• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.141-150
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• 2015

Thirty-two actinomycetes isolates from Korean forest soil were screened for their nematicidal and reproduction suppression activity against pine wood nematode (PWN) which is widely spread in Korea. Culture filterates of 21 isolates showed more than 90% mortality at 2-fold concentration. Among them, AM210, SG16, YD116 and YD315 were more effective than others on reproduction of PWN. The YD116 isolate was identified as Streptomyces atratus by morphological and 16S rDNA analyses. Hydrazine hydrate, similar to hydrazidomycin which has cytotoxicity among substances from S. atratus against PWN, was tested for its nematicidal activity. Ten ppm of the hydrate showed 60.8% mortality. Additional studies are needed for practical use of the S. atratus YD116 isolate.

• Journal of the Korean Wood Science and Technology
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• v.37 no.6
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• pp.585-599
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• 2009

This study was carried out to investigate the antifungal activity of the water soluble essential oil against Trichoderma spp. Water soluble essential oils from Pinus densiflora and Chamaecyparis obtusa were obtained from GAP (Gas assisted process) extraction apparatus. When the water soluble essential oil was treated, the growth of the conidial germination was maximum under the cultivation condition at $25^{\circ}C$ and in the culture medium adjusted to pH 5.0. The yield of water soluble essential oil was 3.9% and 3.7% in P. densiflora and C. obtusa, respectively. 24 and 15 kinds of compounds were identified in water soluble essential oils of P. densiflora and C. obtusa, respectively. The major components in the essential oil of P. densiflora were $\alpha$-Terpineol acetate and Terpinen-4-ol and those of C. obtusa were Terpinen-4-ol and $\alpha$-Terpineol. Antifungal activity was the best in the 5000 ppm of P. densiflora against Trichoderma harzianum and in 5000 ppm of C. obtusa against Trichoderma atroviride.

• Korean Journal of Agricultural Science
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• v.51 no.1
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• pp.25-39
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• 2024

This study aimed to determine a method for restoring grasslands to forests in mountainous areas. The study was conducted in an area damaged by trampling due to construction activity and herding. Additionally, there were concerns of hindered tree growth due to the alpine region climate, characterized by the low temperatures, drying, and strong winds. Therefore, forest restoration treatments such as tillage, furrow, and shading were performed to improve growth conditions. From July 2021 to April 2023, soil temperature and moisture were monitored for each treatment plot, and changes in the initial growth and survival rate of Abies holophylla were investigated. Both soil temperature and soil moisture showed significantly higher values during the four seasons in the grassland-furrow treatment plot (p < 0.05). Compared to the grassland-control plot, the average soil temperature in winter was as high as 1.1℃, and the soil moisture in summer was as high as 20.3%. Additionally, the survival rate and relative growth rate were the largest in the grassland-furrow treatment plot. The survival rate was 87.5%, the relative growth rate in terms of height was 0.013, and the relative growth rate in terms of diameter at root collar was 0.023, indicating that furrow treatment had a positive effect on the initial survival and growth of seedlings. These results suggest that furrow treatment may be an appropriate restoration method when implementing forest restoration projects in areas where tree growth is challenged.

• Korean Journal of Plant Resources
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• v.21 no.6
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• pp.431-434
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• 2008

Dental caries is the destruction of the enamel of teeth by Streptoccus mutans. S. mutans has been isolated from human dental plaque and is associated with the initial development of enamel lesions. We have studied the antibacterial action of the fruit of Callistemon citrin us against a cariogenic bacterium, S. mutans. From the fruit of C. citrinus, piceatannol (3,3',4',5-tetrahydroxystilbene) was isolated by repeated column chromatography with $SiO_2$ and Sephadex LH-20. Its structure was elucidated by instrumental analysis using 1D-NMR, 2D-NMR and EI-MS. This compound was isolated from the fruit of C. citrin us for the first time. The anticarcinogenic activity of this compound was determined by using agar well-diffusion method and minimal inhibition concentration (MIC).

• Natural Product Sciences
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• v.22 no.1
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• pp.60-63
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• 2016

The study is a pioneering effort to determine the mineral, nutritional, and phytochemical composition and phenolic content and to determine the free radical scavenging activity of Gigantochloa levis (Blanco) Merr, a native bamboo species (locally known as "bolo") in the Philippines. Proximate analysis showed that air-dried G. levis leaves contain 15.8% ash, 22.6% crude protein, 1.2% crude fat, 29.3% crude fiber, and 19.7% total sugar. Phytochemical tests indicated the presence of diterpenes, triterpenes, saponins, phenols, tannins, and flavonoids in both the ethanolic and aqueous leaf extracts, while phytosterols were only detected in the ethanolic extract. Folin-Ciocalteu assay determined the total phenolic content in gallic acid equivalents (GAE) to be $85.86{\pm}3.71$ and $32.32{\pm}1.01mg\;GAE/100g$ dried sample for the ethanolic and aqueous extracts, respectively. The total phenolic content in quercetin equivalents (QE) was $74.44{\pm}3.11$ and $29.43{\pm}0.85mg\;QE/100g$ dried sample for the ethanolic and aqueous extracts, respectively. The radical scavenging activity of the different solvent fractions containing varying concentrations of the extract was determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ethyl acetate and 1-butanol fractions were found to have the highest radical scavenging activity. Mineral analysis via Energy Dispersive X-Ray Spectrometry (EDS) of the ash of G. levis leaves showed that Si is the major component, followed by K and Mg. These results point to the potential of G. levis leaves as a source of minerals and bioactive compounds with medicinal value.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.124-130
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• 2006

To explore the development of photoprotective mechanisms, chlorophyll a fluorescence, chlorophyll and carotenoid content and antioxidant enzyme activity in leaves were investigated at different vitality and leaf development stage of Alnus firma Sieb. et Zucc under tailing condition. The lowest maximum photochemical efficiency (Fv/Fm) in leaves of high- and low-vitality plants were observed at 12:00 pm and 2:00 pm, respectively, and the decrease of Fv/Fm in leaves of all plants were almost completely restored at 6:00 pm. Fv/Fm of full-expansion leaves was higher than that of emergence leaves at all measurement time. Chlorophyll, ${\beta}$-carotene and xanthophyll content in leaves of high-vitality plants and in full-expansion leaves were higher when compared to those of low-vitality plants and emergence leaves. Especially xanthophyll contents in both stage leaves of high-vitality plants were higher than 8.7 times and 18.8 times those of low-vitality plants. Only SOD activity was seen significant difference between leaf stage in leaves of high-vitality plants.

• Journal of Plant Biotechnology
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• v.47 no.3
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• pp.254-259
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• 2020

We studied the antioxidative and immunoregulatory properties of 70% ethanol extracts from the leaves, branches, and fruit of 13 species of the Rhamnaceae collected during the bearing season (Berchemia berchemiifolia, Berchemia floribunda, Hovenia dulcis, Paliurus ramosissimus, Rhamnella franguloides, Rhamnus crenata, Rhamnus davurica, Rhamnus koraiensis, Rhamnus parvifolia, Rhamnus ussuriensis, Rhamnus yoshinoi, Sageretia thea, and Ziziphus ujube). Total phenolic and flavonoid content values were determined using calibration curves of gallic acid and rutin, respectively. ABTS and DPPH radical scavenging assays were performed to determine antioxidative potential. Anti-inflammatory effects were studied using the nitric oxide (NO) inhibition assay in LPS-induced RAW264.7 cells. Extracts of Berchemia berchemiifolia, Sageretia thea, and Ziziphus jujuba had the highest total phenol and flavonoid content values. Extracts of Berchemia berchemiifolia, Paliurus ramosissimus, Rhamnella franguloides, and Sageretia thea had the highest ABTS radical scavenging activities. Berchemia berchemiifolia and Sageretia thea had the highest DPPH radical scavenging activities. Furthermore, extracts of Berchemia berchemiifolia, Berchemia floribunda, Paliurus ramosissimus, Sageretia thea, and Ziziphus jujuba showed strong anti-inflammatory activity through inhibition of NO production. The results of this study suggest that Rhamnaceae extracts can be used as natural antioxidants and immunomodulators.

• The Plant Pathology Journal
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• v.23 no.4
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• pp.318-321
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• 2007

Pine wood nematode, Bursaphelenchus xylophilus, causes pine wilt disease in a number of Pinus species, which is one of the most serious plant diseases in forest, Korea. In the course of a search for nematicidal substances from endophytic fungi, Fusarium oxysporum EF119 out of the 23 fungal strains tested showed the strongest activity to B. xylophilus. Two nematicidal substances were isolated and identified as bikaverin and fusaric acid. Fusaric acid showed somewhat higher nematicidal activity against B. xylophilus than bikaverin; fusaric acid and bikaverin, at $100{\mu}g/ml$, killed B. xylophilus with mortality values of 50% and 43%, respectively. In addition, both compounds acted synergistically. This is the first report on the nematicidal activity of bikaverin and fusaric acid.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.88-101
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• 2008

The aim of this study was to attempt the efficacy of antifungal activity of the wood extracts against Botrytis grey mold. Wood chip derived from Quercus mongolica was obtain from steam explosion process and extracted by hot water and methanol and ethanol. The conidial germination was maximum growth with the application temperature for 20 and $25^{\circ}C$. In pH test, we observed the maximum growth in pH 5.0 and 7.0. Antifungal activity was the best in the hot water extractives against Botrytis cinerea. The separation of the antifungal substances was performed using a silica-gel column (n-hexane : chloroform : ethyl acetate : formic acid = 12 : 17 : 8 : 0.2, v/v/v/v), TLC and UV-Spectrophotometer, and isolated 6 fraction group. The result of antifungal activity in 6 fraction group, fraction group I and fraction group II were the highest antifungal activity against grey mold with the present study. Three peaks in fraction group I and II were detected by HPLC and this compounds were suppose to effective of antifungal activity.

• Korean Journal of Ecology and Environment
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• v.47 no.1
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• pp.24-31
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• 2014

This study was conducted to clarify the seasonal and elevational pattern of herbivore's feeding pattern in a temperate deciduous forest. We investigated the herbivore's feeding activity for three years (2011~2013) at three survey sites in Mt. Jirisan National Park (Piagol, Siamjae, Nogodan). We selected target tree species based on the dominance across the sites (Quercus, Acer, Rhododendron and Carpinus) and scored herbivore's feeding activity every one or two weeks from April to June using leaf damage index. We found that the herbivory started early at the low elevation site (Piagol, ${\approx}300m$), and the highest feeding activity occurred at the mid elevation site (Siamjae, ${\approx}900m$). At the highest elevation site (Nogodan, ${\approx}1300m$), the herbivory started late, but the total feeding activity accumulated quickly. Compared to the breeding time of Varied tit, an insectivore bird, it was overlapped with the feeding activity period of herbivores, suggesting close interaction among plants, insects and birds in this deciduous forest. We suggested a need of long-term monitoring of this tri-trophic interaction since duration of herbivore activity can be changed followed by climate change.