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        검색결과 9,514

        8063.
        2012.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this study, we compared the precipitable water vapor (PWV) data derived from the radiosonde observation data at Sokcho Observatory and the PWV data at Sokcho Global Positioning System (GPS) Observatory provided by Korea Astronomy and Space Science Institute, for the years of 2006, 2008, 2010, and analyzed the radiosonde seasonal, diurnal bias according to radiosonde sensor types. In the scatter diagram of the daytime and nighttime radiosonde PWV data and the GPS PWV data, dry bias was found in the daytime radiosonde observation as known in the previous study. Overall, the tendency that the wet bias of the radiosonde PWV increased as the GPS PWV decreased and the dry bias of the radiosonde PWV increased as the GPS PWV increased. The quantitative analysis of the bias and error of the radiosonde PWV data showed that the mean bias decreased in the nighttime except for 2006 winter, and in comparison for summer, RS92-SGP sensor showed the highest quality.
        8064.
        2012.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Kinematic global positioning system precise point positioning (GPS PPP) technology is widely used to the several area such as monitoring of crustal movement and precise orbit determination (POD) using the dual-frequency GPS observations. In this study we developed a kinematic PPP technology and applied 3-pass (forward/backward/forward) filter for the stabilization of the initial state of the parameters to be estimated. For verification of results, we obtained GPS data sets from six international GPS reference stations (ALGO, AMC2, BJFS, GRAZ, IENG and TSKB) and processed in daily basis by using the developed software. As a result, the mean position errors by kinematic PPP showed 0.51 cm in the east-west direction, 0.31 cm in the north-south direction and 1.02 cm in the up-down direction. The root mean square values produced from them were 1.59 cm for the east-west component, 1.26 cm for the south-west component and 2.95 cm for the up-down component.
        8065.
        2012.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Since the development of surface magnetic features should reflect the evolution of the solar magnetic field in the deep interior of the Sun, it is crucial to study properties of sunspots and sunspot groups to understand the physical processes working below the solar surface. Here, using the data set of sunspot groups observed at the ButterStar observatory for 3,364 days from 2002 October 16 to 2011 December 31, we investigate temporal change of sunspot groups depending on their Zürich classification type. Our main findings are as follows: (1) There are more sunspot groups in the southern hemisphere in solar cycle 23, while more sunspot groups appear in the northern hemisphere in solar cycle 24. We also note that in the declining phase of solar cycle 23 the decreasing tendency is apparently steeper in the solar northern hemisphere than in the solar southern hemisphere. (2) Some of sunspot group types make a secondary peak in the distribution between the solar maximum and the solar minimum. More importantly, in this particular data set, sunspot groups which have appeared in the solar southern hemisphere make a secondary peak 1 year after a secondary peak occurs in the solar northern hemisphere. (3) The temporal variations of small and large sunspot group numbers are disparate. That is, the number of large sunspot group declines earlier and faster and that the number of small sunspot group begins to rise earlier and faster. (4) The total number of observed sunspot is found to behave more likewise as the small sunspot group does. Hence, according to our findings, behaviors and evolution of small magnetic flux tubes and large magnetic flux tubes seem to be different over solar cycles. Finally, we conclude by briefly pointing out its implication on the space weather forecast.
        8066.
        2012.07 서비스 종료(열람 제한)
        In order to cope with the recent global warming and climate change that is projected to have a grave impact on agriculture worldwide, we will direct our focus on developing crops tolerant to multiple abiotic stresses including drought, cold and heat, with the following research activities conducted by three different research groups including an international research team at IRRI. 1) Development of heat/cold tolerant rice variety : Major genes conferring heat tolerance and cold resistance in rice will be identified by comparative transcriptome analyses and new molecular markers will be developed based upon these data. EMS mutagenesis and proteomics analyses will accompany this approach to supplement this gene identification and marker development efforts. Once reliable markers are obtained in this way, new varieties of heat/cold tolerant japonica rice will be bred through introgression of these genes. 2) Development of drought/heat tolerant rice variety : Through QTL mapping conducted on RILs between a drought resistant line and an elite line, genes conferring drought/heat tolerance will be identified and molecular markers will be developed using SNP/GBS genotyping methods. Using these markers, new rice varietis with drought/heat tolerance will be bred by employing marker assisted selection (MAS) as well as marker assisted backcross (MABC). 3) Identification of genes involved in multiple stress responses in ginseng and brassica : Molecular breeding of stress tolerance traits in ginseng and brassica is not well established to date. Taking advantage of the ginseng whole genome sequence data information and other comparative genomics approaches, members of the stress-response transcription factor family CBF/DREB will be identified and their functional analyses will be performed in ginseng and brassica using transcriptome profiling of both wild type and transgenic plants including the adventitious root-derived transgenic ginseng. Major Publications: - Lee, J., W. Jiang, et al. (2011). “Shotgun proteomic analysis for detecting differentially expressed proteins in the reduced culm number rice.” Proteomics 11(3): 455-468. - Ji, H., S. R. Kim, et al. (2010). “Inactivation of the CTD phosphatase-like gene OsCPL1 enhances the development of the abscission layer and seed shattering in rice.” The Plant journal 61(1): 96-106. - Chin JH, Gamuyao R, Dalid C, Bustamam M, Prasetiyono J, Moeljopawiro S, Wissuwa M, Heuer S (2011) Developing rice with high yield under P-deficiency: Pup1 sequence and application. Plant Physiology 156: 1-15. - Hong-Il Choi, Nam Hoon Kim et al. (2011) Development of Reproducible EST-derived SSR Markers and their application for genomics and breeding of Panax ginseng Journal of Ginseng Research 35(4): 399-412.
        8067.
        2012.07 서비스 종료(열람 제한)
        Hybrid sterility is one of the major barrier to the application of wide crosses in plant breeding and is commonly encountered in crosses between indica and japonica rice varieties. Ten mapping populations comprised of two reciprocal F2 and eight BC1F1 populations generated from the cross between Ilpumbyeo (japonica) and Dasanbyeo (indica) were used to identify QTLs and to interpret the gametophytic factors involved in hybrid fertility or sterility between two subspecies. Frame maps were constructed using a total of 107 and 144 STS markers covering 12 rice chromosomes in two reciprocal F2 and eight BC1F1 populations, respectively. A total of 15 main-effect QTLs and 17 significant digenic- epistatic interactions controlling spikelet fertility (SF) were resolved in the the entire genome map of F2 BC1F1 populations . Among detected QTLs responsible for hybrid ferility, four QTLs, qSF5.1 and and qS F5.2 on chromosome 5, qSF6.2 on chromosome 6, and qSF12.2 on chromosome 12 were identified as major QTLs since they were located at corresponding position in at least three mapping populations. Loci qSF5.1, qSF6.1 and qSF6.2 were responsible for both female and male sterility, whereas qSF3.1, qSF7 and qSF 12.2 affected the spikelet fertility only through embryosac factors, and qSF9.1 did through pollen factors. Five new QTLs identified in this study will be helpful for understanding the hybrid sterility and for breeding programs via inter-subspecific hybridization.
        8068.
        2012.07 서비스 종료(열람 제한)
        Hybrid sterility is one of the major barrier to the application of wide crosses in plant breeding and is commonly encountered in crosses between indica and japonica rice varieties. Ten mapping populations comprised of two reciprocal F2 and eight BC1F1 populations generated from the cross between Ilpumbyeo (japonica) and Dasanbyeo (indica) were used to identify QTLs and to interpret the gametophytic factors involved in hybrid fertility or sterility between two subspecies. Frame maps were constructed using a total of 107 and 144 STS markers covering 12 rice chromosomes in two reciprocal F2 and eight BC1F1 populations, respectively. A total of 15 main-effect QTLs and 17 significant digenic- epistatic interactions controlling spikelet fertility (SF) were resolved in the the entire genome map of F2 BC1F1 populations . Among detected QTLs responsible for hybrid ferility, four QTLs, qSF5.1 and and qS F5.2 on chromosome 5, qSF6.2 on chromosome 6, and qSF12.2 on chromosome 12 were identified as major QTLs since they were located at corresponding position in at least three mapping populations. Loci qSF5.1, qSF6.1 and qSF6.2 were responsible for both female and male sterility, whereas qSF3.1, qSF7 and qSF 12.2 affected the spikelet fertility only through embryosac factors, and qSF9.1 did through pollen factors. Five new QTLs identified in this study will be helpful for understanding the hybrid sterility and for breeding programs via inter-subspecific hybridization.
        8069.
        2012.07 서비스 종료(열람 제한)
        The HWC-line of rice showed wide compatibility with both indica and japonica cultivars, tall culm length, long and slender grain shape. For QTL analysis, two F2 populations were derived from the crosses between the HWC-line and each of two Korean variety, Dasanbyeo (Korean Tongil-type cultivar) and Hwacheongbyeo (temperate japonica cultivar), respectively. A total of 190 F2 plants were evaluated in each of two F2 populations. Eight agronomic characters were measured for QTL analysis in F2 populations and parents. Two molecular linkage maps were constructed. In the F2 population from cross between HWC-line / Dasanbyeo (HD) cross, 93 STS markers and 13 SSR markers were mapped on 12 chromosomes, covering a total length of 1942.6 cM, with an average distance of 18.33cM between adjacent markers. In the F2 population from HWC-line / Hwacheongbyeo (HH) cross, 28 STS markers, 29 SSR markers and 1 FNP marker were mapped on 11 chromosomes, spanning a total length of 925.53cM, with an average distance of 15.96cM between adjacent markers. In the F2 population from HD cross, 16 M-QTLs and 1 E-QTL were detected for culm length, spikelets per panicle, spikelet fertility, grain length, grain width, grain shape and 100 grains weight. 7 QTLs of spikelet fertility, grain length, grain width and grain shape were newly identified in this study. In the F2 population from HH cross, 15 M-QTLs were detected for culm length, panicle length, spikelet fertility, grain length, grain width, grain shape and 100 grains weight. 6 QTLs of culm length, grain length, grain width and grain shape were newly identified in this study. The QTLs identified in this study would provide basic information on putative functional genes related agronomic characters and facilitate breed new rice cultivar.
        8070.
        2012.07 서비스 종료(열람 제한)
        Heterosis describes the increased performance of F1 hybrid plants in terms of increased biomass, yield, vegetative growth rate, and tolerance against biotic and abiotic stresses as compared with their inbred parents. Two sets of rice materials, 166 RILs derived from a cross between Milyang 23 (Korean indica-type rice) and Tong 88-7 (japonica Rice), and BC1F1 hybrids derived from crosses between the RILs and the female parent, Milyang 23, were produced to identify QTLs for heterosis of yield and yield-related traits. The QTLs were detected from three different phenotype data sets including the RILs, BC1F1 hybrids, and mid-parental heterosis data set. A total of 57 QTLs were identified for nine traits. Of eight QTLs detected for yield heterosis, five overlapped with other heterosis QTLs for yield-related traits such as spikelet number per panicle, days to heading, and spikelet fertility. Four QTLs for yield heterosis, gy1.1, py6, gy10, and py11, were newly identified in this study. We identified a total of 17 EpQTLs for yield heterosis that explain 21.4 ~ 59.0 % of total phenotypic variation, indicating that epistatic interactions may play an important role in heterosis.
        8071.
        2012.07 서비스 종료(열람 제한)
        Farmers have use phosphate fertilizer to provide sufficient yields. However, overuse of phosphorus accumulate in soil and causes soil and water pollution. We evaluated the phosphate acquisition and growth characteristics of OsPT1 transgenic rice (OsPT1-OX, over-expressing the high affinity phosphate transporter 1) in high phosphate soils with different level of nitrogen fertilizer treatment to investigate removing ability of excessive phosphate from soil. OsPT1-OX had shorter culm length but more tillers than those of wild-type plants in each soil conditions. Phosphate content per dry weight of OsPT1-OX was 1.8 times higher than that of wild-type under control fertilizer treated conditions. Although the dry weight of OsPT1-OX was not different from that of wild-type plants, whole plant phosphate content was 1.7 times higher than that of wild-type plants under control fertilizer conditions. Tiller number and phosphate content per dry weight of wild-type plants increased following high levels of phosphate application but did not change by following additional nitrogen application. Tiller number and phosphate content per dry weight of OsPT1-OX did not change under the high phosphate condition, but increased following nitrogen application under similar conditions. Whole plant phosphate content was highest under high nitrogen and high phosphate application conditions. These results suggest that OsPT1-OX may reduce phosphate content in soils containing excess phosphate and may be further effective under high nitrogen condition.
        8072.
        2012.07 서비스 종료(열람 제한)
        The use of functional markers, it is expected to make direct identification about genetic diversity at DNA level and overcome the problem of recombination /linkage. These markers can be used to identify interesting alleles in a breeding program and indirectly select for the trait, saving money, time and labor. Bacterial blight of rice caused by Xanthomonas oryzaepv. Oryzae is a destructive disease in rice production worldwide. No bactericide is effective to control the bacterial blight disease yet. Xa3, which is a gene conferring resistance to BB of the rice plant has been previously characterized by map-based cloning. We have cloned and sequenced the Xa3/xa3 gene in Korean cultivar, Hwayoung, Ilmi and Goun with gene specific primers. Our work detected polymorphisms and PCR-based allele specific SNP markers were developed. Susceptible or resistant individuals from an F2 population developed from across between Milyang244 and Ilmi, Korean germplasms and near isogenic lines carrying BB resistance genes were screened with allele specific markers. We found that the genotype completely matched their phenotype to BB using ASP-primers. These markers could be effective to marker-assisted selection for the Xa3 gene in rice breeding programs.
        8073.
        2012.07 서비스 종료(열람 제한)
        Tocopherols (α-, β-, γ- and δ-tocopherols) represent a group of lipophilic antioxidants which are synthesized only by photosynthetic organisms. It is widely believed that protection of pigments and proteins of photosynthetic system and polyunsaturated fatty acids from oxidative damage caused by reactive oxygen species (ROS) is the main function of tocopherols. In the present study, NtTC, which encodes a tobacco tocopherol cyclase ortholog, was cloned and characterized. Compared with control plants, NtTC transgenic rice showed higher tolerance to drought stress, and total tocopherol content increased by 52 % in leaf. Additionally, total antioxitant activity of NtTC transgenic lines was increased significantly by 19%. These results demonstrate that over-expressing NtTC could improve the tolerance to abiotic stress in rice, and tocopherols play a crucial role in the protection of oxidative stress.
        8074.
        2012.07 서비스 종료(열람 제한)
        The molecular processing of upstream regulation of Pi response genes during Pi starvation remains inadequately understood. several transcription factor have been studied that appear to regulate subsets of the responses to Pi stress either positively or negatively. MYB gene is responsive to one or multiple type of hormone and stress treatments. In this study, cDNA of the MYB have been cloned, and we generated Rice overexpressing plants for characterization of these genes .OsMYB gene’s functions focused on phosphate conditions with rice and Arabidopsis transgenic plants. We selected 30 - T1 transgenic lines from T0 transgenic rices. those are shown high Pi content. The Pi contents of shoots part of transgenic plants were shown 10~20% increased Pi contents than WT, whereas roots have 30% increased Pi contents. As a result, OsMYB genes affect Pi uptake in plants. To investigate interactions between MYB proteins and phosphate signaling related genes.
        8075.
        2012.07 서비스 종료(열람 제한)
        Pollen development in flowering plants is regulated by a comprehensive pattern of genes. One way to produce hybrid rice based on nuclear male sterility is to find out firstly the potential promoters that function specifically in anthers since it is a specific site for transcription initiation and play key roles for the spatial and temporal expression of the genes. To implement this objective, we were selected promoter region of 16 genes based on the expression pattern of microarray and then those were introduced into the promoterless final destination vector which containing the GFP and GUS reporters genes. The resulting twelve vectors were transformed into monocotyledonous rice (Oryza sativa L) and a dicotyledonous Arabidopsis as heterologous system. Minimum 20 plants for each vector were analyzed by histochemical GUS assay at the flowering stage in Arabidopsis. 9 vectors out of 12 vectors constructed were expressed exclusively at the anther, especially in pollen, however one vector exhibited expression in stigma. For rice, T-DNA insertion were confirmed with specific primers in each promoter and GFP region. All T0 transgenic plants contained T-DNA insertion in their genome. This study would provide valuable information for biotechnological application for the induction of male sterility in plants.
        8076.
        2012.07 서비스 종료(열람 제한)
        In this study, we were conducted the construction of the framework map using SSR markers in the F2 population derived from a cross between waxy corn inbred line (02S6140) and sweet corn inbred line (KSS22), and also identifying of QTLs associated with eating quality traits by employing genetic linkage map of F2:3 population. The linkage map was constructed using 295 SSR markers on the 158 F2 individuals derived from a cross of 02S6140 and KSS22. The map comprised a total genomic length of 2,626.5cM in ten linkage groups and an average distance between markers of 8.9cM. Chi-square test revealed that 254 markers (86.1%) associating with all ten chromosomes exhibited a segregation of 1:2:1 Mendelian ratio. A total of 10 QTLs each for pericarp thickness (PER), amylose content (AMY), dextrose content (DEX), and sucrose content (SUC) were detected in the 158 F2 families. The number of QTL per each trait was ranged from 2 to 4, and also phenotypic variance was ranged from 4.26 to 30.71%. For PER, 4 QTLs were found to be controlled by four genomic regions at locations chromosomes 4, 5, 8, and 9 contributing 10.43, 6.71, 6.74, and 7.79% of phenotypic variance, respectively. While 2 QTLs for AMY, DEX, SUC traits, were found to be controlled by two genomic regions at locations chromosomes 4, 6, 8, and 9 contributing between 4.26 and 30.71% of phenotypic variance, respectively. Among them, 4 QTLs, such as qAMY4 (10.43%), qAMY9 (19.33%), qDEX4 (21.31%), and qSUC4 (30.71%), may be considered as a major QTLs, while the remaining six QTLs might be regarded as minor QTLs. In our study, qAMY9 for amylase content was detected on chromosome 9 in marker intervals phi027-umc1634, which was the same locus as encoding wx1 gene. Thus qAMY9 may be thought very useful molecular marker for selecting amylase content trait. The other QTLs may be thought very useful molecular marker for eating quality traits. The resulting genetic map will be useful in dissection of quantitative traits and the identification of superior QTLs from the waxy hybrid corn, and also this study may provide valuable information for the further identification and characterization of genes responsible for eating quality-related traits in waxy corn and sweet corn.
        8077.
        2012.07 서비스 종료(열람 제한)
        In order to clarify the chromosomal location of quantitative trait loci (QTL) associated with the yield and agronomic traits in waxy corn and sweet corn (Zea maysL.), we were conducted identifying of QTLs associated with yield and agronomic traits by employing genetic linkage map of F2:3 population. A total of 14 QTLs each for days to silking (DTS), plant height (PH), ear height (EH), ear height ratio (ER), ear length (L-Ear) and kernel setting length (L-Sear) were detected in the 158 F2 families. The number of QTL per each trait was ranged from 1 to 6, and also phenotypic variance was ranged from 3.55 to 16.86%. For DTS, one QTLs was found to be controlled by genomic regions at locations chromosomes 1 contributing 9.21% of phenotypic variance. While three QTLs for PH, were found to be controlled by 3 genomic regions at locations chromosomes 1 and 2 contributing 6.68, 6.85 and 8.17% of phenotypic variance, respectively. For EH, six QTLs were found to be controlled by 6 genomic regions at locations chromosomes 1, 7, 8 and 10 range from 3.55 to 11.44% of phenotypic variance. The one QTLs for ER was found at locations chromosomes 1 contributing 7.25% of phenotypic variance. For L-Ear, two QTLs were found to be controlled by 2 genomic regions at location chromosome 7 and 10 contributing 7.40 and 11.63% of phenotypic variance, respetively. The one QTLs for L-Sear was found at locations chromosomes 3 contributing 16.86% of phenotypic variance. Among them, three QTLs, such as qEH8 (11.44%), qLEar10 (11.63%), and qLSear3 (16.86%) may be considered as a major QTLs, while the remaining 11 QTLs might be regarded as minor QTLs. This study may provide valuable information for the further identification and characterization of genes responsible for agronomic traits in waxy corn and sweet corn.
        8078.
        2012.07 서비스 종료(열람 제한)
        Ionizing radiation is known to cause chromosomal alterations such as inversions and deletions and affects gene expression within the plant genome. To monitor the genome-wide transcriptome changes by ionizing radiation, we used rice Affimetrix GeneChip microarray to identify genes that are up- or down regulated by gamma-ray (200 Gy, 60Co source), cosmic-ray and ion beam (40 Gy, 220 MeV carbon ion). The overall expression patterns between gamma-ray and ion beam were similar but cosmic-ray was regulated differently. Combined results from all 3 radiations identified 27 up-regulated genes and 188 down regulated genes. These results mean the induction of similar mechanism changes in treatments of gamma ray and ion beam. However the different expression in treatment of cosmic-ray might be due to the other environmental conditions. Among the commonly up- or down- regulated genes, we chose highly up- or down- regulated several genes and confirmed its regulation in response to ionizing radiation exposure by RT-PCR analysis. Moreover, we showed that specific co-expression networks of candidate radio marker genes by ARACNE algorithm. Our results present profiles of gene expression related to different ionizing radiation and marker gene to predict sensitivity to ionizing radiation, such as GS (glutelin subunit) and FBX322.
        8079.
        2012.07 서비스 종료(열람 제한)
        The role of an expansin gene (IbEXP1) in the formation of the storage root (SR) was investigated by expression pattern analysis and characterization of IbEXP1-antisense sweetpotato (Ipomoea batatas cv.Yulmi) plants in an attempt to elucidate the molecular mechanism underlying SR development in sweetpotato. Transcript level of IbEXP1 was high in the fibrous root (FR) and petiole at the FR stage, but decreased significantly at the young storage root (YSR) stage. IbEXP1-antisense plants cultured in vitro produced FRs which were both thicker and shorter than those of wild-type (WT) plants. Elongation growth of the epidermal cells was significantly reduced, and metaxylem and cambium cell proliferation was markedly enhanced in the FRs of IbEXP1-antisenseplants, resulting in an earlier thickening growth in these plants relative to WT plants. There was a marked reduction in the lignification of the central stele of the FRs of the IbEXP1-antisense plants, suggesting that the FRs of the mutant plants possessed a higher potential than those of WT plants to develop into SRs. IbEXP1-antisense plants cultured in soil produced a larger number of SRs and, consequently, total SR weight per IbEXP1-antisense plant was greater than that per WT plant. These results demonstrate that SR development was accelerated in IbEXP1-antisense plants and suggest that IbEXP1 plays a negative role in the formation of SR by suppressing the proliferation of metaxylem and cambium cells to inhibit the initial thickening growth of SRs.
        8080.
        2012.07 서비스 종료(열람 제한)
        Organ size control is a fundamental developmental processes for higher plants as well as a promising target trait for molecular breeding in crop plants. Genetic mechanisms how plant organs grow to a certain size remains still unclear. Here we present the identification and characterization of a genetic mutant, big flower1-1 (bif1-1) in Arabidopsis that exhibits bigger organ size primarily due to increased cell size. Genetic analysis indicated that it is a single, semi-dominant mutation. Phenotypic analysis showed that bif1-1 exerts pleiotropic effects: it caused bigger seed size, bigger seedling, bigger leaf, thicker stem, increased trichome branching, smaller fruit, and bigger pollen. Microscopic analysis suggested that the bigger organ size in bif1-1 mutant is primarily attributed to increased cell size. Gene expression analysis indicated that most of growth-control genes tested were not altered in bif1-1 mutant. Instead, expression of ARGOS and auxin-inducibility of ANT were reduced in bif1-1 mutant. Our ongoing positional on the corresponding gene would not only shed light on the molecular mechanisms how plants adopt final organ size but also provide a promising genetic resource for genetic engineering of flower- and seed-size in crop plants.