• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.843-848
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• 2010

The effects of soil acidification on the photosynthetic activity of Quercus acutissima seedlings were investigated. We measured the growth and photosynthetic activity of the seedlings in relation to soil acidification. The dry weights of the seedlings were reduced according to the amount of $H^+$ in the soil. The concentrations of Al in needles at the 90 meq $H^+$ were significantly higher than those at the control. The contents of chlorophyll in needles at 90 meq $H^+$ were significantly lower than those at the control. The net photosynthetic rates of the seedlings in the acidified soil were reduced by increasing the amount of $H^+$ to the soil. The carboxylation efficiencies(CE) of photosynthesis were reduced in the seedlings grown in the acidified soil. These results suggested that the soil acidification induced the inhibition of photochemical reactions and $CO_2$ fixation of photosynthesis.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.347-351
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• 1998

Plant regeneration via organogenesis from leaf and stipule explants of micropropagated shoots of strawberry (Fragaria $\times$ ananassa cv. Suhong) was achieved. Leaf and stipule explants were detached from shoot-tip cultured shoots and cultured on MS medium with various combinations of BA and NAA under light or dark condition. Shoot regeneration from leaf explant was observed after 3 weeks in culture and was good at the high ratio of BA and NAA among various combination treatments. The highest shoot regeneration frequency from leaf explants was obtained with 1.0 mg/L BA and 0.1 mg/L NAA, in which 31.1% shoot regeneration frequency(1.7 shoots per leaf explant) was yielded. In case of stipule explants, shoot regeneration was largely affected by plant growth regulators during incubation under dark condition for initial 4 weeks but not under continuous light condition. The combination treatment with 2.0 mg/L BA and 0.1 mg/L NAA showed the most excellent shoot regeneration from stipule explants, where 44.4% regeneration frequency(4.0 shoots per explants) obtained. Regenerated shoots were rooted on MS medium with 0.1 mg/L NAA after shoot elongation, and the plantlets regenerated were transferred to soil mixtures with vermiculite and perlite for acclimation.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.1-10
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• 1987

This study was carried out to examine the influence of shading and root-cutting on the survival and growth of Pinus koraiensis seedlings. 1, The highest survival percentage of seedlings transplanted to transplanting bed appeared at the plot of 19% in shading. The 50% of the seedlings were survived if half of them were root-cutting. 2. Shoot elongation, root growth and diameter increment were the best at the plot of 100% in relative light intensity. However, those were the best at the plot with 1/4 root cutting. 3. The increase of needle fascicle number and the growth of needle surface area per seedling were the longest at the plot of 63% relative light intensity. Among root cutting treatments the 1/4 cutting plot showed the largest growth of needle areas.

• FLOWER RESEARCH JOURNAL
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• v.19 no.2
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• pp.81-88
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• 2011

Effect of concentrations of different plant growth retardants (PGRs) supplied to a recirculated nutrient solution in an ebb and flow system on the growth and development of potted Spathiphyllum 'Top-Pin' and 'Mini' was examined. Plants were planted in 10 cm diameter plastic pots filled with a mixture of peat moss and perlite (1 : 1, v/v) on 30 June 2005 and grown until 23 Sep. 2005. In a closed ebb and flow system, 50, 200, 350, $500mg{\cdot}L^{-1}$ daminozide (B-9), 10, 40, 70, $100mg{\cdot}L^{-1}$ paclobutrazol (Boundy), 5, 15, 25, $35mg{\cdot}L^{-1}$ ethephon (Florel), and 1, 4, 7, $10mg{\cdot}L^{-1}$ uniconazole (Sumagic) were supplemented to a nutrient solution at the initiation of experiment. On every irrigation, the nutrient solution containing PGRs was supplied at a 2 cm depth and kept for 15-20 minutes. The surplus nutrient solution was drained back into the tank for next irrigations. Paclobutrazol gave the most pronounced effect in inhibition of stretchiness. The greatest reduction of leaf length, fresh and dry weights of shoot, and elevated chlorophyll content were recorded in Spathiphyllum, with increasing paclobutrazol concentration. Daminozide concentration greater than $200mg{\cdot}L^{-1}$ resulted in minor stunting. The lowest concentration ($1mg{\cdot}L^{-1}$) of uniconazole showed greater leaf length, leaf width, and leaf petiole length than the control ($0mg{\cdot}L^{-1}$). Uniconazole concentration greater than $1mg{\cdot}L^{-1}$ resulted in similar plant growth as the plant in the control ($0mg{\cdot}L^{-1}$). High concentration ($35mg{\cdot}L^{-1}$) of ethephon resulted in the shortest leaf length, and the greatest chlorophyll content. Inhibition of stretchiness was observed even in the lowest concentration treatments. Among the PGRs, paclobutrazol was most effective in suppressing plant stretchiness. In both cultivars, ethephon and paclobutrazol, but not daminozide and uniconazole, significantly inhibited stretchiness. The results suggested that plant growth retardants (ethephon or paclobutrazol) selected in this study may be used as the most effective agents for inhibition of stretchiness in Spathiphyllum.

• Journal of Korean Society of Forest Science
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• v.49 no.1
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• pp.11-31
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• 1980

The morphological, anatomical and physiological traits were eximined for Populus alba ${\times}$ glandulosa which is an important planting species in Korea. The results obtained are as follows: 1. External characters in the leaf shape and chaff shape in the catkin were inherited as incomplete dominance but nectar gland was inherited as dominance. 2. Among the 15 selected clones, 9 clones were male, 2 clones female and 2 clones monoecious. 3. There were well-developed cork layers and bast fiber bundles in the bark. 4. Primordial leaves composed of 3 layers of cells and those undifferentiated into palisade and spongy parenchymas differed in its origin. 5. Leaf scare consisted of two kinds of tissues; one is connected to vascular bundle and the other not to vascular bundle. Tissues which had been connected to vascular bundle were isolated with only 2 or 3 layers of cork cells from the outside. 6. There was complicated arrangement in the vascular bundle of petioles. 7. Growth of the hybrid was sensitively influenced by external temperature, day-length and amount of light. In particular, it was apparent in height growth. 8. Flatness, loam soils and a $60{\times}60cm$ spacing might be best factors for the growth of P. alba ${\times}$ glandulosa. 9. The rooting of 15 clones was dependant upon external factors. 10. The growth of P. alba ${\times}$ glandulosa was best at around 80% of soil moisture content on the basis of plot water capacity. 11. Temperature difference between inside and outside stems below 100cm during the winter was the greatest at the south among seasons and among directions. 12. The sap movement was markedly influenced by air temperature, relative humidity in forest stand and moisture content in stem. 13. Total sugars in the cortex changed with season but did not differ in the dircetion of the stem. 14. Isoperoxidase variations in the leaf were different among 15 clones. Thus, it may be useful as a criterium for clonal identification. 15. The rate of soil moisture content decreased at a rapid slope was faster than that at a slow slope. Poor growth of P. alba ${\times}$ glandulosa at the slope was probably due to depletion of soil moisture.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.328-333
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• 1998

To obtain basic information for establishing a pest control strategy for insect pest management system, changes in the population densities of the black-tipped sawfly(Acantholyda posticalis posticalis Matsumura) and damage patterns in tree growth were investigated in national forests in Hoigok-ri, Kapyung-gun, Kyunggi-do, where the pest control measures were taken. The results obtained were as follows ; 1. The larval density in the soil of the forests where the insecticides were applied have been kept below economic threshold for about 7 years. The density was the highest in the middle of slopes and similar to the level of the early stage of the insect outbreak. 2. After the pest control by insecticides, reduction in tree height and diameter growth lasted for 2-3 years in trees defoliated by over 70%. 3. The diameter growth of the trees damaged by black-tipped sawfly recovered faster in upper stem than in the lower. 4. volume growth of the trees defoliated over 70% by the insect decreased for three to four years. The volume loss of trees defoliated by 70% and 90% was 19.6% and 54.0%, respectively. 5. Maintaining the rate of defoliation below 50%, which is the economic threshold, by chemical control measures had an effect of reducing the tree volume loss by $40m^2/ha$ as compared with a stand defoliated by 90%.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.149-157
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• 2008

We investigated chlorophyll contents and growth performances of five deciduous hardwood species growing in central temperate zone of Korean forest. Cornus controversa, Fraxinus rhynchophylla, Betula schmidtii, Prunus leveilleana, and Acer mono seedlings were grown under four different light intensity regime (full sunlight, $65{\sim}72%$, $29{\sim}40%$, and, $7{\sim}12%$ of the full sunlight) for the experiment. The chlorophyll contents of all of the species were highest in $7{\sim}12%$ of the full sunlight, while lowest under the full sunlight. The relative growth rate of root collar diameter and height were decreased with increasing shading level except for Acer mono that showed the highest relative growth rate under $29{\sim}40%$ of the full sunlight. Total biomass and root volumes of the seedlings studied decreased as the light intensity decreased with different shade levels. For Acer mono, however, the biomass and root volumes were highest in $29{\sim}40%$ of the full sunlight. The relative growth rate of root comparing to shoot decreased as shading increased, and as a result, the ratio of aboveground to belowground biomass increased. As the shading level increased, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) of most species increased.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.351-358
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• 2021

The study was investigated to compare growth characteristics, the antioxidant activity, and the triterpenoid content of two Centella asiatica cultivars ('Giant Tiger Care' and 'Good Tiger Care'). At 41 days after transplanting, lengths of leaf and petiole were significantly longer in 'Good Tiger Care' than in 'Giant Tiger Care'. However, the growth characteristics (leaf area, petiole thickness, petiole length, and weight) were greater in 'Giant Tiger Care' than in 'Good Tiger Care' at 104 days after transplanting (harvest time). Antioxidant activity and total phenol content in four extracts (WE, water extract; HWE, hot water extract; 50E, 50% EtOH extract; 70E, 70% EtOH extract) of the two cultivars were high in 70E of 'Giant Tiger Care'. As a result of the triterpenoids analysis, the major triterpenoids of the two cultivars were identified as madecassoside and asiaticoside. The total triterpenoid content was high in 50E and 70E of 'Giant Tiger Care' and 'Good Tiger Care', respectively but the total triterpenoid content was highest in Good Tiger Care'. However, at the 104 days after planting, the yield of 'Giant Tiger Care' was three times higher than that of 'Good Tiger Care'. In addition, the total triterpenoid content that can be produced in the same cultivation area (3.3m²) was 2.459mg in 50E of 'Giant Tiger Care', which was ~2.2times higher than that of 70E of 'Good Tiger Care' (1.103 mg). Thus, it is considered economical to cultivate 'Giant Tiger Care' which has the highest antioxidant activity and high total triterpenoid production per cultivation area.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.71-76
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• 2014

There have not been many studies conducted on the seedling production, especially in plug trays, of traditional medicinal plant species. In an effort to establish guide lines for seedling production, this study investigated the effect of plug cell size on the growth and development of plug seedling of three medicinal plant species. Seeds were sown in either 128, 200, or 288-cell plug trays, containing a commercial medium. Growth and development of individual seedling was generally promoted with increasing size of a plug cell in all of the three species. The greatest biomass of the seedlings gained in a plug tray was obtained in the 288-cell trays in Perilla frutescens var. acuta Kudo and Sophora tonkinensis, and the 200-cell trays in Angelica gigas Nakai. Overall growth and development of the shoot and root of a single seedling of Perilla frutescens var. acuta Kudo, except total chlorophyll and anthocyanin contents, was the greatest in the 128-cell tray. However, length of the longest root, length, width and area of the leaf, internode length, root fresh weight, and root ball formation in the 200- and 288-cell trays were not significantly different each other. In Sophora tonkinensis, although length of the longest root, stem diameter, leaf width, leaf area, shoot fresh weight, and root ball formation were not significantly different among the treatments, length of the longest root and root ball formation of a single seedling were the greatest in the 128-cell tray. Overall shoot and root growth, except total chlorophyll content, of a single seedling of Angelica gigas Nakai was the greatest in the 128-cell tray. Based on the total biomass, it is concluded that 288-cell trays are recommended for production of plug seedlings of medicinal plant species P. frutescens var. acuta Kudo and S. tonkinensis. In A. gigas Nakai, it would be more economical to use the 200-cell trays than 128-cell trays due to total biomass.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.83-89
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• 2010

We investigated the growth of cucumber plants, the uptake and use of mineral nutrients, such as $NO_3$-N, $NH_4$-N, $K^+$, $Ca^{+}^{+}$, $Mg^{+}^{+}$ and $Na^+$, absorbed from media solution, and the synthesis and distribution of soluble sugars under nutrient-deficient condition. Difference in plant growth revealed after 20 days of treatment. Nitrate uptake in nutrient-deficient condition was significantly reduced compared with nutrient-normal treatment, and its distribution was primarily in petioles, stem, roots and less in leaves. In contrast, ammonium content was markedly predominated in fast growing organs, and it was significantly different in growing leaves, expanded leaves, and roots under similar growth conditions. $K^+$, lack by deficient nutrient condition, was found in growing leaves. The $Ca^{+}^{+}$ content did not show significant difference between treatments and a substantial portion of $Ca^{+}^{+}$ remained in petioles. The $Mg^{+}^{+}$ content was significantly higher in the leaves of nutrient-normal condition compared with nutrient-deficient condition while significantly lower in stem and roots. The behavior of $Na^+$ in plant was similar to $K^+$ although its content was relatively little. The highest $CO_2$ assimilation was observed in fully expanded leaves of nutrient-normal condition, which was 1.7 times higher compared with nutrient-deficient condition. The instantaneous water use efficiency (A/E) and the A/gsratio, which is an index of leaf intrinsic water use efficiency for individual leaves, was 1.2 and 1.1 times higher, respectively. The total soluble sugar (TSS) contents were highest in leaves followed by petioles, stems and roots, and in younger leaves. The growing leaves contained about 7,200 mg $kg^{-1}$ of TSS in nutrient-normal condition whereas the TSS contents in nutrient-deficient condition were not significantly different between leaves. The $Mg^{+}^{+}$ and $NH_4$- N were positively correlated with the TSS whereas $NO_3$ - N was negatively correlated.