• Journal of Environmental Science International
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• v.11 no.11
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• pp.1173-1181
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• 2002

The present study was undertaken to investigate the effect of low temperature and salicylic acid(SA) on the chilling tolerance of acclimated and nonacclimated cucumber(Cucurmis sativus L.) seedlings. The acclimation phenomenon was characterized in chilling-sensitive cucumber seedlings and found to have a significant effect on the survival and shoot dry weights. The injuries experienced by the acclimated seedlings in the third leaf stage were on average smaller by half than those experienced by the nonacclimated seedlings. Chilling also caused a large increase in the free proline levels, regardless of the acclimation status. Exogenous treatment with SA(0.5mM) resulted in improved growth and survival of the nonacclimated chilled seedlings, indicating that SA induced chilling tolerance and SA and acclimation had common effects. The application of cycloheximide in the presence of SA restored the acclimation-induced chilling tolerance. The elevated proline level observed in the cold-treated and SA-treated plants was more pronounced in the light than in the dark at a chilled temperature, indicating that endogenous proline may play a role in chilling tolerance by stabilizing the water status in response to chilling. From these results it is suggested that SA provided protection against low-temperature stress by increasing the proline accumulation, and pre-treatment with SA may induce antioxidant enzymes leading to increased chilling tolerance.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.558-562
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• 2009

The growth, carbon and nitrogen status of container grown black pine (Pinus thunbergii) seedlings were examined at various levels of foliar fertilization (control, 0.1%, 0.2%, 0.3%). Root collar diameter, height and dry weight of black pine seedlings increased significantly with increasing levels of foliar fertilization (P<0.05). Carbon concentration in needle of black pine seedlings was significantly higher in the foliar fertilization than in the control treatments (P<0.05), while other seedling components such as stem and roots were not significantly different (P>0.05) between the foliar fertilization and the control treatments. Nitrogen concentration and content were significantly greater in the foliar fertilization than in the control treatments (P<0.05). Shoot/root ratio of black pine seedlings (needle+stem dry weight/root dry weight) was greater in the foliar fertilization (2.40-2.89) than in the control treatments (1.87). However, nitrogen use efficiency was significantly lower (P<0.05) in the foliar fertilization (28-46) than in the control (111) treatments. The results indicate that morphological characteristics and nutritional status on container grown black pine seedlings were enhanced by various levels of foliar fertilization.

• Korean Journal of Plant Resources
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• v.26 no.4
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• pp.503-510
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• 2013

This study was conducted to determine the optimum intensity of root pruning and the initial seedling size of 1-year-old Quercus serrata for producing 2-year-old healthy seedlings. Large( > 26 cm hight) and small size ( < 24 cm hight) seedlings were pruned their root by the length of 5, 10, and 15cm and then transplanted on nursery. Stem height, root-collar diameter(RCD), height to RCD ratio(H/D ratio), shoot dry weight(DW) and root development were measured during first growing season after transplanting. Seedling size and pruning intensity influenced on shoot growth such as height, RCD, H/D ratio and DW after transplanting. In addition, the development of lateral roots such as number, length, DW and diameter were affected by the seedling size. Taproot pruned by 15cm was shown excellent above-ground growth in large seedling group, but pruned by 10 and 15cm showed respectively better shoot growth in small seedling group. Large seedlings increased their above-ground growth, taproot regrowth, and number of lateral roots more than those of the small seedlings. But the length and DW of lateral roots were increased in the small seedlings. In conclusion, in order to produce high quality 2-year-old seedlings, it is important to produce large size of Q. serrata seedlings. Also root pruning length of 1-year-old Q. serrata was reasonable on 15 cm in taller than 26 cm or 10cm in less than the height.

• Korean Journal of Organic Agriculture
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• v.6 no.1
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• pp.127-132
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• 1997

This experiment was carried out to examine the effect of various functional materials such as bioceramic podwers, crushed shells and elvanites supplemented to the each substrate on the seedlings growth of rices. The rice seedlings were grown in pots filled with substrates supplemented with bioceramic podwers, crushed shells and elvanites. The growth of rice seedlings in terms of plant height, stem diameter, root length and leaf width, plant fresh and dry weight was promoted by adding the bioceramic powders (2 to 3g/kg), crushed shells (10g/kg) or elvanites (20 to 40g/kg). Plant height was also promoted by the adding of bioceramic powder from 16 days after treatment, whereas crushed shells and elvanites from 10 days after treatment. Especially, root growth was greatly influenced by bioceramic powder, whereas the shoot growth(leaves and stem) was stimulated by the crushed shells and elvanites supplemented into each substrate. In the field, plant growth in terms of plant height, leaf length and leaf width were also influenced by crushed shells and elvanites at 74 days after treatment. The growth of rices in terms of tiller number, spikelets, panicles and spikelets/panicle was incresed by adding the crushed shells and elvanites from 100 to 200g per m2.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.249-254
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• 1999

The effects of various levels of Al concentration on growth, nutrient status and net photosynthetic rate of 2-year-old Pinus densiflora Sieb. et Zucc. seedlings grown in a nutrient culture solution were investigated. Al concentrations were added as aluminum chloride($AlCl_3$) at 0(control), 10, 30 and 60ppm to the nutrient culture solution. The nutrient culture solution was maintained at pH 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution and grown in a greenhouse for 90 days from May 8 to August 6, 1996. The treatment above 10ppm of Al concentrations induced a significant reduction on the dry weight growth of the seedlings. The relative growth rate(RGR), net assimilation rate(NAR) and net photosynthetic rate of the seedlings were reduced with increasing of Al concentrations in the nutrient culture solutions. This result suggests that reductions in the RGR and NAR of the seedlings were mainly due to the inhibition of net photosynthesis. In addition, the increase of Al concentrations in a nutrient culture solution decreased the concentration of essential mineral elements such as Ca and Mg in the needle of the seedlings. However, the concentrations of Al of each plant organ increased in the treatment above 10ppm of Al concentrations in the nutrient culture solutions. This result suggests that the increased Al concentration in the belowground part resulted from the decreased concentration of essential mineral elements in the aboveground part of the seedlings.

• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.58-68
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• 2001

This study was carried out to investigate the growth and biomass production of Abies koreana seedlings under different relative light intensity. The 5-year-old potted seedlings were grown for 24 months under different light intensity of 100%, 50%, 30%, 10% and 2% of the natural full light intensity. The results were as follows: 1. Height growth was similar in the seedlings under different light intensities except in 2% of the full sun light intensity, having shown the lowest height growth. 2. Root collar diameter growth was reduced gradually by decreasing of the relative light intensity. 3. The seedlings which were grown under relatively low light intensity showed the later starting date of the stem growth in the next spring and showed the smaller number of new needles, and the smarter number and the shorter length of new shoot of the seedlings. 4. Total dry mass including the dry mass of leaves, shoot and root was reduced by decreasing of the relative light intensity. 5. In case of the seedling grown in one year shading condition, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.99$\pm$0.25 to 1.06$\pm$0.06 and was not significally different among the seedlings grown under 100%, 50% and 30% of the relative light intensity. And the radio was ranged from 0.60$\pm$0.04 to 0.52$\pm$0.03 in the seedlings grown under 10% and 2% of the relative light intensity, respectively. In case of the seedling grown in two years shading, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.79$\pm$0.04 to 1.00$\pm$0.03 and was not significally different among the seedlings grown under 100, 50, 30% and 10% of the relative light intensity. And the ratio was 0.29$\pm$0.03 in the seedlings grown under 2% of the relative light intensity, respectively. 6. T/R ratio of the seedlings grown in one year shading condition was ranged from 3.35$\pm$0.33 to 4.61$\pm$0.25 and was not significantly different among the relative light intensities of 100%, 50%, 30% and 10%. The seedlings grown under 2% of relative light intensity showed the highest T/R ratio of 7.36$\pm$0.15. In case of the two years shadings the T/R ratio was ranged from 1.76$\pm$0.11 to 3.12$\pm$0.19 and increased as relative light intensity decreased except 2.01$\pm$0.14 in 2% of relative light intensity.

• The Korean Journal of Ecology
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• v.20 no.4
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• pp.239-244
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• 1997

Hybrid poplar (Populus trichocarpa $\times$ P. deltoides) clones were fumigated with ozone. Fumigation was applied for 6 to 8 hours each day for approximately 3 months at ozone concentrations of 0.090 to 0.115 ppm using by open-top chambers. Growth and biomass of hybrid poplar seedlings were reduced by ozone exposure. Mean percentage of falling leaves in ozone-treated plant was 6 times higher than that of charcoal-filtered plant. Among physiological responses, rate of photosynthesis, stomatal conductance, transpiration and initial Rubisco activity were significantly lower in seedlings grown in ozone environment compared seedlings grown in charcoal-filtered air. All these physiological results supported that biochemical process to be a key feature to understand reduction in photosynthesis.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.89.1-89
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• 2003

Disease suppression by ectomycorrhizal(ECM) fungi has been demonstrated on red pine seedlings. Culturing of pathogenic fungi on petri plates containing culture filtrates of ECM fungi showed that culture filtrates of the ECM fungus Hebeloma cylindrosporum may inhibit the mycelial growth of all tested soil-borne plant pathogenic(SBPP) fungi upto 60％, In order to examine the effects of ECM fungi on SBPP fungi and on red pine seedlings, both symbiotic and pathogenic fungi were inoculated into the soil with red pine seedlings by three inoculation methods; pre-inoculation of SBPP fungi 10 days before inoculation of ECM fungi, simultaneous inoculation of both fungi, post-inoculation of SBPP fungi 60 days after inoculation of ECM fungi. Seedling mortality, seedling growth, and ectomycorrhizal formation by the combined treatments were examined and compared. Pine seedlings were dead by the pre-inoculation of pathogenic fungi, except Rhizina undulate which required 9-12 days, within 6 days after inoculation. Among pathogenic fungi tested, Fusarium oxysporum was the most pathogenic with the mortality of 44％. However, no dead seedlings were shown by simultaneous inoculation of both fungi or pre-inoculation of ECM fungi. In addition, pine seedlings treated by simultaneous or post-inoculation of SBPP fungi were relatively higher than those treated by pre-inoculation in diameter at root crown and the number of ectomycorrhizal roots. There were no significant differences among inoculation methods in root length and dry weight of treated seedlings. It means that ECM fungi somehow play a role in protecting primary roots of red pine seedlings against invasion by the SBPP fungi.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.37-37
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• 2018

We use two different methods for laboratory propagation from seed of lady's slipper orchid(Cypripedium macranthos Sw.); immature seed which also called green capsule or fully mature seed about 120~130 days from pollination. In green capsule culture, the seed pods should be collected within precisely right time. The right time of seed collection could be diverse under the wether conditions or nutritional factors of the plants. In fully matured seed culture, the more complicated procedures are needed to break the dormancy of the seed; thermal or chemical treatment. The seedlings in this study were easily germinated from immature seeds in Harvais medium; 53 days after pollination(DAP) in Cypripedium pubescens, DAP 65 in C. parviflorum and C. macranthos. The germinated seedlings were transplanted to hormone free media immediately to avoid abnormal growth of seedlings. When the seedlings have roots with a minimum length of around 2-3cm and have visible dormant buds, the seedlings were removed from the flask and stored in refrigerator for vernalization. To examine the correlation of seedlings and maternal plants, the 125 seedlings of C. macranthos were transplanted in the soil bed at a distance of 20-100 cm from mother plants on April 20. The survival rate of seedlings were 92% in 20 cm distance from the ripe plants, and 56 % in 100 cm distance. The seedlings which were transplanted near mother plants showed vigorous growth in plant height, leaf width, and especially dormant buds. Considering the existence of mycorrhiza which is a symbiotic association between a fungus and the roots of a orchid vascular, the various fungus from mother plants could affect the growth of the seedlings. These results indicate the possibility of high and stable production and practical industrialization of endangered lady's slipper orchids.

• Journal of Forest and Environmental Science
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• v.28 no.4
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• pp.212-219
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• 2012

An experiment was set to understand the seedlings growth and nodulation capabilities of five potentially important leguminous agroforestry tree species of Bangladesh in response to application of organic fertilizer. Study was carried out in nursery bed on the seedlings of Acacia mangium Willd., Acacia hybrid, Acacia auriculiformis A. Cunn. ex Benth, Albizia lebbeck (L.) Benth. and Leucaena leucocephala (Lam.) de Wit. after sowing their seeds in polybags filled with different medium. Farmyard manure or decomposed cow dung was applied as the source of organic fertilizer with other potting media. The growth and nodulation performance of seedlings of the selected species were measured three moths after the first seed was emerged. The different soil: organic manure ratios' used during the experiment were, 1:1, 2:1 and 3:1. The effects of organic fertilizer on growth and nodulation were compared to that of seedlings grown in control. The results revealed a positive correlation between seedling growth and the different doses of organic fertilization (i.e. seedling growth was enhanced significantly with different treatments containing higher proportion of organic fertilizer). In few cases a negative effect was observed after applying higher levels of organic manure. It was also apparent that the nodulation in terms of nodule number and size was inhibited significantly by the application of organic fertilizer.