• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.449-454
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• 2011

This experiment was conducted to evaluate growth rate among 15 embryogenic tissue lines (ETLs), comparison of maturation on somatic embryos (SEs) with 13 ETLs and efficiency with various concentrations of gelrite on SEs germination in Japanese red pine (Pinus densiflora). In comparison of ETLs growth rate (folds) with 15 lines, the 05-4 line (5.3 folds) showed the highest rate, on the other hand, the lowest one was recorded in the line of 05-37 (1.4 folds). The 13 ETLs were tested for the extent of SEs production. The best production was recorded in the line of 05-4 (39.8/90 mg F.W.). However, most of ETLs, except 5 lines (05-4, 12, 21, 29 and 37), did not produce SEs at all, therefore, big differences in the ability of SEs production existed among the ETLs tested. Effects of various gelrite concentrations for SEs germination with 3 ETLs were also compared. The highest result was obtained from 0.2% gelrite concentration with 05-4 line (47.3%), there was a inclination that the rate of germination was gradually declined over 0.2% gelrite concentration with the 05-4 and 29 lines. respectively. In contrast, in the line of 05-37, no SEs germination occurred on medium with 0.1 or 0.2% gelrite. In conclusion, the growth rate, SEs production and germination frequency were appeared to deeply depended on the ETLs.

• Ecology and Resilient Infrastructure
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• v.9 no.2
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• pp.83-92
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• 2022

The 2020 summer extreme flood severely disturbed the riparian ecosystem of the Seomjin River. Some trees were killed by the flood impact, whereas others have recovered through epicormic regeneration after the disturbance. At the same time, several tree individuals newly germinated. This research aimed to explain the recovery of the riparian ecosystem by spatial proximity between each tree individual of different characteristics, such as "dead", "recovered", and "newly germinated". A spatial point pattern analysis based on K and g-functions revealed that the newly germinated trees and the existing trees were distributed in the spatially clumping patterns. However, further detailed analysis revealed that the new trees were statistically less attracted to the recovered trees than the dead trees, implying competitive interactions hidden in the facilitative interactions. Habitat amelioration by the existing trees positively affected the growth of the new trees, while "living" existing trees were competing with the new trees for resources. This research is expected to provide new knowledge in this era of rapid climate change, which likely induces stronger and more frequent natural disturbance than before. Environmental factors have been widely used for ecosystem modeling, but species interactions, represented by the relative spatial distribution of plant individuals, are also valuable factors explaining ecosystem dynamics.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.291-307
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• 2016

Evaluation of the extinction risk of endangered plants at international, national as well as at regional levels is essential to the implementation of plans for direct conservation activities. Reports indicate that 34 endangered plants are distributed in the middle eastern area of Korea. For each endangered plant, we investigated the sites, area of extents, population size, and factors that affect population extinction. We assessed risk factors based on 10 evaluation criteria including the results from the investigation and the life traits each endangered plant has. As a result of evaluating the risk factors, these 34 endangered plants are classified into 3 groups: the first category comprises 12 endangered plants that require active and urgent conservation of habitats due to multiple risk factors; the second group has 16 endangered plants that should be able to persist with the removal of a few direct risk factors; the third category has 6 endangered plants that can persist with minimal management due to comparatively large distributed area and numerous individuals. It was found that most major risk factors in the population of endangered plants are caused by disruption of habitats and population extinction due to the increase of human habitation in the concerned areas, development and illegal harvesting. Futhermore, ecological collapse from decreasing habitats and malfunctioning mechanism of extinction and regeneration due to the changes of vegetational environment can be the other causes. From the area of the present investigations, we selected 5 regions according to the number of species and the frequency of appearance and importance of conservation measures. Also, we suggested a conservation strategy according to the regional characteristics. We suggest that the method for evaluating extinction risk of endangered plants includes distributional data and life traits of species. In addition, we underscore the necessity for understanding population dynamics and ecological niche of the each target species.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.401-408
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• 2017

Herein, we report the meristem-tip culture from dormant buds of grape 'Kyoho' single-infected with Grapevine fleck virus (GFkV), which is phloem-limited and transmitted by graft inoculation. We produced GFkV-free shoots without thermo- or chemotherapy using meristem-tip explants approximately 0.3 mm (73 explants) and 0.8 mm long (five explants) including shoot apical meristem, 2-5 leaf primordia, and 1-4 uncommitted primordia from dormant buds of the infected woody cuttings (stored at $4^{\circ}C$). Explants were cultured on Murashige and Skoog (MS) medium supplemented with 3% sucrose, 3.0 mg/L benzyladenine (BA) and 0.1 mg/L indole-3-butyric acid (IBA). After 16 weeks of culture, shoot (10-mm long) regeneration frequency achieved from 0.3-mm explants was 4.1% and that obtained from 0.8-mm explants was 40.0%. Virus-free efficiency (expressed as the percentage of RT-PCR negative shoots regenerated) from 0.3- and 0.8-mm explants was 100% and 50%, respectively. Following in vitro multiplication, RT-PCR assays revealed identical results to assays of the first regenerated shoots. Our new methodological approach could be applied for eliminating other viruses in grapevines, as well as for producing virus-free plants in many other deciduous tree species, including fruit trees.

• Korean journal of applied entomology
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• v.54 no.1
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• pp.7-15
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• 2015

CpBV (Cotesia plutellae bracovirus) is a polydnavirus and encodes a cystatin (CpBV-CST1) gene. Its overexpression suppresses insect immunity and alters insect developmental processes. This study aimed to construct a genetically modified (GM) tobacco to further explore the physiological function of the viral cystatin and to apply to control insect pests. To this end, the transgenic tobacco lines were screened in expression of the target gene and assessed in insecticidal activity. A recombinant vector (pBI121-CST) was prepared and used to transform a bacterium, Agrobacterium tumefasciens. The transformed bacteria were used to generate transgenic tobacco lines, which were induced to grow callus and resulted in about 92% of shoot regeneration. The regenerated plants were screened by PCR analysis to confirm the insertion of the target gene in the plant genome. In addition, the expression of the target gene was assessed in the regenerated plants by quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis showed that the transgenic line plant expressed the target gene about 17 times more than the control tobacco, indicating a stable insertion and expression of the target gene in the transgenic tobacco line. The insecticidal activity was then analyzed using the screened transgenic tobacco lines against the teneral 1st instar larvae of the oriental tobacco budworm, Helicoverpa assulta. Though there was a variation in the insecticidal efficacy among transgenic lines, T9 and T12 lines exhibited more than 95% mortality at 7 days after feeding treatment. These results suggest that CpBV-CST1 is a useful genetic resource to be used to generate GM crop against insect pests.

• Journal of Plant Biotechnology
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• v.49 no.1
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• pp.74-81
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• 2022

Brassica napus, an oil crop that produces rapeseed oil, is an allotetraploid (AACC, 2n = 38) produced by natural hybridization between B. rapa and B. oleracea. In this study, microspore was cultured using the F₁ developed from a cross between 'EMS26' line with high oleic acid content and 'J8634-B-30' lines. The flower bud size showing the nuclear development at the late uninucleate and binucleate stage with high embryogenesis rate was 2.6 ~ 3.5 mm. Microspores were cultured using only this size and after then most microspore embryo developed into secondary embryos and then regeneration plants obtained from the developed multilobe. The analysis of the ploidy of the plants revealed that 66.7% and 27.8% of the total lines were tetraploids and octoploids, respectively. The sizes of stomatal cells in tetraploids, octoploids, and diploids were 25.5, 35.6, and 19.9 ㎛, respectively, indicating that ploidy level was positively correlated with cell size. Furthermore, 62 tetraploid doubled haploid (DH) lines were selected. The average oleic acid (C18:1) and linolenic acid (C18:3) concentrations of DH were 72.3% and 6.2%, respectively. Oleic acid and linolenic acid concentrations exceeded the two parental values in 5 and 14 DH lines, respectively, suggesting that these two fatty acids had transgressive segregation. Therefore, the DH population can be utilized for the biosynthesis of unsaturated fatty acids in rapeseed and related genes. It can also be used as a breeding material for varieties with high oleic acid concentrations.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.1
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• pp.93-106
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• 2014

In this study, Analyze environment of location, investigation into vegetation resources, survey management status and establish to classify the management area for Natural monument No.374 Pyengdae-ri Torreya nucifera forest. The results were as follows: First, Torreya nucifera forest is concerned about influence of development caused by utilization of land changes to agricultural region. Thus, establish to preservation management plan for preservation of prototypical and should be excluded development activity to cause the change of terrain that Gotjawal in the Torreya nucifera forest is factor of base for generating species diversity. Secondly, Torreya nucifera forest summarized as 402 taxa composed 91 familly 263 genus, 353 species, 41 varieties and 8 forms. The distribution of plants for the first grade & second grade appear of endangered plant to Ministry of Environment specify. But, critically endangered in forest by changes in habitat, diseases and illegal overcatching. Therefore, when establishing forest management plan should be considered for put priority on protection. Thirdly, Torreya nucifera representing the upper layer of the vegetation structure. But, old tree oriented management and conservation strategy result in poor age structure. Furthermore, desiccation of forest on artificial management and decline in Torreya nucifera habitat on ecological succession can indicate a problem in forest. Therefore, establish plan such as regulation of population density and sapling tree proliferation for sustainable characteristics of the Torreya nucifera forest. Fourth, Appear to damaged of trails caused by use. Especially, Scoria way occurs a lot of damaged and higher than the share ratio of each section. Therefore, share ratio reduction Plan should be considered through the additional development of tourism routes rather than the replacement of Scoria. Fifth, Representing high preference of the Torreya nucifera forest tourist factor confirmed the plant elements. It is sensitive to usage pressure. And requires continuous monitoring by characteristic of Non-permanent. In addition, need an additional plan such as additional development of tourism elements and active utilizing an element of high preference. Sixth, Strength of protected should be differently accordance with importance. First grade area have to maintenance of plant population and natural habitats. Set the direction of the management. Second grade areas focus on annual regeneration of the forest. Third grade area should be utilized demonstration forest or set to the area for proliferate sapling. Fourth grade areas require the introduced of partial rest system that disturbance are often found in proper vegetation. Fifth grade area appropriate to the service area for promoting tourism by utilizing natural resources in Torreya nucifera forest. Furthermore, installation of a buffer zone in relatively low ratings area and periodic monitoring to the improvement of edge effect that adjacent areas of different class.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.222-230
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• 1983

This study was designed to develop a process for the immobilization of xylose isomerase(D-xylose ketol isomerase, EC 5.3.1.5) from Streptomyces griseolus previously isolated by the authors and its application on a pilot plant scale for the production of high fructose corn syrup. The biomass which has endo-excreted xylose isomerase was homogenized under a pressure of $500kg/cm^2$ and 90.8% of the enzyme recovery of the native activity was obtained as compared to 54.7% recovery by the lysozyme treatment. Ionic bonding method was adopted for the enzyme immobilization due to its many reported merits. It was found that the porous resins such as Diaion HP 20, Duolite A-7, Amberlite IRA 93 and 94 were effective in immobilizing the enzyme. In addition, it was disclosed that the regeneration form of $BO_4--$ is effective for Amberlite IRA 93 and $HCO_3-$ for Diaion HP 20. Optimal immobilization condition for Amberlite IRA 93 was pH 8.0 and $55^{\circ}C$ yielding 80.6% of immobilization. Activity decay test showed half life of the immobilized enzyme with Amberlite IRA 93 was more than 24 days at $65^{\circ}C$. The carrier was evaluated to be resuable and its result showed the relative immobilization yields were 98.2, 93.3, 90.7 and 87.5%, respectively at second, third, forth and fifth rebinding test of the enzyme on Amberlite IRA 93. Optimal temperature of the immobilized enzyme was slightly lowered and the range widened to $60\sim70^{\circ}C$, while optimal pH moved toward $8.0\sim8.3$ in its isomerization reaction. The trial production result of high fructose corn syrup in pilot scale immobilization showed that one liter of immobilized xylose isomerase (350 IXIU/ml-R) is capable producing about 293l high fructose corn syrup(75% dry substance) in 30 days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.757-767
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• 1995

This experiment was done to determine the optimum concentration of IAA for root development in plants regenerated from the callus culture of barley embryos. Two concentrations of 2,4-D, 3ppm and 5ppm selected as an optimum among five different concentrations in the previous experiment were used for callus induction and proliferation in this experiment. For callus induction, 3ppm of 2,4-D produced 35.6% in immature embryos and 4.4% in mature embryos, while 5ppm gave 33.8% in immature and 5.6% in mature embryos. Out of 320 immature embryos cultured, 111 embryos were induced to calli and 684 plants were produced from them, while only 16 embryos were induced to calli from 320 mature embryos and 92 plants were restored. The rates of callusing and plant regeneration were 34.7%, 214% in immature embryos and 5.0%, 28.7% in mature embryos, respectively. The average root lengths and root numbers of plants restored from callus at five different IAA concentrations of 0ppm, Ippm, 5ppm, l0ppm and 30ppm were 7.9mm, 3.6; 18.4mm, 5.2; 16.1mm, 3.9; 8.5mm, 3.5 and 6.4mm, 3.4, while plants directly obtained from mature embryos were 14.8mm, 4.9; 4.9mm, 3.6; 4.3mm, 3.1; 3.6mm, 2.6 and 3.2mm, 2.1, respectively. Therefore, 1ppm gave the best result for the root. promotion in callus, whle 0ppm, a control, gave the largest root developmemt in embryos. High concentration of lAA(30ppm) in callus and any exogeneous supplement of lAA in embryos negatively affected to the root lengths and root numbers. Genotypic effect was also observed in given four varieties, Bruce, Klages, Olbori and Albori. For chromosome doubling, when 0.1% colchicine was applied on 428 plants under three different conditions such as air circulation, temperatures and growth stages, 319 plants of doubled haploids were obtained so that the rate was 74.5%

• Korean Journal of Medicinal Crop Science
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• v.9 no.4
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• pp.310-317
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• 2001

The regenerated-bulblets placed in liquid free media resulted in good formation of roots and bulblets. On 1/4 MS free medium, roots and bulblets were predominantly induced. The 1/4 MS liquid medium supplemented with plant growth regulators was the best suitable condition for elongation of leaves and roots. Somatic embryos were frequently developed from embryogenic callus in liquid media with 2,4-D 1mg/ l . On free liquid media, the viability of callus reduced. As the salt strength of MS media reduces, the viability of callus reduced significantly. However, Leaves were induced from several callus clumps. When leaves, roots and bulb-scale segments were placed on MS media containing NAA 1mg/ l or 2,4-D 1mg/ l and various sucrose concentration, the best result about the differentiation, growth of leaf and the differentiation of leaf was obtained on MS media added 1.5% sucrose and 2,4-D 1mg/ l, 3% sucrose and NAA 1mg/ l, and 1.5% sucrose and NAA 1mg/ l, respectively. Also the better result differentiation, growth of root and differentiation of bulb was obtained on MS media with 6% sucrose and NAA 1mg/ l. Spermidine promoted the growth of leaf and the differentiation of bulb. However, spermine promoted the differentiation of leaf, the differentiation and the growth of root in MS solid media. On the MS liquid media, both spermine and spermidine stimulated organogenesis from bulb-scale segments. Regenerated plantlets were acclimatizated and grown in greenhouse in vermiculite + perlite (1 : 1 by volume) well. The optimal soil condition of rooting for plantlets regenerated was in peat moss.