• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.353-359
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• 1988

Variations in photosynthetic capacities of leaves differing in thickness were explained on the basis of relationships between gas exchange and internal leaf structure. The relative importance of gas diffusion and of biochemical processes as limiting for leaf photosynthesis was also determined. Mesophyll cell surface was considered to be the limiting internal site for gas diffusion. and cell volume to be indicative of the sink capacity for CO$_2$ fixation. Increases in cell surface area were assumed to reduce proportionately mesophyll resistance to the liquid phase diffusion of CO$_2$. Increased cell volume was thought to account for a proportional increase in reaction rates for carboxylation, oxygenation. and dark respiration. This assumption was tested using chamber-grown Glycine max (L.) Merr. cv. Amsoy plants. Plants were grown under 200, 400, and 600 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR to induce development of various leaf thickness. Photosynthetic CO$_2$ uptake rates were measured on the 3rd and 4th trifoliolate leaves under 1000 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR and at the air temperature of 28 C. A pseudo -mechanistic photosynthesis model was modified to accommodate the concept of cell surface area as well as both cell volume and surface area. Both versions were used to simulate leaf photosynthesis. Computations based on volume and surface area showed slightly better agreement with experimental data than did those based on the surface area only. This implies that any single factor, whether it is photosynthetic model utilized in this study was suitable for relating leaf thickness to leaf productivity.

• Korean Journal of Medicinal Crop Science
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• v.23 no.1
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• pp.13-19
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• 2015

This study was conducted to improve the postharvest storage techniques of managing and storing seeds, to test qualities and viabilities of the seeds and to examine the germination rate and the protein expression of Achyranthes japonica Nakai. The seeds collected from different areas of Je-Cheon and Gwang-Ju were stored with different temperatures and durations. Two plant growth regulators and two seed priming were treated to investigate their effect on the germination rates and the days required for germination. The weight of one hundred seed collected in Gwang-Ju was heavier than those in Je-Cheon. Seed length collected in Gwang-Ju was also longer about 5.12 mm than those in Je-Cheon about 4.90 mm and seed width was longer in Gwang-Ju than those in Je-Cheon. The rates of seed germination in two different collection areas were higher about 2.9 to 13.0% in Gwang-Ju compared to those in Je-Cheon. Comparing its rates with the storing temperatures and durations, they were not clearly different in between $4^{\circ}C$ and $25^{\circ}C$ and they also were gradually decreased with getting longer storing durations. The germination rates treated by plant growth regulators were higher with $GA_3$ than those with Kinetin. The highest seed germination rate was appeared at 50 ppm of $GA_3$. Comparing its rates with different seed priming, they were relatively higher with $KNO_3$ than those with PEG6000. In protein expression patterns between before the germinating and after the germinating of seeds, more and clear bands were appeared in the seed after the germination compared to those before the germination of seeds, especially 10 ~ 20 kDa. These results showing more and clear bands were more clearly appeared in Gwang-Ju compared to Je-Cheon. Comparing the protein expression with plant growth regulators and seed primings, $GA_3$ was better expression than those with Kinetin and $KNO_3$ was better than those with PEG6000. More and clear bands were closely related to the germination rates of seeds and more detailed studies would be required.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.54-54
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• 2018

억새(Miscanthus spp.)는 우리나라 등 동아시아가 원산이며 바이오매스량이 많아 바이오에너지 원료작물로서 잠재성이 크기 때문에 2세대 바이오에탄올 생산 원료로 주목을 받고 있고, 축산깔개 및 토양개량제 등으로도 이용되고 있다. 미국과 유럽 등에서는 생태계 교란 방지를 위해 4배체 물억새(M. sacchariflorus)와 2배체 참억새(M. sinensis)의 종간 교잡 이질 3배체인 불임성 억새(M. x giganteous)을 주로 재배하고 있으나, 단일 유전형의 품종으로 병해충과 자연재해에 취약하여 다양한 억새 품종의 개발이 시급한 실정이다. 본 연구는 억새를 재료로 하여 반수체 및 배수체 확보를 통한 배수성 별 특성 평가와 함께 기내배양을 통해 탈분화 및 재분화 시스템을 구축하여 억새의 육종 효율을 높이기 위해서 실시하였다. 억새 종자로부터 캘러스의 유도는 MS배지와 N6배지에 1mg/L 2.4-D를 첨가하였을 때 비배발생 캘러스(nonembryogenic callus)가 유도되었고, N6배지에 3~5 mg/L 2,4-D를 첨가하였을 때 배발생 캘러스(embryogenic callus)가 발생하였다. MS배지보다는 N6배지에서 캘러스 유도율이 높았으며, 식물생장조절제로 2,4-D와 BA 조합처리 보다 2,4-D 단용 처리하였을 때 캘러스 유도율이 더 높았다. 억새 종에 따른 캘러스 유도율은 물억새가 25.2~49.3%, 참억새는 30.3~52.0%였고 거대억새는 62.6~81.1%로 나타났다. 억새 신초 및 줄기로부터의 캘러스 유도율은 물억새가 4.4~17.2%, 참억새는 1.8~7.7%, 거대억새는 15.3~19.9%로 나타나 종자에 비해 매우 낮았다. 미성숙화기로부터의 캘러스 유도는 억새 종에 따른 차이가 없었으며, 3mg/L 2,4-D 첨가 배지에서 캘러스 유도율이 비교적 낮았고(60~80%), 1mg/L와 5mg/L의 2,4-D가 첨가된 배지에서 캘러스 유도율이 높게(90~95%) 나타났다.

• FLOWER RESEARCH JOURNAL
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• v.18 no.1
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• pp.23-28
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• 2010

This study was conducted to determine the optimal rooting media composition and plant growth regulators for the mass production of new three cultivars in Dendrobium. Rooting medium experiments showed that shooting rate of 'Fizz' was the highest in perlite (Per) and vermiculite (V) mixture (1 : 1, v/v). Rooting rate of 'Prince' was 10% in the same treatment 60 days after cutting, while those of 'Candy' and 'Fizz' showed no shooting. With various kinds of auxin and different levels of concentrations, shooting rate in the other cultivars except 'Candy' increased highly at 60 days after cutting. Whereas, there were no differences between control and treatment except that of 'Fizz' with 200 ppm of IBA treatments showing 86.7%. Rates of cutting with leaves of 'Candy' and 'Fizz' were fairly high with 200 ppm of IBA compared to the control. Rate of rooting of 'Prince' was twice with 200 ppm of IBA or 50 ppm of NAA compared to the control. With various kinds of cytokinin and different concentrations, shooting rate of 'Candy' was 20% with 50 ppm of BA at 60 days after cutting; however, that of 'Fizz' increased in all treatments in 30 days after cutting and reached 100% with 200 ppm of BA compared to the control which was 77% at 60 days after cutting. Kinetin treatment had little effect on shooting rate compared to control at all concentrations. Treatment with 200 ppm of BA had clear effect on the rate of cutting with leaves of 'Fizz' and 'Prince', which was similar to shooting rate. However, the same treatment of BA had no effect on the rooting rate in all cultivars.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.259-262
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• 2015

We performed the following experiment to increase the development of shoots in the in vitro culture of hybrid progeny. MS medium was used as the base medium; cytokinins BA at a concentration of 2.0, 3.0, or 5.0 ㎎/L and TDZ at a concentration of 0.2, 0.3, or 0.5 ㎎/L were added to the in vitro cultures. For the FO progeny, the shoot development rate was highest of 18% with 2.0 ㎎/L BA, at 18%, and 3.0 ㎎/L and 5.0 ㎎/L BA resulted in a lower rate of 12%. TDZ addition tended to identical or similar results to that of the control media. For the FA progeny, addition of TDZ tended to lead to a higher shoot development rate and was superior with 0.3 ㎎/L treatment. However, the addition of BA to the media resulted in a shoot development rate between 14.3% and 15.7%, similar to that of the control.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.834-838
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• 2000

As an endeavor to establish a micropropagation system for Epimedium koreanum Nakai., this study was carried out to define methods to disinfect its explants and media for callus induction, proliferation and plant regeneration. The lowest infection rates by fungi or bacteria on apical and axillary bud explants of rhizome were observed when they were immerged in 0.3% NaOCl solution for 20 min after soaked in 0.1% $AgNO_3$ solution for 30 min, but leaf explants were seldom infected with fungi or bacteria by this disinfectant method. The highest rate of plantlet formation was obtained from the explants disinfected in 0.3% NaOCl solution for 20 min after soaked in 0.1% $AgNO_3$ solution for 60 min for tip buds and in 0.1 % $AgNO_3$ solution for 30 min for axillary buds of rhizome. Induction rate of callus was the highest from the explants disinfectd in 0.3% NaOCl solution for 20 min after soaked in 0.2% $AgNO_3$ solution for 15 min. Callus growth was proper in a modified 1/2 MS medium including half strength of $NH_4NO_3$ with $0.02-0.2mg{\cdot}L^{-1}$ BA and $2.0mg{\cdot}L^{-1}$ NAA. Low rate of plantlet regeneration was obtained in 1/2 UM or 1/2 White medium with $2.0mg{\cdot}L^{-1}$ BA and $0.2mg{\cdot}L^{-1}$ AA.

• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.137-157
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• 1993

This study was carried out to investigate the optimal condition for multiple propagation through leaf tissue culture and to apply anther culture techniques to Pulsatilla koreana Nakai breeding. Leaf and anther of Pulsatilla koreana Nakai were cultured on MS, MT, LS and $B_5$ media supplemented with several growth regulators and nitrogen sources under various conditions. For callus induction and differentiation from the Pulsatilla koreana leaf segments were more effective in the combination of zeatin and auxin than auxin alone. The color of the callus was green when treated with IBA alone. Shoot differentiation was more effective when treated with zeatin than auxin alone, especially the best hormoal combination for shoot differentiation was zeatin 1.0mg/l +NAA 0.1mg/l, while 2,4-D inhibited shoot differentiation. The appeared rate of S pollen was 35% in vivo, while that of S pollen by low temperature$(4^{\circ}C)$ pretreatment for 4 days was increased by 53% and the optimum culture time for callus induction from anther was uni-nucleate stage. $B_5$ basal medium supplemented with NAA 0.5mg/l and zeatin 1 mg/l was the most effective on callus formation and the best results of plant regeneration were obtained from combination of NAA 0.5mg/l and zeatin 0.5mg/l in anther culture. $NH_{4}NO_3$ as more effectives as the nitrogen source than $KNO_3$ and the combination with zeatin 2.0mg /L was the best effective. The best combination for plant regeneration in callus induced from anther was $NH_{4}NO_3$ 1650mg/l + $KNO_3$ 3800mg/l + zeatin 2.0mg/l. Ploidy level of anther-derived plants appeared 28% haploid, 47% diploid and the others were triploid, tetraploid and mixploid. In compare with E.S.T, M.D.H and P.X banding patterns were distinguished among callus, haploid and diploid plants in electrophoresis.

• Journal of Plant Biotechnology
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• v.40 no.2
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• pp.79-87
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• 2013

The aim of this study was to establish plant regeneration from leaf explants of Sedum tosaense Makino, which is globally rare and endangered species. The leaf explants of S. tosaense were cultured on the MS medium supplemented with different concentration of BA and NAA for callus induction. Callus induction was showed the highest (100%) on MS medium containing $2.0mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA. The highest number of shoots were regenerated when callus were cultured on MS medium containing $2.0mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA for 5 weeks. The axillary bud were cultured on the MS media supplemented with combination of BA and NAA for in vitro propagation. The highest number of adventitious shoot (7.9 per explants) formed at $1.0mg{\cdot}L^{-1}$ NAA and $2.0mg{\cdot}L^{-1}$ BA. For rooting, MS medium supplemented with or without $2.0g{\cdot}L^{-1}$ activated charcoal was tested. The optimal results were observed using MS medium supplemented with $2.0g{\cdot}L^{-1}$ activated charcoal, on which 85.7 (No. of root), 4.6 cm (length of root). 1,200 ppm $CO_2$ and 350 ppm $CO_2$ were supplied for make certain the effects of $CO_2$ on pre-acclimatization by photoautotrophic culture. 1,200 ppm $CO_2$ treatment was established higher than 350 ppm $CO_2$ treatment. Soil acclimatization of in vitro plantlets was the best in mixture soil consisted of peat moss and perlite with 100% survival rate and they showed the maximum growth.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.170-180
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• 2014

The aim of this study was to investigate pesticide residues in 2,877 market vegetables in the northern area of Seoul in 2013. Pesticide residues in the samples were analysed by multiresidue method for 285 pesticides using GC-ECD/NPD and HPLC-DAD/FLD. 385 samples(13.4%) were detected with pesticide residues at or below MRL, and 15 samples(0.5%) were found to detect pesticide residues exceeding MRL. The most frequently detected samples were sedum(63.6%), chamnamul(45.8%), leek(44.5%) and green&red pepper(30.8%). Among the 15 violated samples, leek(5 cases) and welsh onion(4 cases) showed the highest violation rate. A total of 74 samples(18.5%) contained multiple pesticide residues in one vegetable. Procymidone, chlorofenapyr and cypermethrin were the pesticide most frequently found. As a tool of risk assessment through the consumption of pesticide detectable agricultural products, the ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was calculated into the range of 1.05~28.61%. The results have meant that there was no health risk through dieting commercial agricultural products detected with pesticide residues.

• Korean Journal of Weed Science
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• v.17 no.3
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• pp.314-324
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• 1997

This study was conducted to investigate whether 1) photosynthetic pigments(chlorophylls and carotenoids) are formed in dodder plant(Cuscuta australis), 2) there are any characteristics in the pigment biosynthesis, compared to that of other normal plants, and 3) dodder responds to some herbicides having target site on chloroplast. 1. Chlorophyll content of dodder tendrill grown under a natural daylight was 9 times and 50 times lower than that of field bindweed stem and leaf, respectively. 2. The photosynthetic pigment contents varied in different tissues, being higher in a apical region than in a lower region of seedling or tendrill. Chlorophyll wasn't almost observed below the 4th internode from the upper. 3. Pigment contents were greatly dependent on light intensity so that there were 4 to 6 times difference among light conditions. When the shoot containning low pigment contents under natural light, was incubated in growth chamber with various light intensities, the pigment contents were increased by 3 times of initial contents at about 97${\mu}E$ $m^{-2}s^{-1}$PAR. While the change in pigment contents was not observed at above 450${\mu}E$ $m^{-2}s^{-1}$PAR 4. Exogenous supply of 5mM 5-aminolevulinic acid increased protochlorophyllide by 7 times and 1.4 times in the etiolated shoot from field bindweed rhizome and in dodder stem, respectively, showing that dodder relatively has a low response to 5-aminolevulinic acid. 5. Pigment loss was observed in the treatment of paraquat, norflurazon, oxyfluorfen and diuron, and protoporphyrin IX was accumulated by oxyfluorfen as in normal plants Based on above results, several chracteristics of pigment biosynthesis in dodder seem to be summerized as follows. Photosynthetic pigment biosynthesis in Cuscuta australis runs even in low level. The pigment contents is differentially distributed in different regions and their contents seem significantly to be controlled by light intensities. Especially, chloroplast rapidly tends to degenerate with the development of tissue. Some herbicides having target site on chloroplast induce damage to dodder stem but are unlikely to control it well in field, except paraquat, due to low chloroplast activity and parasitic mode of nutrition.