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        검색결과 9,767

        9683.
        1999.09 KCI 등재 서비스 종료(열람 제한)
        Reverse transcription and polymerase chain reaction (RT-PCR) assay was used to detect SMV strains. A pair of oligonucleotide primers were designed to include the cylindrical inclusion (CI) coding region between 4,176 to 5,560 nt. Amplification from the total RNA extracted from infected plants with SMV yielded a 1,385 bp DNA fragment. RT-PCR was shown to be 103 times more sensitive than the ELISA assay and it could detect a virus in 10-6 dilution. Restriction enzyme analysis of RT- PCR products using EcoR I showed that SMV isolates were classified into six groups according to the patterns of restriction fragments.
        9684.
        1999.09 KCI 등재 서비스 종료(열람 제한)
        Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA3 ) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.
        9685.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        Trinexapac-ethyl[ 4-(cyclopropyl- α -hydroxy-methylene)-3,5-dioxocyclohexane carboxylic acid ethylester] is a growth-retardant for plants by inhibiting a key step in biosynthesis of GA. A treatment of trinexapacethyl generally induces a reduction in vegetative growth and also inhibits heading. In addition, the trinexapacethyl was known to enhance the freeze-tolerance in annual bluegrass, however, the mechanism is not known yet. One possible reason for the enhanced freeze-tolerance may be the antifreeze protein known to be accumulated in intercellular space of the leaf during cold acclimation. In order to see the possible in-duction of the synthesis of antifreeze proteins by trinexacpacethyl, the apoplastic proteins extracted from Kentucky bluegrass treated with trinexapacethyl were analyzed by SDS-PAGE and the presence of the antifreeze protein was observed. In addition, western analysis showed the identity of the protein induced by both a cold acclimation and a trinexapacethyl treatment. It appears that an enhanced freeze-tolerance of the turf grass by trinexapacethyl is due to the synthesis and/or accumulation of the antifreeze protein similar to the enhanced freeze tolerance induced by cold acclimation
        9686.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        Morphological alteration of floral organ development in rice affected by chilling stress was examined. Three varieties of rice were grown under natural conditions and subjected to 12~circC for 3 or 6 days starting from the ineffective tillering stage, before heading stage and returned to natural condition. Headings were delayed by a 6 day chilling treatment. After heading the panicles were collected and examined for any possible alteration in floral organ development. It appears that there were some differences in sensitivity to chilling stress and degree of injury depending on treatment stages and variety. Chuchungbyeo was the most frequent in producing abnormal flowers among the three varieties examined. Meiosis stage was shown to be the most vulnerable to chilling stress in both Chuchungbyeo and Ilpumbyeo and young panicle differentiation stage was the frequent stage to alter flower development in response to chilling stress only in Chuchungbyeo. It was confirmed that abnormalities occurred in pollen due to chilling stress is a major factor leading to low yield, but to some extent the alterations in carpel development may playa certain role in determining a total yield in response to chilling stress at the reproduction stage in rice. There were abnormalities like extra stigmata, extra lemma, double ovary as well as abnormal anther formation in response to chilling stress. Further studies of the phenocopy observed in rice floral development may be useful for an understanding of the resistance against chilling injury during reproductive stages in rice.
        9687.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        Volatile flavor compounds from perilla leaves were extracted and analyzed with different methods, head-space analysis (HS), simultaneous steam distillation and extraction (SDE) , and solvent extraction (SE), and to compare their efficiencies for quick analysis. Over 30 volatile compounds were isolated and 28 compounds were identified by GC/MSD. Major compound was perillaketone showing the compositions of which were 92% in SDE method, 86% in headspace analysis, and 62% in solvent extraction method. For quick evaluation of leaf flavor in perilla, it was desirable because the headspace analysis method had a shorter analyzing time and smaller sample amount than the other methods.
        9690.
        1999.03 KCI 등재 서비스 종료(열람 제한)
        Oh, Myung-Ki. 1999. Negative Polarity Licensing in Negated Because-clauses. Studies in Modern Grammar 15, 139-155. In this paper I`ll argue that NPI licensing in negated because-clauses can be properly accounted for, only if a causal statement can be captured as a combination of the antecedent, the consequent, and the corresponding negative counterfactual. In this context, this paper shows that NPIs in because-clauses can be explicitly licensed through the steps of derivation of the truth of negative because-clauses.
        9691.
        1999.03 KCI 등재 서비스 종료(열람 제한)
        A set of rice recombinant inbred lines was developed from a cross between a Tongil type variety, Nonganbyeo, and an indica variety, BG276, by the single seed descent method. The number of the lines in the population was 272. All the agronomic characters studied except ADV (alkali-digestion value) showed continuous variation among the RILs, implying that their inheritance mode should be quantitative. The patterns of the variation in the RILs were either normal or skewed distribution. ADVs of RILs were segregated into two groups with 1:1 ratio, indicating that ADVs in this KIL population might be controlled by one major gene. Transgressive variations were also observed in all characters. Heritability values of the characters varied from 0.488 in brown/rough rice ratio to 0.895 in alkali-digestion value. In the analysis of genotypic and phenotypic correlations, the character of yield was positively correlated with 8 different agronomic characters. The number of panicles per hill was negatively correlated with culm length, panicle length, and number of spikelets per panicle. Grain length was positively correlated with grain width, grain thickness, grain length/width ratio, white belly, ADV, and amylose. However, grain length/width ratio was negatively correlated with grain width. White core was also negatively correlated with white belly and ADV.
        9692.
        1999.03 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to determine the effects on rice growth, yields and soil improvement under the different nitrogen levels in machine-transplanted rice after plowing at the fruiting stage of milk vetch. The fresh weight of milk vetch at plowing time was 20.95 ton/ha. In dry weight, T-N and C/N were 1.58%, 21.8%, respectively. Organic matter, total nitrogen and exchangeable calcium of soil after the experiment in the plot of milk vetch were higher than those before the experiment. Leaf area and dry weight of rice plants at heading date increased as nitrogen level increased. The number of panicle and spikelets per ~textrmm2 were not different except for the 110 kg/ha nitrogen level plot with milk vetch. Brown rice yield ranged from 5.45 to 6.08 ton/ha, in creasing with increased nitrogen level. So the yield increased by 1% at 77 kg/ha nitrogen level, 7% at 110 kg/ha nitrogen level plot with milk vetch compared with conventional level (rice straw 5.4 ton/ha and nitrogen 110 kg/ha).
        9693.
        1998.12 KCI 등재 서비스 종료(열람 제한)
        The sesaminol glucosides in 80% EtOH extract from sesame seeds were separated by high performance liquid chromatography (HPLC). A HPLC system using a Develosil ODS-5 column and gradient elution system from 30% to 80% methanol was selected for separation and quantitative determination of sesaminol triglucoside, sesaminol diglucoside, and sesaminol monoglucoside. Quantitative analyses for these sesaminol glucosides, sesaminol triglucoside, sesaminol diglucoside, and sesaminol monoglucoside were determined on the basis of standard curve of sesaminol glucosides. Sesaminol triglucoside, sesaminol diglucoside and sesaminol monoglucoside contents of the seed of one Korean sesame cultivar, Danbaekggae, were 56.4 mg/100g, 9.6 mg/100g, and 7.5 mg/100g, respectively. The most abundant aglycon of lignan glucosides in sesame seed was sesaminol triglucoside
        9695.
        1998.09 KCI 등재 서비스 종료(열람 제한)
        Volatile components were extracted from leaves of two Boxthorn (Lycium chinense M.) cultivars by using simultaneous distillation and extraction, analyzed by gas chromatography-mass spectrometry. Seventy components were identified : 13 acids, 15 alcohols, 18 hydrocarbons, 13 carbonyls, three esters, three ionones, and five others. The principal volatile components (and their peak area percentage) were n-pentanol (11.2~30.2%), phytol (14.5~28.3%), hexadecanoic acid (13.5~17.1%) 2,3-dihydrobenzofuran (1.5~4.2%), benzyl alcohol (1.9-4.8%), phenylacetaldehyde (1.8~3.2%), and octadecadienoic acid (1.7~10.7%). Fresh leaves showed much higher peak area than that of dried leaf in n-pentanol, n-hexanol, cis-2-penten-l-ol, cis-3-hexen-l-ol, benzyl alcohol, and β -phenylethyl alcohol, while dried leaves showed much higher content than that of fresh leaves in 9-hydroxytheaspran A, octadecanoic acid and octadecadienic acid.
        9696.
        1998.09 KCI 등재 서비스 종료(열람 제한)
        The cyanidin 3-glucoside (C3G) extracted from pigmented rice seeds in 0.5% TFA (Trifluoro acetic acid) -95% ethanol was separated by High Performance Liquid Chromatography (HPLC). A HPLC system using a Develosil ODS-5 column and 0.1 % TFA-H2O ~0.1 % TFA-CH3CN gradient elution was selected for separation and quantitative determination of C3G. Regression equation obtained for the standard content of C3G pigment was as Y=21.95293* X-14.726771 (r=0.99** ). Using this method, 326 domestic and introduced collections were evaluated for the C3G content. The Korean bred cultivar 'Heugjinjubyeo', showed highest C3G content (552 mg/100g seed) among the tested cultivars. Among the pigmented rice cultivars ten cultivars were selected for containing a high content of C3G. The content of C3G per 100g seeds was in high order as follows: Heugjinjubyeo (552mg)>Cheng Chang (321mg)>Kilimgeugmi (240mg)>PI160979-2 (224mg)>Hong Shei Lo (221mg)>Heugnambyeo (191 mg)>Mitak =PIl60979-1 (186mg)>Suwon425 (163mg)>Sanghaehyanghyeolla (108mg). The C3G pigment was not detected in the common white rice cultivars.
        9697.
        1998.09 KCI 등재 서비스 종료(열람 제한)
        Sesaminol in sesame seed was postulated to have antitumor activity. The present study was performed to characterize the role of crude sesaminol extracted from sesame seed (Sesame Crude Sesaminol; SCS) on inhibiting the in vitro growth of human leukemia HL-60 cells. SCS inhibited the growth of human leukemia HL 60 cells in culture and macromolecular synthesis in a dose and time dependent manner. The cytostatic range of SCS concentration was found to be 60 to 100 ~mu~textrmg /ml. SCS concentration greater than 200 ~mu~textrmg /mlwere cytocidal to HL-60 cells. When SCS concentraction was 6 ~mu~textrmg /mland 50 ~mu~textrmg /ml the synthesis of HL-60 cells was inhibited by 35% for DNA, 6% for RNA and 5% for protein and 83% for DNA, 76% for RNA and 60% for protein. Of specific interest was the irreversible effect of SCS in inhibiting DNA synthesis of HL-60 cells. This was evidenced from the fact that, even after washed with PBS three times, preincubated HL-60 cells still showed the inhibited DNA synthesis.
        9698.
        1998.09 KCI 등재 서비스 종료(열람 제한)
        Diallel analysis was conducted with FI's derived from crossing in all combinations without reciprocals among six rice varieties; three tropical japonica and three temperate japonica varieties, with different traits associated with panicle and flag leaf. Epistasis was observed in the number of primary branches (PB) per panicle and of spikelets per panicle, while flag leaf length, flag leaf color, PB length and neck node thickness were explained with the additive-dominance model. The estimated genetic mode of flag leaf length and PB length was a positive complete dominance model with high heritability, and that of flag leaf color and neck node thickness was an incomplete dominance model. In particular, tropical japonica varieties with low-tillering and heavy-panicle appear to have higher number of dominant genes for flag leaf length and PB length than temperate japonica varieties.
        9700.
        1998.06 KCI 등재 서비스 종료(열람 제한)
        The characteristics of the basic statistics and steadiness of wind and the monthly normality test of surface wind distribution are investigated by using the observed wind data compiled from 10m meteorological observation tower at Seocheon district, where is located in the western coastal region of Korea, during the period from Feb. 7, 1996 to Feb. 7 1997. The northerly is appeared to be even in August and Sepember due to the influences of local circulation such as land and sea breeze. The correlation coefficients(γuv) between two wind components are seemed to be positive during the in the period of from June to September and negative from October to April, respectively. The constancy of wind is high in winter and low in summer. It is evident that the modal values of S decrease and their maximum values shifts to lower values with increasing sampling time. It is found from monthly normality test based on the skewness and the excess of kurtosis coefficients that the distribution of zonal wind component is normal in spring and meridional one is normal in late summer and early autumn.