• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.1-17
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• 2000

Crystals in the woods and barks of Populus maximowiczii and Populus nigra ${\times}$ maximowiczii were examined by light microscopy, scanning electron microscopy and soft X-ray. Populus examined had the wetwood and the heartwood of Populus showed higher moisture content than in adjacent sapwood. The crystals can be detected clearly by the soft X-ray due to their higher densities than the wood. Crystals in xylem wood of Populus were found mainly at heartwood. However, they were concentrated in specific areas such as in color-stained area or along the specific annual rings. Crystals showed the highest occurrence around the pith. Within a growth ring the amount of crystals in earlywood was more abundant than in latewood. Crystals were observed mainly at vessels and fibers although they occurred at all kinds of cells in heartwood. Crystals in the bark were scattered evenly both in inner bark and in outer bark. Populus nigra${\times}$maximowiczii showed higher frequency of leaf knots than Populus maximowiczii.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.145-149
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• 2004

We investigated the anatomical aspects of vitrification in peace poplar. Comparisons were made with regard to characteristics occurring between hyperhydric and normal shoots in shoot proliferation cultures on MS medium containing 0.2 mg/L BA. Compared with normal plants, hyperhydric plants had thick, curled, and dark green leaves. Hyperhydric stems were thicker and shorter than those of normal stems. When examined under the microscopes, the mesophyll palisade cells of hyperhydric leaves were vacuolated, whereas those of normal leaves contained normal and enriched vacuole with cytoplasm. Generally, the hyperhydric leaves showed poorly developed palisade parenchyma, and revealed irregular and bigger sized intercellular structures in both palisade and spongy parenchyma as well as epidermis cells compare to those of normal leaves. In addition, the hyperhydric leaves had lower stomatal density and bigger sized cell. Vascular tissues of hyperhydic stems were less differentiated because of poorly lignified xylem tissue. The greatly expanded cortical cells and pith appeared to be the main cause of thick stems as compared with normal stems.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.66-71
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• 2004

This study was carried out to elucidate the molecular weight and the heating properties of Korean white ginseng protein by CM-cellulose column chromatography and electrophoresis. Thermostable protein contents were 0.17% in xylem-pith and 0.15% in cortex-epidermis of tap root by 90min of heating. The contents of thermostable protein were decrease after 90min of heating. By Electrophoresis, seven bands of 66, 45, 29, 24, 22, 20, 12kD were observed up to 30min of heating, but the band of 22kD was disappeared after 60min. of heating. The cationic protein content of thermostable protein fraction (28.24%) was higher than the anion protein content(0.80%). The molecular weight of thermostable protein fractions were 66kD, 55kD, 36kD and those of thermolabile protein fractions were 29kD, 24kD, 22kD, 20kD.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.133-138
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• 1988

The traditional concept of ginseng quality was investigated in relation to historical experiences. traditional quality measure and mordern analytical method. The traditional concept appears to be based on the original Korean thought of oneness in life and universe. The outside appearance such as shape and size in traditional quality measure includes the inside quality. Since certain shape and size define specific tissues. cells and biologically active substances in cells the traditional measure will he a map for analytical method to find active principles. Traditional method suggests that the balance among biologically active compounds seems to he more important than the large amount of one active compound and that the mode of active compounds in ginseng for the homeostasis of human body is the multicompound to multitarget system. Traditional method strongly suggests the importance of nitrogen compounds. especially soluble protein and heat stable protein for the balance of active principles since nitrogen compounds are more abundant in the central part (xylem-pith) that grows faster than the outer part (cortex-epidermis). The balance of physiologically active principles appeares to be meaningful in relation to the difference in traditional use of Panax species.

• Research in Plant Disease
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• v.18 no.2
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• pp.101-108
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• 2012

In 2006, pinewood nematode, Bursaphelenchus xylophilus, was isolated from about 50 years old trees of Pinus densiflora and P. koraiensis showing leaf-wilt and -drying symptoms in Gwangju, Gyeonggi-do and Chuncheon, Gangwon-do. Isolation of pinewood nematodes from sapwood of infected pine trees showed no difference in population density between tree species and among the sampling heights on the main stem. Migration of pinewood nematodes in the host tree were investigated by inoculation of red pine (P. densiflora, 3 years old) seedlings with B. xylophilus. The nematodes seemed to move in red pine seedlings prior to multiplication and it might have taken about 20 days to start multiplication and expression of symptoms including wilt and dieback. In initial time after inoculation, nematodes started migration through the cortical resin canal from inoculated site and further showed upward and downward movements. More nematodes were observed in cortical resin canal during early period of inoculation and later in resin canal of xylem and tracheid also while, the pith still remained free from nematode. The density of B. xylophilus was higher in seedlings of low-vigor with poor root growth than in seedlings of normal root growth. Seedlings showing high density of B. xylophilus exhibited stem discoloration and secondary infection by fungus at the inoculation site.