서 수분조건과 근류균 접종이 등나무 유묘생장에 미치는 영향)

  • Park, Chong-Min
    • Korean Journal of Environment and Ecology
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    • 제20권4호
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    • pp.425-435
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    • 2006
  • The objectives of this research were to investigate the drought resistance as well as the growth of Wisteria floribunda seedlings with the soil water conditions. The seedlings for the research were grown in pots with strict water content control on a frame located outdoors. During the experiments, the soil water contents were adjusted to 5, 10, 20, 30, 40, 50, 60, and 70%. In addition, the effects of Rhizobium inoculation on the growth of seedlings were investigated. The experimental results are summarized as follows: 1. The seedlings in the pots with 5% soil water content withered to death due to the water stress. Withering or any distinct growth was not observed from the seedlings in the 10% soil water content. It can be inferred from these results that about 5% of soil water content is the wilting point of W. floribunda seedlings and about 10% is the critical soil water content of its growth in this experiment soils. Therefore, it seems that W. floribunda possesses a good drought resistance. 2. From the analyses of the main growth parameters such as stem elongation, diameter growth, leaf area growth and total dry weight, it was found that the seedling growth can be improved with increasing soil water contents. The relation between each growth parameter(Y) and the soil water contents(W) was well described by a quadratic equation, $Y=a+bW+cW^2$. 3. In soil water contents higher than 20%, the seedling growth(Y) was remarkable along with-its extended growing period, and related to the growing period(D) by a quadratic equation, $Y=a+bD+cD^2$. 4. The artificial inoculation of Rhizobiun promoted the growth of Wisteria floribunda seedlings. 5. Rhizobium was found to be more readily inoculated and to form more root nodules compared to seedlings grown in higher soil water contents.

Effect of Pinching Times on Growth and Yield of Okra (Abelmoschus esculentus L.) in Rain Shielding Vinyl Houses (비가림 재배 시 오크라의 적심처리 시기가 생육 및 수량에 미치는 영향)

  • Kim, Young Suk;Yoo, Mi Bok;Go, Hung Six;Kim, Tae Soo;Kim, Chun Hwan;Seong, Ki Cheol
    • Journal of Bio-Environment Control
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    • 제24권2호
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    • pp.119-122
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    • 2015
  • The experiment was carried out to examine the effect of pinching time on growth and marketable yield of okra in rain shielding vinyl houses. Okra (Abelmoschus esculentus L., 'Green sod') seedling was transplanted in May, 2013. Pinching times of okra were in each 30th, 45th, 60th day after transplanting of okra. Shoot branch and top fresh weight were significantly different between each pinching times. Top fresh weight were highest at 60th day pinching time after transplanting investigated, and were lowest at 30th day pinching time after transplanting. There was no significant difference in plant height and stem length among pinching times. According to pinching times, marketable yield and number of okra fruits were varied. Marketable yields were highest at 60th day after transplanting, whereas were lowest at 30th day after transplanting. Mineral concentrations of okra fruits were not significantly different among pinching times. Therefore pinching times 60th day after transplanting was effective to increase yield of okra fruit in rain shielding vinyl houses.

Species Identification and Developmental Biology of a Red Bean Pest in Ostrinia sp. (Lepidoptera: Crambidae) (Ostrinia속(나비목: 포충나방과) 팥 해충의 종 동정과 발육 특성)

  • Jung, Jin Kyo;Seo, Bo Yoon;Park, Doo-Sang;Oh, Hyun-Woo;Lee, Gwan-Seok;Park, Hae-Chul;Cho, Jum Rae
    • Korean journal of applied entomology
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    • 제51권4호
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    • pp.469-477
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    • 2012
  • Ostrinia larvae feed the pods and stem of red bean and seriously damage the bean production from farmers. In this study we investigated biological and developmental characteristics including field collection, host feeding preference, artificial rearing diet, morphological and molecular taxonomical identification, and pheromone analysis for an Ostrinia sp. in Korea. The male adults have massive tibia in the middle legs and 3-lobed uncus in the genitalia. The partial nucleotide sequences of mitochondrial cytochrome oxidase I (COI) and II (COII) were not corresponded to those DNA sequences from other Ostrinia species reported previously in Japan and China. Host plants for this species are also different from the previous species reported. In the gas chromatography (GC) analyses, (Z)-9-tetradecenyl acetate was not detected from the pheromone gland of our species while the component as a sex pheromone was found in O. zaguliaevi and O. zealis, With taken results, we conclude this Ostrinia species in Korea is Ostrinia scapulalis or closely related species. When larvae collected in a fall were incubated in the outdoor condition, they emerged to adult between June and July in the next year. The result indicates that the winter diapause could be started in late larval stage. In addition, we developed a semi-synthetic artificial diet adopted for mass rearing of the O. scapulalis in laboratory.

Studies on the Morphological and Physiological Characteristics of Pleurotus cystidiosus O.K.Miller, the Abalone Mushroom (전복느타리버섯(Pleurotus cystidiosus O.K.Miller)의 형태적 및 생리적 특성에 관한 연구)

  • Jang, Kab-Yeul;Jhune, Chang-Sung;Shin, Chul-Woo;Park, Jung-Sik;Cheong, Jong-Chun;Choi, Sun-Gyu;Sung, Jae-Mo
    • The Korean Journal of Mycology
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    • 제31권3호
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    • pp.141-147
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    • 2003
  • The pileus of Pleurotus cystidiosus was attached at the side and was spatular-shape. It grew to the size of $7.6{\sim}9.8\;cm$ with dark brown color. The length of stem was $1.4{\sim}2.9\;cm$. The individual weight of fruiting-body was 25.4 g in average. This study was conducted to Investigate the physiological characteristics and to develop the artificial cultivation technique of P. cystidiosus. To find out the optimum condition of mycelial growth of P. cystidiosus, physiological conditions such as media, temperature, pH carbon sources and nitrogen sources were investigated. Various cultural media were used for the cultivation of P. cystidiosus and compost dextrose agar was favorable for mycelial growth. The optimal growing temperature and pH were in range of 25 to $30^{\circ}C$, pH $7{\sim}9$, respectively. When different carbon sources were compared, glucose was found to be best. However nitrogen sources were different with each strains. When different C/N ratio were compared, 20:1 of C/N ratio was found to be best.

Physicochemical Characteristics of Agastache rugosa O. Kuntze Extracts by Extraction Conditions (추출조건에 따른 배초향 추출물들의 이화학적 특성)

  • Lee, Boo-Yong;Hwang, Jin-Bong
    • Korean Journal of Food Science and Technology
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    • 제32권1호
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    • pp.1-8
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    • 2000
  • Fifty-seven extracts from flower, leaf and stem of Agastache rugosa O. Kuntze were prepared by varing extraction conditions: solvents (hot water, ethanol and NaCl solution); temp.$(60,\;80\;and\;100^{\circ}C)$ and solvent ratios (10 to 35 times per material). Lipid content of leaf was 9.54% and protein content of the flower where the essential amino acids were most abundant among all parts was 16.8%. Among six minerals (Na. Ca, Fe, P, K and Mg) detected from all parts of the plant, the content of K was the highest. Extraction yield rated higher in odor of water, ethanol and NaCl solution, respectively and the extractions reached eqilibrium in about 15 to 20 min, regardless of extraction conditions. pH values of all extracted solvents maintained neutral upon extraction and a few free sugars in forms of glucose and fructose were detected from ethanol extracts. Colors and organoleptic characteristics of the extracts which determine the properties of final products varied with extraction conditions.

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Analysis of the Various Constituents and Comparison of Biological Activities of Different Parts of Allium victorialis var. platyphyllum (산마늘의 부위별 성분분석 및 생리활성 평가)

  • Kim, Jin-Young;Cho, Jeong-Yong;Na, Hwan-Sik;Choi, Gyeong-Cheol;Park, Jong-Soo;Lee, Ji-Heon;Jeong, Seon-Ho;Moon, Jae-Hak
    • Korean Journal of Food Science and Technology
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    • 제44권1호
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    • pp.100-105
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    • 2012
  • Analysis of the various constituents and determination of biological activities in the different parts (root, stem, and leaf) of Allium victorialis var. platyphyllum were carried out. Potassium and calcium were detected in higher contents (mg/100 g fresh wt.) than other minerals. The total phenolic content (mg tannic acid eq./100 g dry wt.) decreased in the order of leaves ($792.7{\pm}16.6$) > stems ($160.3{\pm}6.8$) > roots ($101.5{\pm}2.7$), and the total flavonoid content (mg quercetin eq./100 g dry wt.) was as follows: leaves ($497.9{\pm}11.1$), roots ($35.7{\pm}0.4$), stems ($18.5{\pm}1.4$). DPPH radical-scavenging activity and inhibition activity against the formation of cholesteryl ester hydroperoxide in rat blood plasma was higher in the leaves than in roots and stems. Extracts of A. victorialis separated by parts displayed antimicrobial activity against Clostridium perfringens, Staphylococcus aureus, Listeria monocytogenes, Vibrio vulnificus, Vibrio parahaemolyticus, of which the strongest activity was against C. perfringens.

The Isolation and Characterization of the Antagonistic Microorganisms, Serratia marcescens-YJK1, for Major Pathogens on Paprika (파프리카에 발생하는 주요 병원균에 대한 길항미생물, Serratia marcescens-YJK1, 분리와 특성)

  • Yang, Soo-Jeong;Kim, Hyung-Moo;Ju, Ho-Jong
    • Korean Journal of Organic Agriculture
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    • 제22권4호
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    • pp.855-868
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    • 2014
  • Synthetic agro-chemicals have been widely used to control diseases on paprika but these days negative attention has been increasing to use of them because of several adverse effects. This research was conducted to isolate and to characterize the antagonistic microorganism to control major paprika diseases, gray mold rot, fruit and stem rot, phytophthora blight, sclerotium rot, and wilt disease. Analysis of the fatty acid and analysis of the 16S rDNA gene sequence revealed that YKJ1 isolated in this research belongs to a group of Serratia marcescens. Specially, 16S rDNA gene sequence of YKJ1 showed 99% of sequence similarity with S. marcescens. Observation through the optical microscope revealed that YKJ1 suppressed the spore germination and the hyphal growth of pathogens. YKJ1 treatment on pathogens induced marked morphological changes like hyphal swelling and degradation of cell wall. In the case of phytophthora blight, the zoosporangium formation was restrained. S. marcescens found in this study call as S. marcescens-YKJ1 and it may be valuable as one of biological control agents against major diseases of paprika in the future even though it is require to be tested with more study on field test.

Effects of Seeding Rate on Growth Characters, Yield Potential and Feeding Value in Jeiu Italian Millet (제주조의 파종량 차이에 따른 생육반응, 수량성 및 사료가치 변화)

  • Cho, Nam-Ki;Ko, Dong-Hwan
    • Journal of The Korean Society of Grassland and Forage Science
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    • 제23권4호
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    • pp.271-276
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    • 2003
  • A Jeju local variety of Italian millet (Setaria italica Beauvois) was grown at five seeding rates (6, 9, 12, 15 and 15 kg/ha) from May 1 to August 25, 2003 at Jeju to determine influence of seeding rate on agronomic characters, forage yield and quality. Days to flowering increased from 89 to 96 days as seeding rate increased from 6 to 18 kg/ha. The plant height increased from 128 to 148cm as seeding rate was increased from 6 to 12 kg/ha and then decreased to 131cm at a rate of 18 kg/ha. With increasing seeding rate, stem diameter, number of leaves, number of nodes, leaf width and weight per plant decreased but leaf length had the same trend with plant height. As seeding rate increased from 6 to 12 kg/ha, fresh furage, dry matter, crude protein, and total digestible nutrients (TDN) yield increased from 35.93 to 54.83 MT/ha, 10.49 to 17.43 MT/ha, 0.94 to 1.79 MT/ha and 5.33 to 9.27 MT/ha, respectively, and then decreased with further increased seeding rates. Crude protein, either extract, nitrogen free extract, and TDN content increased 9.0 to 12.01%, 1.3 to 1.8%, 45.6 to 47.8% and 50.8 to 55.0%, respectively, but crude fiber content decreased 35.2 to 30.0% and crude ash declined 5.8 to 8.4% as seeding rate increased from f to 18 kg/ha. The optimum seeding rate to obtain the highest forage yield was estimated to be 12 kg/ha.

Effect of Seeding Dates on Ecological Response, Yield Potential and Feed Value in Jeju Italian Millet (제주조의 파종기에 따른 생태반응, 수량성 및 사료가치 변화)

  • Cho, Nam-Ki;Ko, Dong-Hwan
    • Journal of The Korean Society of Grassland and Forage Science
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    • 제23권4호
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    • pp.265-270
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    • 2003
  • This study was conducted to determine the influence of seeding date on growth, characteristic yield and chemical composition of Italian millet (Setaria italica) from April 20 to May 30, 2003(April 20, May 1, May 20 and May 30) in Jeju. A local variety was seeded on days to heading were lessened as seeding date was delayed. The plant height was longest when seeded on 1 May(131cm) than at the other seeding dates. Stem diameter, number of leaves, leaf length and leaf width had the similar trend with plant height. SPDA reading values were greater at earlier seedings. Fresh forage yield was greatest (43.28MT/ha) at 1 May seeding and decreased gradually before or after this seeding date. Dry matter yield, crude protein yield and total digestible nutrient (TDN) yield had nearly the same tendency with fresh forage yield. Crude protein, crude fat, NFE and TDN contents were greatest at 30 May seeding and then decreased earlier seedings. Crude ash and crude fiber content tended to decreased as seeding was delayed. Based on the these findings, optimum seeding date for forage production of Italian millet seems to be early May in Jeju island.

Effect of Shading Level of Nursing Bed on the Shoot Growth of Rooted Cuttings in Native Hydrangea serrata for. acuminata (육묘상의 차광정도가 자생 산수국 삽목묘의 신초생장에 미치는 영향)

  • Lee, Seung Youn;Lee, Sung Chun;Park, Sung Tae;Rhee, Jung Chul;Lee, Taek Joo;Kim, Kwang Jin;Lee, Jeong Sik
    • FLOWER RESEARCH JOURNAL
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    • 제16권3호
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    • pp.153-160
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    • 2008
  • This experiment was conducted to find out an adequate shading level (0, 55, 74, and 95%) on the shoot growth of rooted cuttings of native Hydrangea serrata for. acuminata. New shoot height (NSH), length and width of leaf, and stem diameter under 55% shading were the greatest. Net photosynthetic rate under 55% shading was the greatest, while intercellular $CO_2$ concentration was the least in this treatment. The greatest content of photosynthetic pigments (total chlorophyll, carotenoid) was observed in leaves grown under a 74%, followed by a 55% shading level. Leaf stomata were observed on the abaxial surface, but those on adaxial surface in all shading treatments were not observed. In 95% shading, decreased stomatal density and development were observed. Higher stomatal density and development, however, were observed in 55% shading. Therefore, it is concluded that a 55% shading level was the optimum for growth of new shoots of rooted cuttings of native H. serrata for. acuminata.