• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.300-307
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• 2006

To clarify the morphological and geographical differentiation among the polyploid complexes of L. lancifolium collections in Korea, the mo게hological variation of 173 accessions were analyzed by ANOVA (one-way analysis of variance) and PCA (principal component analysis) on the basis of 38 morphological characters. 173m accessions were grouped into 78 diploids and 95 triploids by ploid levels and the triploids separated into 75 inland triploids (all around the Korea) and 20 island triploids (Backryung-do and Sochung-do, westemmost and northernmost islands of Korea) by geographic distribution and morphology. Island triploids showed significant morphological differences with inland triploids in ANOVA by many floral and leaf characters. In PCAs, diploids were separated from inland triploids by having longer plant height, smaller flower characters, higher pollen fertility and more stomata. The first four principal components accounted for 44.1% of the total variation. Plots of the island and inland groups for the first and second principal components separated each other with slight overlapping. Although the ploid forms are different between diploid and island triploid, island triploids were more closely overlapped with diploids by principal component 1 and 2 than inland triploids. This reflects that the whole external morphology of island triploids are similar to that of diploids. This, the phenotypic differentiation between inland and island triploids seems to be partly related to their geographical origins.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.227-234
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• 2012

Recently, the population of toxic and/or unusable jellyfish is increasing during summer along the east coast of Korea, causing massive economical and ecological damage to fisheries, nuclear power plant and marine environment. To solve this problem, this study was carried out using jellyfish as a potential soil additive for horticulture. The jellyfish was solidified and homogenized, then mixed with a commercial bed soil. Allium tuberosum ROTH was planted to control bed soil (BS) and jellyfish powder mixed bed soil groups (Mixed bed soil, MBS), and following parameters were measured during five weeks: water content, electrical conductivity and growth of leaves. At the end of the experiment, bacterial community structures of each pot were analyzed by DGGE. The relative water adsorption of jellyfish powder was about 2.5 times greater compared to its dry weight. The water content of MBS group was significantly higher than BS group 6.5 to 14.2%, and the electric conductivity of MBS group was measured around 2.8 dS/m where BS group was resulted average of 1.8 dS/m. However, the leaves of BS group were grown 30% longer compared to MBS group. DGGE analysis of MBS group was shown in high number of phylum Bacteroidetes and increased diversity of Sphingobacteriia compared to BS group. Jellyfish powder as a soil additive surely will be a good candidate as humectant and microbiota stimulator, although there are several obstacles such as high electrical conductivity and residual alum salt which used for solidification of jellyfish.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.267-273
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• 2014

This study is to compare drought-resistance and to find the permanent wilting coefficient of Syringa Dilatata, Euonymus Japonica, Ligustrum Obtusifolium, Nandina Domestica, which are commonly used for rooftop garden due to their relatively strong drought resistance To compare the drought resistance precipitation was blocked from June 4, 2013 to July 20, 2013. During this time, the relative water content, specific electrical conductance, and water potential were measured every seven days and permanent wilting coefficients were investigated. Two days after precipitation was blocked, the relative water content in leaves were measured as follows: Ligustrum Obtusifolium 91.3%, Syringa Dilatata 92.9%, Nandina Domestica 91.2%, and Euonymus Japonica 90.1% respectively. After 28 days, relative water contents of leaves were reduced greatly 60.2% for Ligustrum Obtusifolium and 67.8% for Syringa Dilatata, but Nandina Domestica and Euonymus Japonica's reduced to 80.1% and 81.7% respectively. Permanent wilting coefficient was Ligustrum Obtusifolium 3.1%, Syringa Dilatata 2.1%, Nandina Domestica 1.6% and Euonymus Japonica 0.7%. In other words, the above four tree species are strong in drought resistance and Euonymus Japonica's drought resistance is the strongest while Nandina Domestica, Syringa Dilatata, Ligustrum Obtusifolium follow in that order.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.309-314
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• 2016

A locally adapted plant population under harsh environmental changes might survive for a long generation through maintaining proper level of genetic diversity. When it happens losing the genetic diversity too much fast, the population could be declining and probably become extinct. An isolated small population of Populus davidiana was investigated to study out the genetic diversity and the fine-scale spatial genetic structure. The estimated number of adult trees in the population of Mt. Worak, South Korea, was 350 in the total area of $14,000m^2$. The number of adults in a study plot ($70m{\times}70m$) was 123. The average age was 16-year-old and a 32-year-old tree was the oldest. The distribution of individuals was slightly aggregated in the plot. Sixty-one among the 123 individuals were randomly sampled to estimate genetic variation using AFLP markers. One hundred fifty-one (77%) of total 196 amplicons were polymorphic from six AFLP primer combinations. The average number of loci per primer combination was 32.7 (S.D.=7.2). Expected heterozygosity ($H_e$) and Shannon's diversity index (S.I.) were 0.154 and 0.254, respectively. These values were extremely lower than those of other P. davidiana populations in South Korea. Genetic patchiness was showed within 21 meters by spatial autocorrelation analysis and the isolated small size of population might be mainly attributed to the formation of such small patch size.

• Horticultural Science & Technology
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• v.17 no.4
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• pp.473-475
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• 1999

This study was carried out to restore the fertility by suppression of male sterility-induced gene using an antisense construct. Tobacco (cv. Petit Havana SR1) was transformed with the binary vector containing a GBAN215-6 promoter, an antisense diphtheria toxin (DTx-A) gene (pKDA215b) and a hygromycin resistant gene. Seventy-six confirmed transgenic plants regenerated from leaf disks were designated as the $R_0$ generation and selfed to produce the $R_1$ generation. From the inheritance study, five $R_1$ lines with multiple copies of the antisense construct were selected and selfed to identify homozygosity for the antisense construct. In order to restore fertility and finally to select restore lines, five $R_2$ lines with multiple copies of the antisense construct were crossed with male sterile plants. From these crosses, three different phenotypes have been observed: completely restored, partially restored, and not restored pollens, and otherwise tobacco plants were phenotypically same as normal plants. These plants were scored for the degree of restoration and selected for further study.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.270-274
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• 2013

The bumblebee, Bombus terrestris, has played an important role as one of the alternative pollinators since the outbreak of honeybee collapse disorder. Recently, pathogens and parasites such as viruses, bacteria and mites, which affect the life span and fecundity of their host, have been discovered in B. terristris. In order to detect the microsporidian pathogen, Nosema spp. in the field populations of B. terristris, we collected adults and isolated their genomic DNA for diagnostic PCR. The PCR primers specific for Nosema spp. were newly designed and applied to gene amplification for cloning. Only small subunit ribosomal RNA (SSU rRNA) gene of N. ceranae was successfully amplified among examined genes and sequenced, which indicates that N. ceranae mainly infects the examined field population of B. terristris. To detect of SSU rRNA gene, two regions of SSU rRNA gene were selected by primary PCR analysis and further analyzed in quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis demonstrated that SSU rRNA of N. ceranae was detected at concentration as low as $0.85ng/{\mu}l$ genomic DNA. This result suggests that the detection via qRT-PCR can be applied for the rapid and sensitive diagnosis of N. ceranae infection in the field population as well as risk assessment of B. terristris.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.56-61
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• 2005

Highly durable photocatalytic paper containing anatase $TiO_{2}$, active carbon and ceramic fiber, which can adsorb VOCs and decompose them by photo oxidation simultaneously, was manufactured and characterized. Optimum concentration of PDADMAC to let $TiO_{2}$ adhere on the surfaces of active carbon and ceramic fiber selectively was $10\~15$ ppm in a slurry mixture for making photocatalytic paper. The thickness and basis weight of the produced catalytic paper by paper-making method were 0.4 mm and 380 $g/m^{2}$, respectively. Adsorption reaction by active carbon and photocatalytic decomposition reaction by $TiO_{2}$ were proceeded simultaneously, by which the abatement rate was found to be greatly enhanced compared to the similar environment with single adsorption reaction or single photocatalytic reaction only. The selective attachment of $TiO_{2}$ on ceramic fiber and active carbon was found to be very effective in preventing decomposition of substrate by the $TiO_{2}$ attack during exposure to UV light.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.489-494
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• 1993

The amount of maize being imported from other countries to meet the national demand are increasing every year. Regardless of the usage whether it is for silage or for human consumption, amount of seeds for farmers are ever being increased. In order to solve the problems arising from the seed import, a program for developing waxy hybrids with high quality was set up at the College of Agr., Chungnam National University. The main breeding targets for high quality waxy hybrids are focused on the pericarp thickness. In order to obtain basic information needed for developing hybrids with thin pericarp, six inbred lines all derived from open pollinated Korean waxy lines were diallel crossed. Results obtained indicate that waxy hybrids with thin pericarp can be developed by choosing proper parental lines. Of the six inbreds, Jewon inbred had utmost thin pericarp compared with other lines. Hybrids crossed with Jewon showed also thinner pericarp than other hybrids. However, Danyang which has thick pericarp showed thicker pericarp in hybrid combinations. Variance due to general combining abilities was greater than the variance due to the specific combining abilities, indicating that additive gene effects are more important. The pericarp thickness of waxy hybrid endosperm varied with the parts of pericarp. The germinal side of the pericarp is comparatively thinner than the abgerminal side. The upper part (crown) has thicker pericaip than lower part (tip) of the kernel.

• The Korean Journal of Ecology
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• v.17 no.1
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• pp.23-35
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• 1994

To investigate phytotoxic substances in Artemisia argyi, the donor plant, and their biological activities, seed germination and seedling growth of receptor plants such as Arundinella hirta, Echinochloa crus-galli, Rumex crispus and Lactuca sativa were examined at different concentrations of aqueous extracts of the donor plant. Germination of four receptor species was inhibited by the extracts, while seedling growth was decreased to a lesser degree than in the germintion test. Germination, seedling growth and dry weight growth of Achyranthes japonica grown in pot were proportionally inhibited by the extracts. Volatile substances emitted from A, argi plant caused slight inhibition in the germination and seedling growth of the receptor species. Essential oil of the plant extracted by Karlsruker's apparatus inhibited growth of microorganisms and callus growth of Pinellia ternata and Oryza sativa. The GC /MS method was employed for analysis and identification of allelochemicals from A. argyi leaves. Sixty-one chemical substances such as a-pinene, camphene, 1. 8-cineol, etc. were identified from essential oil of A. argyi. The results of this experiment on seed germination, seedling growth, microorganism culture and tissue culture indicated that naturally occurring chemical substances from A. argyi would be responsible for the growth inhibition of plants studied.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.83-92
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• 2019

This study aims to examine at the garden characteristics of salt merchant in Yangzhou, China during the Ming and Qing Dynasties, I looked at the background of garden formation through the literature. In addition, analyzed the garden design method and components of salt merchants. The results were as follows; First, the Yangzhou area in the past has achieved cultural and economic development with the establishment of the ancient Grand Canal. Salt merchants accumulated wealth through trade, and created many gardens under the background of securing materials for create garden through trade, forming political forces through the cultivation of students, and inflow of foreign cultures. Second, salt merchants in Yangzhou asked garden experts to design and create the garden as a place for exchange and relaxation. Also, through the production of landscape changes using Gasan(假山) and a long corridor(長廊), clear classification of spaces using architectural elements, and the placement of buildings in scenic areas adjacent to the water, the gardens with practical and aesthetic functions were owned. Third, the gardens of Yangzhou Salt Merchants have a building-oriented commercial space on the front, and a garden-centered design characteristic on the back. The garden of the commercial zone was built in a simple form using pots, oddly shaped stone, bamboo and fence patterns in the remained space, focusing on the front of the building. The garden at the back formed a curved waterway connected to the canal is refracted across the garden. The garden also features piled stones(疊石), stone bridges and ship-shaped stone building(石舫). In addition, the design reflected the introduction of trees that take into account the climate and color contrast of Yangzhou province, pavement of various materials and patterns.