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        검색결과 37

        2.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Karyotype analysis is a major work in the process of triploid abalone production for the purpose of productivity and quality improvement. However, the metaphase spreads for karyotype analysis have been prepared just from the larvae at trochophore stage, which has restricted the spectrum of sample correction inhibiting more efficient analysis. Here, we investigated the feasibility of preparing metaphase spreads from the larvae at veliger stage that is the next developmental stage of trochophore. For this, diploid and triploid larvae at trochophore and veliger stages from Pacific abalone (Haliotis discus hannai ) were subjected to metaphase spread preparation and its efficiencies were measured and compared each other. As the results, although the efficiencies of metaphase spread preparation were significantly lower in the larvae at veliger stage compared to the ones at trochophore stage regardless of ploidy status, we found that the preparation of metaphase spreads, which showed the clear chromosomal images containing the normal number of chromosomes, was possible from the veliger stage larvae. On the other hands, all larvae used in this study regardless of developmental stage and ploidy did not show colchicine sensitivity. Moreover, no significant difference was observed in cell cycle distribution of the cells comprising larvae between two developmental stages regardless of ploidy status. These suggested that the details of protocol to prepare metaphase spreads from abalone larvae should be optimized depending on its developmental stages. Taken together, we demonstrated the feasibility of preparing metaphase spreads from H. discus hannai veliger stage larvae for karyotype analysis.
        4,000원
        3.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, pitch crosslinked by oxygen function groups was made into activated carbon (AC) and pore structure was observed. The oxygen functional groups were introduced by the addition of waste PET for pitch synthesis. Activation agent ratios used to obtain the AC during the activation process were 1:1, 1:2 and 1:4 (pitch:KOH, w/w). The oxygen content in the prepared pitch was characterized by elemental analysis. Also, the molecular weight of pitch was investigated by MALDITOF. Specific surface area and micropore volume of the prepared AC were determined by the argon adsorption–desorption analysis and calculated using the Brunauer–Emmett–Teller and Horvath–Kawazoe equations, respectively. Micropore fraction of PET-free AC was smaller than that of PET-added AC. At high activation agent ratio, mesopores were created when the micropore structure collapsed. However, in the PET-added AC, due to the oxygen crosslinking effect, the micropore structure and micropore size were maintained even at a high activation agent ratio. Therefore, PET AC was found to have a higher micropore fraction than that of PET-free AC.
        4,000원
        7.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This research is to evaluate the mechanical performance of different types of Hot Mix Asphalt (HMA) pavement cells prepared for MN/Road field testing section through an extensive experimental analysis of air voids and simple statistical evaluation tools (i.e. hypothesis test). METHODS: An extensive experimental work was performed to measure air voids in 82 asphalt mixture cores (238 samples in total) obtained from nine different types of road cell located in MN/Road testing field. In order to numerically and quantitatively address the differences in air voids among the different test Cells built in MN/Road, a simple statistical test method (i.e. t-test) with 5% significance was used. RESULTS: Similar trends in air voids content were found among the mixtures including conventional HMA, Reclaimed Asphalt Pavement (RAP) and Warm Mix Asphalt (WMA) combined with taconite aggregate this provides support to the use of RAP and WMA technology in the constructions of asphalt pavement. However, in case of acid modified HMA mixtures, significant differences in air void content were observed between on the wheel path and between wheel path location, which implies negative performances in rutting and thermal cracking resistances. Conclusions : It can be concluded that use of RAP and WMA technology in the construction of conventional asphalt pavement and the use of PPA (Poly Phosphoric Acid) in combinations with SBS (Styrene Butadiene Styrene) in asphalt binder production provide satisfactory performance and, therefore, are highly recommended
        4,300원
        8.
        2013.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        고준위방사성폐기물 처분장의 완충재로 고려되고 있는 자연산 벤토나이트에 대해서 기존의 물리·화학적 및 광물학적 성질 외에 생물학적 특성을 살펴보았다. 국내산 ‘경주벤토나이트’를 대상으로 만든 현탁액을 영양배 지 세럼병에서 일주일 이상 숙성시키며 시간에 따른 벤토나이트의 변화를 관찰하였다. 영양배지에서 활성화 된 벤토나이트는 고체 시료뿐만 아니라 용액도 함께 변하였다. 용존황산염 수용액으로부터 검은색의 미립자 황화물이 생성되기 시작하였으며, 시료를 채취하여 배양한 결과 4 종류의 황산염환원박테리아(SRB)가 자체 생존하고 있음이 확인되었다. 이러한 결과는 벤토나이트 분말시료 내에 황산염환원(혹은 금속환원)박테리아 가 고착 및 서식하고 있음을 말해주는 것으로, 이는 지하의 환원환경 조건하에서 완충재 내외부에 장기적으로 생지화학적 영향이 발현될 가능성이 있음을 의미한다.
        4,000원
        11.
        2017.05 서비스 종료(열람 제한)
        Background : Licorice has been used as a source of medicine and a food material in East-Asia. Recently, demand for licorice increased in market due to a growing interest in health. Thus we conducted breeding research to solve the problems associated with domestically cultivated licorice such as low productivity and low glycyrrhizin content. Methods and Results : We crossed European licorice (G. glabra L.; female parent) and Chinese licorice (G. uralensis Fisch; male parent) in the greenhouse in May 2007. In September 2007, crossed and germinated seeds were retrieved and sown in the greenhouse. In June 2008, stolons were separated from the F1 licorice seedlings and cultivated, resulting in 32 clonal lines of interspecific hybrids. Among them we selected good lines and then conducted the replicated yield trials (RYT) in 2012-2013 and local adaptability test (LAT) in 2014-2015. The results, GLYES9 showed that was elect of stem, oblong of leaf shape, red-brown of root color. Glycyrrhizin conten of GLYES9 (3.0%) was higher than G. uralensis (1.9%) at four regions from 2014 to 2015. GLYES9 was less than 10% in the desease of brown spot (G. uralensis was more than 30%). The root yield of GLYES9 was 4.31 ton per hectare, which was increased 193% compared with a check variety of G. uralensis. Therfore, we named GLYES9 as new cultivar ‘Dagam’. Conclusion : Depending on the above results, we have developed a new licorice cultivar ‘Dagam’ by the medicinal crop breeding team of National Institute of Horticulture and Herbal Science, RDA, in 2015. It showed brown spot disease resistant, high-glycyrrhizn content and high-yielding than colleted Glycyrrhiza spp.
        12.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of 1.35 ± 0.04 mm and an oil globule diameter of 0.32 ± 0.02 mm. The fertilized eggs hatched 67–75 h after fertilization in water at 20 ± 0.5°C. The total length (TL) of the hatched larvae was 3.62 ± 0.16 mm. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was 4.72 ± 0.07 mm. At 40 DAH, the juveniles had grown to 30.44 ± 4.07 mm in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3–4 vertical stripes appeared. At 45 DAH, the juveniles were 38.67 ± 5.65 mm in TL and 10.10 ± 0.94 mm in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin.
        13.
        2015.07 서비스 종료(열람 제한)
        Seed color is an important factor affecting physiological and developmental process in wheat. One of the plant pigments, anthocyanins are a group of flavonoid compounds well known as pigments responsible for blue, purple, red, or yellow coloration of plant tissues. In this study, we investigated the pigmentation of purple and yellow color seed according to wheat grain developmental stages. The contents of anthocyanin and chlorophyll in the purple and yellow seeds were measured. Chlorophyll contents were changed similarly in both purple and yellow color seed, and no significant difference was observed between them. In purple color seed, the content of anthocyanin was significantly induced compared with yellow color seed. The individual anthocyanin components were investigated by ultra performance liquid chromatography (UPLC). Cyanidine-3-glucoside (C3G) and peonidine-3-glucoside (P3G) were detected as predominant anthocyanin in purple color wheat. To investigate whether structural genes in anthocyanin biosynthesis were involved in the trait differences between purple and yellow color seed, we examined the expression of anthocyanin biosynthesis-related genes (CHS, CHI, F3H, DFR, ANS, UFGT) and MYB transcription factor in developing wheat grains by using qRT-PCR. This study indicates that the expression of anthocyanin biosynthesis-related genes and MYB transcription factors correlate with anthocyanin levels of grain.
        14.
        2015.07 서비스 종료(열람 제한)
        Space has many distinguishable characteristics from earth such as strong cosmic radiation, microgravity, supervaccum and weak magnetic field. For this reason, space environments can be used an efficient mutagen for plant breeding nowadays. To identify the affected genes by condition in space with outer space, Brachypodium seeds were placed in the Russia Segment (RS) Biorisk module of International Space Station (ISS). Brachypodium distachyon is a model system for temperature grass, because they represent the characteristics for annual winter grass. Seeds and organs of plants carried by satellite or spacecraft to space can be genetically mutated by exposing space environment. We performed a duplicated RNA sequencing to profile the differentially expressed genes. As a results, about 700 genes were upregulated and 250 genes were downregulated by cosmic environments, respectively. In the molecular function category, protein kinase and transcription activity related genes were upregulated. Among the many transcription factors (TFs), stress related TFs such as ERF, NAC and WRKY were differentially expressed in space exposed samples. In the future, their expression will be identified by using qRT_PCR.
        15.
        2014.07 서비스 종료(열람 제한)
        Gamma irradiation has been used as a tool for plant mutation breeding to select new cultivar with improved characteristics. Generally, the irradiation of seeds with high doses of gamma rays disturbs the synthesis of protein, hormone balance, and enzyme activity. And also, high dose of gamma rays to reduce plant height, number of tiller, and root length, although the effect of gamma-irradiated plants may depend on the species and cultivar or stress conditions. Biological effects of radiations can be divided into two types according to dose range and periods of exposure. Acute irradiation represents exposure to high-dose of irradiation over short period time, whereas the chronic irradiation is comprised of exposure to low doses of radiation over extended period of time. To compare the effects of acute and chronic exposure to ionizing radiation on two wheat cultivars (K4191 and Geumgangmil), we measured their germination rate, seedling height, and root length. In order to understand the influence of antioxidant-related genes and DNA repair-related genes, we used qRT-PCR methods to identify their expression levels. To study the behavior of a radiation-induced free radical, gamma-irradiated seeds were used for ESR spectroscopy. Plant growth pattern was showed positive correlation with ESR results. This study indicates that low level chronic radiation exposure is even more serious effects than short doses of high level radiation according to different wheat cultivar.
        16.
        2014.07 서비스 종료(열람 제한)
        Chronic gamma irradiation can be used an alternative mutation breeding methods for induction of many useful mutants. Seedlings of purple-colored wheat plants were irradiated with wide range doses of chronic gamma-rays (20, 25, 30, 40, 50, 70, 100, 125, 150, 200, 250, 300 Gy) during 6 weeks at gamma-phytotron in the Korea Atomic Energy Research Institute, respectively. To identify the biological responses purple-colored wheat, we examined the plant height, chlorophyll, carotenoid and total anthocyanin contents in leaf. Plant growth, chlorophyll and carotenoid contents in leaf were decreased when the dose rate increased. Anthocyanin contents were increased with the increase of the radiation dose until 50 Gy treatment. To confirm the real contents of anthocyanin, we also investigated cyanidin-3-glucoside in purple-colored wheat leaf by using UPLC analysis. These results indicate that anthocyanin accumuation was observed under chronic gamma irradiation.
        17.
        2013.07 서비스 종료(열람 제한)
        Soybean mosaic virus (SMV), a member of Potyviridae family, is one of the most typical viral diseases and results in yield and quality loss of cultivated soybean. Due to the depletion of genetic resources for resistance breeding, a trial of genetic transformation to improve disease resistance has been performed by introducing SMV-CP and HC-Pro gene by RNA interference (RNAi) method via Agrobacterium-mediated transformation. Transgenic plants were infected with SMV strain G5 and investigated the viral response. As a result, two lines (3 and 4) of SMV-CP(RNAi) transgenic plants and three lines (2, 5 and 6) of HC-Pro(RNAi) transgenic plants showed viral resistance. In genomic Southern blot analysis, most of lines contained at least one T-DNA insertion in both SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants. Subsequent investigation confirmed that no viral CP and HC-Pro gene expression was detected in two SMV-resistant lines of SMV-CP(RNAi) and three lines of HC-Pro(RNAi) transgenic plants, respectively. On the other hand, non-transgenic plants and other lines showed viral RNA expression. Viral symptoms affected seed morphology, and clean seeds were harvested from SMV-resistant line of SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants. In addition, strong viral gene expression was detected from seeds of SMV-susceptible non-transgenic plants and SMV-susceptible transgenic lines. When compared the viral resistance between SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants, soybean transgenic plants with the HC-Pro gene using RNAi strategy showed much stronger and higher frequency of viral resistance.
        18.
        2012.09 KCI 등재 서비스 종료(열람 제한)
        Citrus is one of the major fruits produced in Korea. There are about 20 species mainly grown in Jeju Island, Korea. Four representative species, which are quite different in the shape of leaf and the taste of fruit, were selected and were used to profile the transcriptomes. These species are ‘Miyagawa Wase’ (C. unshiu Marcov.) satsuma mandarin, ‘Kiyomi’ (C. unshiu Marcov. × C. sinensis) mandarin hybrid, ‘Dangyuja’ (C. grandis) and ‘Natsudaidai’ (C. natsudaidai). Classification of the up-regulated and down-regulated genes using the Cluster of Orthologous Groups of proteins (COG) database reveals that the number of genes included in each group differed significantly among the four species. Several genes that showed significant differences in expression on the microarray were selected and their expression patterns were examined by reverse transcription- ploymerase chain reaction. Metabolic genes such as tyrosine decarboxylase and β-glucosidase ligase were found to be highly expressed in Miyagawa Wase, relative to other species. On the other hand, the expression level of mannose phosphate isomerase was lower in Miyagawa Wase. An efflux pump gene was found to be up-regulated in Kiyomi, whereas cinnamyl-alcohol dehydrogenase was down-regulated. β-carotene 15,15’-dioxygenase, which is involved in the vitamin metabolism, was up-regulated in Natsudaidai. Interspecific differentiations of gene expression are analyzed in terms of the metabolic pathways and their possible roles in citrus species.
        19.
        2012.07 서비스 종료(열람 제한)
        Korean soybean variety Kwangan was transformed with coat protein (CP), helper component-proteinase (HC-Pro), and ABRE binding factor 3 (ABF3) genes using highly efficient soybean transformation system. Among these genes, CP and HC-Pro were transformed using RNAi technology. Transgenic plants with CP were confirmed for gene introduction and their expression using PCR, real-time PCR, RT-PCR, Southern blot, and Northern blot. To investigate the response of viral infection with CP, T1 plants were inoculated with SMV-infected leaves and confirmed the existence of mosaic symptom in both leaves and seeds. Two transgenic lines with CP were highly resistant to SMV with clear leaves and seeds while SMV-susceptible lines showed mosaic symptom with seed mottling. The transcript levels of T1 plants with CP were also determined by northern blot, suggesting that SMV-resistant T1 plants did not show viral RNA expression whereas SMV-susceptible T1 plants showed viral RNA expression. Currently, the response of viral infection with HC-Pro is investigating to produce SMV-resistant soybean transgenic plants, and the physiological experiment with ABF3 is also carrying out to produce drought-tolerant soybean transgenic plants.
        20.
        2012.03 KCI 등재 서비스 종료(열람 제한)
        Wild rice might have previously unidentified genes important for disease resistance and stress tolerance in response to biotic and abiotic stresses. A set of subtractive library was constructed both from leaves of wild rice plants, Oryza grandiglumis (CCDD, 2n=48), treated with fungal elicitor and from wounded leaves. A partial fragment that was homologous to PR10 genes from other plant species was identified via suppression subtractive hybridization and cDNA macroarray. The obtained full-length cDNA sequence (OgPR10) contains an open reading frame of 480 bp nucleotide, encoding 160 amino acids with a predicted molecular mass of 16.944 kDa and an isoelectric point (pI) of 4.91. The multiple alignment analyses showed the higher sequence homology of OgPR10 with PR10 genes identified in rice plants at amino acid level. The OgPR10 mRNA was not expressed by treatment with wounding, jasmonic acid, and salicylic acid, but markedly expressed in leaves treated with protein phosphatase inhibitors cantharidin and endothall, and yeast extract. In addition, the expression of OgPR10 mRNA was induced within 72 h after treatment with probenazole, one of well-known chemical elicitors, and reached the highest level at 144 h. Heterologous expression of OgPR10 caused growth inhibition and seedling lethality in E. coli and Arabidopsis, respectively. Chemically induced OgPR10 expression with glucocorticoid-mediated transcriptional induction system further reconfirmed its lethality on Arabidopsis seedling. In addition, OgPR10-expressing rice plants, Oryzae sativar were resistant against the infection of rice blast fungus, Magnaporthe grisea. These results indicate that OgPR10 is involved in probenazole- and microbe associated molecular patterns-mediated disease resistance responses in plants and is a potential gene for developing disease resistance crop plants.
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