• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.382-388
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• 1988

Improvement of productivity by forest tree breeding work in Korea was estimated for a few important tree species. Progenies of 17 plus trees of red pine (Pines densiflora) outgrew by 57 percentage compared with progenies of unselected trees at age 15. If best three families are selected among the 17, more than double in volume grow-th is expected. The hybrid Pinus rigida ${\times}$ P. taeda showed more than double volume growth compare to P. rigida at a southern plantation at age 15. However, the superiority of the hybrid decreased at northern plantations, mainly because of low coldhardiness of the hybrid. At a northern plantation, the hybrid grew less than the P. rigida on upper hill, while the hybrid grew much better than the P. rigida on flat area. Another hybrid Populus alba ${\times}$ P. glandulosa grew faster than both parents by two to two and half times according to planting sites at age 10. Introduction of Pinus rigida also showed increased volume growth. Volume increase by selection of best five provenances among 45 at age 12 was estimated as 53 percent compare to progenies of plus trees in Korea, Additional 19 percent of volume increase was expected by selection of the best families within the best provenances. Annual production of chestnuts reached about 70,000 M/T by planting resistant clones to chestnut gall wasp (Dryocosmus kuriphilus), which killed almost all susceptible trees. Although polyploid trees and mutants have been produced by colchicine treatments in over 10 tree species, none of them is economically important Remarkable improvement of productivity is expected by biotechnology in future through selection, hybridization, introduction of foreign genes at cell, cell organelle and gene level, and gene transformation. At present, mass propagation of superior planting materials by tissue culture will increase the productivity.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.668-675
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• 2017

To assess the physiological effects of Aruncus dioicus var. kamtschaticus extract on cytoxicity of a neuronal cell line, antioxidant activity, and neuroprotection against intensive glucose-induced oxidative stress were quantitated. Compared to the other fractions, the ethyl acetate fraction of Aruncus dioicus var. kamtschaticus (EFAD) showed the highest total phenolics and flavonoids. The 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay and malondialdehyde inhibitory effect test confirmed the superior antioxidant activity of EFAD. Moreover, EFAD also decreased the intracellular ROS level and suppressed neuronal cell death against intensive glucose- or $H_2O_2$-induced oxidative stress. Additionally, assessment of ${\alpha}$-glucosidase and acetylcholinesterase inhibitory activities revealed that EFAD was an effective inhibitor of ${\alpha}$-glucosidase and acetylcholinesterase. Finally, high-performance liquid chromatography analysis identified caffeic acid as the main ingredient of EFAD. Overall, these results suggest that the EFAD is a good natural source of biological compounds that counteract hyperglycemic neuronal defects.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.508-514
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• 2016

Effects of the ethyl acetate fraction from gomchwi (Ligularia fischeri) extract against high $glucose/H_2O_2-induced$ oxidative stress and in vitro neurodegeneration were investigated to confirm the physiological property of the extract. The ethyl acetate fraction of gomchwi extract showed the highest total phenolic contents than the other solvent fractions. An anti-hyperglycemic activity of the ethyl acetate fraction was evaluated using the ${\alpha}-glucosidase$ inhibitory assay, and the half maximal inhibitory concentration ($IC_{50}$) value for ${\alpha}-glucosidase$ was found to be $727.64{\mu}g/mL$. In addition, the ethyl acetate fraction showed excellent 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt radical scavenging activity, and inhibition of malondialdehyde production. The ethyl acetate fraction also decreased intracellular reactive oxygen species, whereas neuronal cell viability against high glucose/$H_2O_2$-induced cytotoxicity was found to be increased. Finally, 3,5-dicaffeoylquinic acid as a main phenolic compound in the ethyl acetate fraction was analyzed by high-performance liquid chromatography. These results suggest that gomchwi might be a good natural source of functional materials to prevent diabetic neurodegeneration.

• Journal of Korean Society of Forest Science
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• v.75 no.1
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• pp.46-50
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• 1986

One-year-old seedlings of open-pollinated progenies of pitch-loblolly hybrid pine plus trees were selected for cold-hardiness during cold winter of 1983-1984. Survived trees were planted in three locations. Two years later, the ratio of cold-damaged trees and 3rd year heights were recorded. The ratio of the, cold-damage trees among screened progenies were 5.6% in Kyunggi and 22.6% in Chungnam, while 9.3% and 43.3%, respectively, in unscreened control plot. Severely damaged families at one-year-old seedling stage also suffered heavy cold damage after two years. Not much differences were observed between families in 3rd year height.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.765-769
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• 2015

Anaplasma species are obligate intracellular pathogens that can cause tick-borne diseases in mammalian hosts. To date, very few studies of their occurrence in Korean native goats (Capra aegagrus hircus) have been reported. In the present study, we investigated Anaplasma infection of Korean native goats on Jeju Island, Republic of Korea, and performed phylogenetic analysis based on the 16S rRNA gene sequences. Our results showed that Anaplasma infection was found mostly in adult female goats. The phylogenetic tree revealed that the 7 sequences identified in Korean native goats could belong to Anaplasma sp. and were distinct from A. marginale, A. centrale, and A. ovis. The results indicated that the sequences identified to belong to Anaplasma were closely related to sequences isolated from goats in China and were clustered within the same group. To our knowledge, this is the first study to detect Anaplasma sp. infection in Korean native goats.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.47-55
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• 2011

This study investigated mineral element concentrations of acorns in Quercus acutissima and Quercus serrata seed orchard, so that to estimate the variation of these species based on the chemical composition in different clones from plus trees. The acorns were collected from ten clones of each species grown in the same clonal seed orchard. The nutritional concentration of acorns was significantly different between the clones and species. The concentration of nutrient for the whole acorn followed in this general sequence: P > K > Na > Mg > Ca > Mn > Fe > Zn > Cu. The mineral concentrations of acorns in clones of Q. acutissima and Q. serrata contained P (494 to 684 and 541 to 672 mg/100 g), K (114 to 569 and 140 to 251 mg/100 g), Na (57 to 121 and 49 to 85 mg/100 g), Mg (29 to 37 and 26 to 42 mg/100 g), Ca (10 to 53 and 26 to 68 mg/100 g), Mn (0.5 to 3.4 and 1.8 to 4.5 mg/100 g), Fe (0.7 to 1.1 and 0.0 to 2.2 mg/100 g), Zn (0.34 to 0.81 and 0.38 to 0.84 mg/100 g), and Cu (0.13 to 0.40 and 0.09 to 0.34 mg/100 g) respectively. Even though acorns of Q. serrata are smaller in size than Q. acutissima, acorns of Q. serrata contained significantly higher concentration of phosphorus, calcium, iron and manganese than Q. acutissima. Based on the mineral composition of the acorns, this study has shown that the clones of Q. acutissima and Q. serrata have different ability to accumulate mineral nutrients which could indicate the variation of Quercus species in terms of mineral acquisition and accumulation.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.303-315
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• 2018

Bonsai is part of export forest products in Korea. Demand for bonsai exports to other countries is growing but the need for quarantine hazards must be eliminated in other to export. Plant parasitic nematode is also an important factor in quarantine. The nematodes were surveyed from bonsai farms in 6 areas of Korea. The surveyed deciduous bonsai plants were Acer palmatum, Zinnia elegans, Ligustrum obtusiflium, Carpinus turcaninowii, and Malus sieboldii. Three plant parasitic nematodes (Hemicyliophora koreana, Rotylenchus blothrotylus and Xiphinema americanum) and three non-parasitic nematodes (Aporclaimellus donghwaens, Egtitus andhricus, and Mesodorylaimus usitatus) were isolated from bonsai. Non-parasitic nematode, Mesodorylaimus usitatus was isolated from all surveyed bonsai trees. Only two species of quarantine nematodes (Hemcylicopora koreana and Xiphinema americanum) were found from bonsai. A. donghwaens and M. usitatus were isolated from root of bonsai tree. However other nematodes were isolated from soil in bonsai trees.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.329-332
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• 1999

The objective of this study was to determine the influence of grafting timing, rootstock cut timing and leaf removal with promalin ($GA_{4+7}+BA$) treatments on the maiden tree growth, lateral development and flower bud initiation. In mid-March 1997, two-year-old M.9-T337 rootstocks selected with trunk diameter over 1 cm were planted in the field. Chip budding with 'Fuji' scion on M.9-T337 rootstock budded in mid-April was earlier in sprouting than chip budding in mid-June. Late cutting chip budding (LCCB) with 'Fuji' scion on M.9-T337 rootstock was lower in the failed budding percentage with 14% than that of early cutting chip budding (ECCB). Especially, ECCB in April was not suitable for scion growth such as uniformity with high percentage of failed tree. Grafting timing in mid-June and rootstock cutting timing of LCCB induced more branches and flower buds than other treatments. Removal of 8 to 10 uppermost immature leaves on central leader stem and application of Promalin 250 mg/L after every 30 cm of terminal growth produced a 189 cm tall tree with 9 flower buds and 14.2 short lateral shoot from 30 to 35 cm long in length in 1998. Promalin increased branching on second-season growth and, when combined with leaf removal, resulted in uniform distribution of branches along the central leader stem.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.666-675
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• 2020

This study investigated mechanical characteristics of pine trees in Yeongdong (Goseong-gun), Yeongseo (Hongcheon-gun), and Yeongnam (Bonghwa-gun) to define differences in the material quality among pine trees of the three regions. The compressive strength, hardness and shear strength of pine trees of each region were measured. There were no differences in the compressive strength of the juvenile woods among the regions, while the heartwood and sapwood in Bongwha generally showed the highest compressive strength followed by those in Hongcheon and in Goseong. The hardness of the cross-section of pines in Bonghwa was the highest, and in terms of the hardness of the radial and tangential sections, pines in Goseong topped the list.. There were no difference among heartwoods of each region in terms of the shear strength, but, but sapwood from Bonghwa had higher shear strength than those of the other two regions, which may be attributed to differences in tracheid length and microfibril angle among pines in each region. This study identifies the quality differences among pines of different region, and therefore, is expected to add value by helping choose the domestic pine tree material effectively and selectively, and also select a plus tree.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.55-60
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• 2001

The efficacy of petroleum spray oil (PSO; D-C Tron $Plus^{(R)}$) against spirea aphid (Aphis citricola) and two scales (lcerya purchasi and Planococcus cryptus) on citrus was tested in Jeju, Korea. The control value of 0.33% PSO against spirea aphid was over 90% at 3 and 6 days after treatment (DAT), and then decreased to about 80% at 9 and 14 DAT. Spraying of PSO (0.33, 0.66, 1%) against cottony-cushion scale showed a much lower control value (less than 50%) during the investigation period compared to that of the conventional pesticide (Methion). When used against tile scale, Planococcus cryptus, the control value of 1% PSO was 95%, but that of 0.33% and 0.66% PSO only ranged from 50 to 80%, lower than the conventional pesticide. The results of this study, as with a previous study, suggest that spraying of 0.33% and 0.5% PSO not only controls the spirea aphid, but also reduces the density of two scales (lcerya purchasi and Planococcus cryptus) on citrus tree in Jeju, without phytotoxic damage.