• Journal of Plant Biology
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• 제28권3호
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• pp.243-251
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• 1985

The activity of Daucus carota L. root $\beta$-glucan synthetase II was observed to increase in the presence of polyamines such as putrescine, spermidine and spermine in vitro, whereas the activity of Daucus carota L. root $\beta$-glucan synthetase I was not affected by the polyamine. The activity $\beta$-glucan synthetase II from Daucus carota L. root protoplasts cultured on medium containing 10-6 M polyamines such as putrescine, spermidine and spermine was observed to be higher than that of the control. Daucus carota L. root protoplasts were observed to have the activities of arginine and ornithine decarboxylases and it was noted that they could produce polyamines, which might have an effect on $\beta$-glucan synthetase II activity.

• Journal of Plant Biology
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• 제34권4호
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• pp.311-316
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• 1991

The origin of cambial initials from procambium was studied in the seedling root of Acer saccharinum. In transverse view, the first periclinal divisions of procambial cells occurred just outside of each early metaxylem and resulted in meristematic strips. As root development progressed, the division activities appeared subsequently outside of each late metaxylem and then in pericycle cells opposite the four protoxylem poles. Eventually, such meristematic strips were connected completely each other. Thus, a nearly rectangular shaped meristematic layer in outline was formed outside the xylem in a whole root transectioned. In tangential section, early procambium showed a homogeneous structure consisted of uniform short cells with transverse end walls. However, some of the procambial cells did elongate, whereas others divided transversely. The former become more elongate, tapered, and vacuolated. Finally, they differentiated into fusiform initials. Short cells consisting axial strands divided continuousely in transverse plane and became ray initials, while some short cells elongated and transformed into long cells. The early ontogeny of vascular cambium in Acer saccharinum root was interpreted to be established by a gradual process.

• 한국작물학회지
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• 제24권4호
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• pp.12-18
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• 1979

간척답에서 생육한 수도의 근군의 형태 형성을 알기위하여 간척답과 숙답에서 재배된 수도의 근군을 채취하여 비교·검토한 결과를 요약하면 다음과 같다. 1. 간척답에서 생육한 수도 의 근군은 작토의 표층부에 밀집되어 있는 상태였으나, 숙답에서 생육한 수도의 근군은 작토의 심층부까지 균일하게 분포되어 있었다. 2. 간척답에서 생육한 수도의 근군 발달은 숙답에서 생육한 수도의 근군보다 불량했다. 이와 같은 경향은, 특히 이식 직후 출근하거나 관근의 원기가 형성되는 하위 요소에서 뚜렷하게 나타났다. 3. 재배 토양에 관계없이 유수형성기 이후에 출근하는 요소에서는 생장중지형 관근이 점하는 비율이 생육 초·중기의 그것보다 높았다. 4. 분기근의 형성밀도는 수도의 생육후기에 출근하는 관근을 제외하고는 간척답에서 생육한 수도가 숙답에서 생육한 수도보다 높았다.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.637-647
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• 1997

The purpose of this study was to evaluate the effect of concentration and pH of lactic acid on the formation of artificial root caries lesions formation in bovine teeth. The characterictics of artificially produced early root lesions were observed with polarized light microscope and the depth of lesions were mearsured with measuring microscope The results were as follows: 1. In the group of low pH and high concentration of lactic acid, the progress of lesion formation was faster than that of high pH and low concentration lactic acid group. 2. In the same group, initial lesion progress faster, but progression rate was reduced as time goes by. 3. In the development of initial root caries, cementum was act as a barrier to protect dentin from lesion progression.

• The Korean Journal of Ecology
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• 제23권4호
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• pp.323-329
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• 2000

The allelopathic effects of volatile substances from Chamaecyparis obtusa (S. et Z.) Endl. were examined on the germination and seedling growth of some plant species, and on the population growth of some microorganisms. The germination and seedling growth of the receptor plants were suppressed more severely by leaf and fruit essential oils than by those of other parts. Colonial growth of fungi was severely inhibited by essential oils extracted from leaves and fruits. The development of root hairs of the receptor plants was also severely inhibited by the essential oils. The cortical cells at the root tips of Lactuca sativa L. treated with essential oils showed contraction of the cytoplasm, resulting in plasma membranes becoming detached from the cell walls and the cells metamorphosing irregularly. Accumulation of lipid granules inside the contracted cytoplasm and degeneration of mitochondrial cristae were also observed.

• Journal of Ginseng Research
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• 제27권4호
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• pp.178-182
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• 2003

Vesicular-arbuscular mycorrhizae (VAM) fungi naturally colonise American ginseng roots and this relationship is highly beneficial to enhance plant productivity. Our goal was to determine the effect of adding two Glomus species (Glomus etuticatum, G. intraradices) on survival, photosynthetic capacity, growth, morphology and root ginsenoside content of one-year-old American ginseng plants grown in a broadleaf forest. While our study revealed that VAM inoculations significantly affected root morphology and Re ginsenoside content, the survival, photosynthetic capacity and root growth of American ginseng plants were not significantly influenced by VAM inoculations. Surface area and volume of rootlets were 16-25% higher for ginseng grown in VAM-inoculated soil compared to those grown in the control plots. Also, Re ginsenoside content was 18 ％ higher in YAM-inoculated roots compared to controls.

• Journal of Ginseng Research
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• 제8권2호
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• pp.82-90
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• 1984

The Present study was undertaken to obtain the basic information on the development of multistem varieties of ginseng. The root weight per plant of multi-stem ginseng was hi燥or than that of single stem ginseng, and it was found that the greater variance due to the growing area was clear in the frequency of multistem plant. The broad heritability estimate for the number of steams was lower with the increase of the age of ginseng. The number of stems per plant was positively correlated with the number of branch roots, number of dormancy buds, and root weight. However, the root diameter was negatively correlated with the number of stems is per plant. Based on path analysis, the number of branch roots and dormancy buds showed the maximum indirect positive effects on the number of stems.

• 한국초지조사료학회지
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• 제40권3호
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• pp.190-195
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• 2020

Cadmium (Cd) toxicity is a serious limitation for agricultural production. In this study, we explored tolerance mechanism associated with Cd toxicity tolerance in alfalfa plants. We used three distinct alfalfa cultivars M. sativa cv. Vernal, M. sativa cv. Zhung Mu, and M. sativa cv. Xing Jiang Daye in this study. Cd showed declined chlorophyll score in Xing Jiang Daye compared with Zhung Mu and Vernal. No significant change observed among the cultivars for root and shoot length. Atomic absorption spectroscopy analysis demonstrated a significant accumulation of Cd, Fe, S and PC in distinct alfalfa cultivars. However, Zhung Mu and Xing Jiang Daye declined Cd accumulation in root, where Fe, S and PC incremented only in Zhung Mu. It suggests that excess Cd in Zhung Mu possibly inhibited in root by the increased accumulation of Fe, S and PC. This was further confirmed by the response of Fe (MsIRT1) and S transporters (MsSULTR1;2 and MsSULTR1;3), and MsPCS1 genes associated with Fe, S and PC availability and translocation in roots and shoots. It suggests that specially the transcript signal inducing the responses to adjust Cd especially in Zhung Mu. This finding provides the essential background for further molecular breeding program for forage crops.

• Journal of Forest and Environmental Science
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• 제38권1호
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• pp.38-47
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• 2022

Hymenodictyon orixensis (Roxb.) Mabberley (locally known as Bhutum in Bangladesh) is both an ecologically and economically valuable multipurpose tree species for afforestation and reforestation programs in Bangladesh. Seed germination and seedling development study of H. orixense were conducted to find out the response to different growing medium, e.g., polybag (15×10 cm (T₀) and 20×15 cm (T₁)), sand medium in propagator house (T₂), conventional nursery bed (T₃), and root trainer (T₄) in the Nursery. Consequently, germination behavior and seedling morphological parameters of H. orixense were assessed. The results revealed that the sand medium of the propagator house (T₂) provided the highest germination % (58.57±22.30) and the highest germination energy (11.43±2.43) followed by seedlings growing in 20×15 cm polybags (T1) containing forest topsoil and cow-dung at a ratio of 3:1. Except for germination energy, germination values, and germination capacity, other seed biology parameters, particularly imbibition, germination period, germination rate, and plant survival percent in T₁, T₂, T₃, and T₄ were significantly (p<0.05) different from T₀. Each phenotypic parameter of seedlings and dry matter of shoot and root significantly differed from control except root length (p<0.992). Based on this study, Polybags of 20×15 cm size are regarded as the best medium for quality seedling development of H. orixense. The nursery bed (T₃) had the lowest germination performance and developed more inferior quality seedlings. Thereby, 20×15 cm size of polybags with conventional soil and cow-dung media is recommended for maximum germination and to grow the quality seedlings of H. orixense in the Nursery.

• 한국약용작물학회지
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• 제2권2호
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• pp.114-120
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• 1994

최근 생약의 수요 및 재배면적이 증가됨에 따라 약초의 재배기술 확립이 요청 되고 있는바 추대로 인한 수량감소와 품질저하가 크다고 알려진 강활에 대하여 파종방법별로 육묘기 생육과 묘크기에 따른 추대 및 수량성을 구명하고자 시험한 결과는 다음과 같다. 1. 파종방법별 출아율은 파종량이 적고 산파했을 경우에 높아지는 경향을 보였고 묘크기에 있어서는 파종량간에 대차 없었으나 파종방법간에는 조파구에서 생장량이 많은 경향이었다. 2. 묘 분포비율은 중묘>소묘>대묘의 순으로 많았는데 소묘생산을 위해서는 산파로서 밀파$(8l\;/33m^2)$ 하는 것이 유리 한 것으로 나타났다. 3. 묘크기에 따른 정식후 생육은 묘의 근경이 굵을수록 개화가 빨라지는 경향이었고 지상부 생육은 조파 소묘 정식이 좋은 경향이었다. 4. 묘크기에 따른 추대율은 대묘 89.6%, 중묘 64.4%, 소묘 36.9% 로 묘가 클수록 높았다. 5. 묘크기에 따른 근비대는 미추대근이 추대근에 비하여 많았고 조파묘보다 산파 묘가 좋았다. 6. 생근수량은 산파 소묘 정식구에서 853kg/10a 으로 가장 증수하였다.