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        검색결과 607

        501.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        There are many species as bioenergy crops and have different cold sensitivity in each. Cold-tolerant camelina and rapeseed, -sensitive jatropha, were used to investigate the cold stress response. Various physiological parameters such as leaf length, width, electrolyte leakage, stomatal conductance and chlorophyll fluorescence were measured to determine the growth rate treated with cold (2℃) for 5 days. Cold treated jatropha was damaged seriousiy but camelina and rapeseed were withstand. In order to investigate the cold-response on plasma membrane H+-ATPase activity isolated from leaves and roots of camelina, rapeseed and jatropha crops were exposed to cold stress. There were an increase in the activity of leaves and roots plasma membrane in cold-tolerant crops (camelina, rapeseed) while decreased the activity in cold-sensitive crop (jatropha). By western-blot analyses, the protein expression of plasma membrane H+-ATPase isolated from leaves and roots of camelina and rapeseed was increased in the presence of cold stress, but not in jatropha. These results may suggest that increased plasma membrane H+-ATPase of crops are closely related with cold-tolerant.
        505.
        2009.06 KCI 등재 서비스 종료(열람 제한)
        This research investigated the impact of the International Student Teacher Exchange Program (I-STEP) on the enhancement of preservice teachers’ cultural sensitivity. The results of this research are consistent to the findings from previous studies confirming the positive effect of international field experiences. Specifically, the analysis of the quantitative survey showed that the 2008 I-STEP programs were effective in improving participant impressions on the hosts’ ethno-groups. The journal analysis confirmed this result by showing that the preservice teachers reconsidered their beliefs about other ethnic groups through the program participation. Although the participants had possessed a set of biases about the ethnic groups, the participants interacted with host ethnic groups and reconsidered their beliefs about the groups. Through person-to-person interaction, the participants found that human beings share some commonalities in ways of feeling and living. At the same time, they realized that people can be different and that the differences are cultural constructions. As the I-STEP allowed the participants to access to others’ lived worlds, they witnessed other possibilities of being in the world and reflected upon their own ways of living. Thus, this experience of cultural emersion expanded the participants’ worldviews and developed the attitude of active respect. Based on these findings, this paper presents several implications for the future development of international field experience programs for preservice teachers and further of multicultural teacher education curricula in general.
        510.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Carrots (Daucus carota L.) are consumed as an important dietary source of b-carotene (provitamin A), a-carotene and lutein. An HPLC method was applied to determine the content of the carotenoid composition in carrot cultivars from Korea. Analyses were carried out with five carrot cultivars (Socheon-5-chon, Hongsim-5-chon, Myeongju-5-chon, Seonhongbom-5-chon and Betarich) sown at April, 2007 and six cultivars (Yeoreum-5-chon, Hanyeoreum-5-chon, Sinheukjeon-5-chon, Bibariheukjeon, Manina and Betarich) sown at August of the same year. The former and the latter carrots were harvested after 110 and 96 days from seeding, respectively, and the carotenoids were extracted with acetone after freeze-drying. The amount of a-carotenewas similar to that of b-carotene for the carrot cultivars sown at spring, while the content was about a half of b-carotene content for the latter cultivars. In addition, the average content of lutein in the former cultivars was nine times higher than that in the latter cultivars. Among the spring cultivation types, Socheon-5-chon and Myeongju-5-chon showed higher amount of a-carotene and b-carotene, while the higher amount was determined in Yeoreum-5-chon and Sinheukjeon-5-chon among the autumn cultivation types. This difference between spring cultivation types and autumn cultivation types was also shown in commercial two types of carrots purchased from local market.
        511.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        IL-34 (NIL) developed by introgressing chromosomal segment substitution from an accession of Oryza minuta (2n=48, BBCC, Acc. No. 101141) into the O. sativa subsp. japonica cv. Hwaseongbyeo, showed significantly higher number of spikelets per panicle (SSP) than the recurrent parent Hwaseongbyeo. QTL analysis in F2 generation derived from the cross between IL-34 and Hwaseongbyeo revealed that ssp7, a QTL was located in the pericentromeric region of chromosome 7. The frequency distribution of spikelets per panicle followed 3:1 ratio for single locus segregation. The additive effect of the O. minuta allele at the QTL was 23 spikelets per panicle, and 43.6% of the phenotypic variance could be explained by the segregation of marker RM21596. To clarify whether ssp7 could be dissected genetically, we carried out fine-scale mapping with 3,700 F2 plants derived from the cross between IL-34 and Hwaseongbyeo using markers flanking spp7. 186 F2 plants having informative recombination breakpoints within the region flanked by two SSR markers RM500 and RM21615 were identified and used for fine mapping of ssp7. ssp7 was mapped between the SSR markers RM21596 and RM418 which was approximately 441kb in length based on the physical map of the region. Of great interests, the QTL region also had effects on primary branch number (PB), grains per panicle (SP) and grain yield (YD). These results are very useful for transferring or pyramiding ssp7 by molecular marker assistant selection in rice breeding programs.
        512.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Grain weight (GW) or grain size is the most important target not only as a major component of grain yield, but also associated with the cooking quality in rice breeding program. In a previous study, two loci for grain weight, gw8 and gw9, have been fine map to about 306.4kb and 37.4kb, respectively, in backcross populations derived from a cross between the Korean japonica cultivar Hwaseongbyeo and Oryza rufipigon (IRGC 105491). Both O.rufipogon alleles increased GW in the Hwaseongbyeo background despite the fact that O. rufipogon was the small-seeded parent. To test the effect of pyramiding the QTLs for grain weight, an F2 population consisted of 226 individuals was developed derived from the cross between the two QTLs (gw8 and gw9), and used MAS to select nearly isgenic lines for two QTLs and a pyramiding line. Molecular genotyping of F2 population revealed the existence of interaction between gw8 and gw9. Moreover, the interaction was also confirmed by phenotypic analysis of four QTL-NILs. The results suggest that epistasis interaction is important genetic basis in determining yield traits in rice.
        513.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Cadmium (Cd) is one of heavy metals that can be easily absorbed by plant roots, and transported from soil to shoots. The effect of Cd concentration (0~200 μM) on the physiological responses, Cd content of shoot and root, and antioxidant enzymes by oil plants Jatropha curcas (cv. Biji Jarak) were investigated in hydroponics system for two weeks. Stomatal conductance was significantly depressed by Cd treated plants. However, the leaf chlorophyll content was unaffected by Cd treated plants. Cd contents in the roots of Jatropha were accumulated higher than those of shoots. Jatropha treated plants at 100 and 200 μM was found to accumulate more than 100 mg kg-1 of Cd in shoots. Jatropha plants had a high ablity to uptake Cd from soil and transport it from soil to shoot as a Cd hyperaccumulator plant because of plants accumulating more than 100 mg kg-1 of Cd in shoots are considered to define as Cd hyperaccumulator. These results confirm that Jatropha is a suitable candidate for the phytoremediation of high-level cadmium contaminated soils.
        514.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Brassica napus L. (Brassicaceae) plantation has increased as its seed is the primary source for bio-diesels. This study was conducted Male sterile (MS) line (cv. 'Sun-Mang') to pollen parent (cv. 'Mokpo 64') ratio of rape plants on fatty acid compositions of six sequential stages and yield performances. Ratio of MS line to pollen parent was followed, 4:2, 10:1, and 10:2, respectively. Seeds of six sequential stages (35, 40, 45, 50, 55, and 60 days after flowering) were collected and determined using SEED FAME ESTIMATION. The results showed that oleic acid content (C18:1) of the MS to pollen parent ratio (4:2) relatively increased up to 60 days after flowering compared to other ratios. Other fatty acid compositions such as palmitic acid (C16:0), stearic acid (C18:0), linoleic acid (C18:2) and linolenic acid (C18:3) contents decreased during seed maturation period. Seed weight (1000 seeds) of MS to pollen parent ratio (4:2) was higher than other treatments. These results suggest that fatty acid compositions and seed weight was affected by ratio of MS line to pollen parent. For rape seed production, a suitable ratio of MS line to pollen parent will be required to cultivate rape plantations.
        515.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Jatropha (Jatropha curcas L.) is a shrub or tree belonging the genus Euphorbiaceae and is cultivated in a tropical regions including South America, South-East Asia, India and Africa. Jatropha possibly is adapted to grow in a wide range of environments for producing non-edible oils. The objective of the study is to determine effect of salt and drought on plant growth characteristics. Treatments are thus followed, 100 and 200 mM NaCl and 5 and 10% PEG. Various physiological parameters such leaf length and width, stomatal conductance, chlorophyll fluorescence and gene expression were investigated. The results showed that from 2 days onwards, 100 and 200mM NaCl treatments were significantly suppressed leaf length, width, and stomatal conductance, but 5% and 10% PEG treatments showed a similar trend of control plants. Gene expression of JcACBP of the 100 mM NaCl was slightly decreased compred to those of other treatments. These results indicate that 100 and 200 mM NaCl treatments significantly showed negative response, but 5 and 10% PEG treatments improved plant growth and development of Jatropha.
        516.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to provide the fundamental data based on the agronomic, phsyco-chemical characteristics, and quntification of volatile compounds of aroma rice germplasms. Among the 104 rice germplasm, five accessions of domestic aroma rice, 14 accessions of widely cultivated rice, and 60 accessions of foreign aroma rice were selected with excellent agronomic traits, high fertility and germination rate. The average amylose content of foreign aroma rice was higher than domestic aroma rice and widely cultured domestic rice. The domestic aroma rice was shown low protein and the foreign Indica types of aroma rice exhibited a wide range of protein contents. The foreign aroma rice were distributed a variable range of ADV value and lower than the both domestic aroma rice and widely cultured domestic rice. And it shown the difference aspect of amylograms according to the eco-type of the domestic and foreign aroma and the general rice, and it was distinguishable in difference of the aspect of the endosperm of rice as non-glutinous rice, waxy rice, and middle-waxy rice. The optimal extraction conditions of 2-Actyl-1- Pyrroline is recommended that five second grinding time, using 100 % ethyl alcohol, at 90℃ for 30 minutes. The domestic and the foreign aroma rice has more than mild aroma grade. A total 30 accession of aroma rice germplasm selected based on their 2AP concentration, aroma grade and agronomic traits. A total of 158 volatile and semi-volatile compounds were identified from 30 accessions of aroma rice germplasm, including 32 alcohols, 25 acids, 25 ketones, 21 hydrocarbon, 18 esters, 16 aldehydes, 4 ethers, 5 amines, 2 phenols, 2 bases, and 8 miscellaneous compounds. The thirty aroma rice germplasms could be classified into five groups according to the major odor or aroma compounds.
        517.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to identify the quantitative trait loci (QTLs) for traits related to cold tolerance using an introgression lines (ILs) derived from a cross between a japonica weedy rice and a Tongil-type rice. Among the 80 RILs, one line (CR1835) showing tolerance for cold tolerance related to traits such as panicle exsertion and discoloration in the cold water plot was selected and backcrossed to the recurrent parent, Milyang 23. This line possessed Hapcheonaengmi 3 segments on chromosomes 1, 5 and 11. By two backcrosses to Milyang 23 and selfing, a total of 88 BC3F5 progenies were developed. The 88 ILs were evaluated for traits related to agricultural performance in cold water and in control plots. Cold tolerance was measured as difference of the culm length, spikelet fertility between two plots and panicle exsertion in cold water plot. The 88 ILs showed decreased culm length and increased anthocyan content in cold water plot than in the control water plot.
        518.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Awn, one of the domestication-related traits in rice might play an important role in seed dispersal. In a previous study, one major QTL, awn8 was detected on chromosome 8 using 120 RILs and 62 ILs derived from a cross between Hwayeongbyeo and O. rufipogon Griff. (Acc. W1944). We developed 140 BC1F3, 341 BC1F4 and 1533 BC1F5 plants from selfing of one plant selected from former generation. Each of selected plant was Hwayeongbeyo/W1944 heterozygous in the target region of chromosome 8. The Target marker(RM256) significantly linked to awn8 explained 60.3% of the total phenotypic variance in BC1F4 generations and the W1944 allele increased awn length. Using several substitution mapping, The awn8 QTL could be narrow down to the interval between RM23338-RM5485, with a distance of about 85.29kb. Total of ten genes were predicted in this region. At the same time, 34 BC3F5 lines were developed as the diverse NILs on chromosme 8. Using these NILs, One QTL for primary branch was detected in the target region and W1944 allele increased branch number. Characterization of the awn8 QTL would contribute the understanding of rice domestication and evolution and additional experiment would be need to be clarified whether awn8 and pb8 was due to linkage drag of independent genes or pleiotropic effect of the same gene.
        519.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Brassica napus L. (Brassicaceae), is one of major oilseed crops commonly cultivated cereal-growing areas after the rice harvest in Asia countries, has recently focused much attention as its seed is the primary source for bio-diesels. In rapeseed growing regions of South Korea, typical double-cropping regions are constantly or periodically received with poorly drained soil condition or encountered dried soil condition during the reproductive stage. This study was conducted on rapeseed plants subjected to both waterlogging and drought conditions for 4 days to investigate responses in physiological characteristics, fatty acid compositions and yield performances at reproductive stage. The treatments were thus as follows: (1) control normally irrigated, (2) waterlogging treatment were flooded by placing their pots inside larger plastic pots filled with tap water with a 2-cm water layer over soil surface, (3) drought treatment was not irrigated. For recovery period, rapeseed plants subjected to waterlogging for 4 days were drained after waterlogging, and irrigated daily as control. Drought treatment after recovery period was irrigated daily as control. Rate of photosynthesis and stomatal conductance of waterlogging and drought treated plants significantly decreased within 4 days. For recovery period, stomatal conductance and photosynthetic rate of the waterlogged and drought treated plants occurred level similar to that of the controls by 2 days after recovery period. Fatty acid compositions of the both waterlogging and drought treated plants did not affect, but yield performances of the waterlogging treatment significantly decreased. These results suggest that both waterlogging and drought conditions for 4 days did not influence fatty acid compositions, but affected yield performance at final harvest.
        520.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        AtHMA3 is one of P1B-ATPase of Arabidopsis thaliana which transports and/or stores Cd and Pb in the plant cell. To test whether AtHMA3 can be used to develop enhanced resistance plant to Cd and Pb for phytoremediation, we overexpressed AtHMA3 in Columbia-0 using a pBI121vector containing the 35S promoter. To evaluate their Cd and Pb resistance, seeds of three different T3 homozygous(HMA3-1~3) and wild type plants(col-0) were germinated and grown on agar plates containing 50μM Cd, 500μM Pb and 50μM Cd+ 500μM Pb for 3 weeks. 35S::AtHMA3 grew better than wild type plants about 1.1-to 1.8-fold in Cd or Pb containg mediums. Fresh weights of all three lines of transgenic plants were 1.2-to 1.5-fold higher than those of wild type plants in Cd or Pb-containing medium. In addition to, we measured Cd and Pb content in both wild type and transgenic plants grown in solution with 50μM Cd, 500μM Pb and 50μM Cd+ 500μM Pb for 6 d. AtHMA3-overexpressing plants had consistently higher Cd and Pb contents than wild type plants. Chlorophyll contents were not significant difference between overlines and wild-types. These results show that HMA3 contributes to Cd and Pb resistance, and it might be useful for the phytoremediation.