• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.95-102
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• 2005

The present study was performed to investigate the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and Proly1 endopeptidase (PEP) inhibitory activities of plant extracts. The whole extract of Fragaria yezoensis inhibited the DPPH radical by $90.4\%$ and the stem of Gingko biloba, Gardenia jasminoides for. grandiflora and Rhododendron yedoensa var. poukhanene, the loaves of Rhododendron mucronulatum var. ciliatum, Gardenia jasminoides for. grandiflora and Corylus sieboldiana var. mandshurice, the fruit of Cornus officinalis, and the root of Gingko biloba showed high DPPH radical scavenging activities. In the case of PEP inhibitory activities, high inhibition was observed in the whole Plant of Fragaria ananassa, Fragaria yezoensis and Hypericum erectum, the stem of Actinidia arguta and Rhododendron yedoensa var. poukhanese, the leaves of Rhododendron yedoensa var. poukhanense and Rosa davurica, the fruit of Cornus officinalis. and the root of Acer okamotoanum. There was significant correlation (P=0.000) between DPPH radical scavenging and prolyl endopeptidase inhibitory activities, thus some of plant extracts such as whole Fragaria yezoensis, fruit of Cornus officinalis had high activities in both DPPH-scavenging and prolyl endopeptidase inhibition. Therefore, it is required to examine the mechanical interaction between DPPH-scavenging and prolyl endopeptidase inhibitory activities and further studying plant extracts with both these activities is desired to develop agents for preventing and treating of Alzheimer's disease.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.4
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• pp.82-90
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• 2001

This study was carried out to reveal optimum conditions for in vitro propagation of 3 Korean native azalea species, Rhododendron mucronulatum, R. yedonese var. poukhanense, and R. shlippenbachii, which are useful for landscape proposes. Seeds and meristems from three azalea species were cultured on 1/2MS, Hyponex, and Anderson media containing growth of regulators benzyladenine(BA) and 2-isopentenyadenosine(2ip). The results were as follows. 1. In the culture of R. schlippenbachii and R. mucronulatum seeds, in vitro seedlings germinated and grew well on he 1/2MS and Anderson media, while R. yedoense var. poukhanense on Hyponex media containing 6.0mg/$\ell$ 2ip. 2. When the meristems of R. mucronulatum were cultured on Andeson media containing 9.0mg/$\ell$ 2ip, the survival rate of meristems was 23.0% in 6 weeks after culture, and the survival rate of R. schlippenbachii was 46.0% o nthe same media containing 12.0mg/$\ell$ 2ip. The survial rate of R. yedoense var. poukhanense was 92.0% onHyponex media containing 0.5mg/$\ell$ BA and 9.0mg/$\ell$ 2ip. When the meristems of R. mucronulatum and R. yedoense var. poukhanense were cultured on Hyponex media containing 12.0mg/$\ell$ 2ip, they showed the most excellent growth. R. schlippenbachii grew well on Anderson media containing 9.0mg/$\ell$ 2ip. When in vitro shoots of R. yedoense var. poukhanense were subcultured to solid medium, they grew well in shoot growth on Hyponex media containing 6.0mg/$\ell$ 2ip.

• Journal of Plant Biology
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• v.13 no.1
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• pp.33-46
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• 1970

Pinus densiflora stands are common secondary forest communities on infertile soils in Korea. The stands are results of long severe past biotic pressure such as cutting, burning and grazing. These could be regarded as biotic climax in Korea. Because of their prevalent occurrence, relatively simple species and age composition, and their domestic economic importance, study of their distributional patterns may give some basic knowledge for better utilization of land resources in Korea. To detect distributional patterns and interspecific associations ten pine stands, each of which was homogenious with respect to topography and physiognomy, were subjectively selected from pine stands in Kyunggi Province near Seoul in 1969 and were made object of this study. Four contiguous systematic samples of count for trees, shrubs and seedlings from belt transects were collected from homogeneous areas within ten natural pine stands. The belt transect was 64m or 128m in length, and 1m, 2m or 4m in width. Basic units within the transect ranged from 64 to 256. The data from the contiguous transects were analysed in terms of multiple split-plot experiment. Departure from randomness of stem distribution, i.e., pattern, was tested in terms of variance mean ratio. For the detection of association between species, correlation coefficient was calculated for different block sizes. The values of ${\gamma}$ were tested by the usual t-test. Fine trees within one of the stands showed significant regular distribution through out the blocks. Within other eight stands pines were randomly distributed at basic unit with 4$\times$4m, 2$\times$2m, 2$\times$1m and 1$\times$1m. One significantly clumped distribution at basic unit 2$\times$2m, however, was observed from one of the pine stands. These randomly distributed groups were themselves significantly regularly distributed throughout the blocks for four pine stands. For the other four pine stands, in addition to the random distribution at the basie unit(the primary random group), randomly distributed groups with 32m dimension(the secondary random groups) were also observed. Both the primary and the secondary random groups were significantly regularly distributed at the rest of blocks. Pine seedlings were not distributed randomly thoughout the blocks. Within three of the ten stands they were contagiously distributed. Important shrub species underneath pines such as Querus serrata, Q. acutissima, Leapedeza intermedia, Rhododendron Yedoense var. poukhanenae, Juniperus utilis, Rhododendron mucronulatum var. ciliatum shnwed consistently similar distributional pattern with the pine at each stand. The shrub species pairs; Rhododendron Yedoense var. poukhanenae/Quercus serrata, Rhododendron mucronulatum var. ciliatum/Lespedeza intermedia were significantly negatively associated from 1m to 4m dimensional block sizes but became significantly positively associated from 8m sized blocks on. On the other hand the shrub species pairs; Lespedeza intermedia/Robinia Pseudoacacia, and Lespedeza bicolor var, japonica/Lespedeza intermedia were also significnalty negatively associated from 1m to 8m sized blocks but became significantly positively associated from 16m sized blocks on. The associational pattern between Rhododendron mucronul tun var. poukhanenae and Lespedeza intermedia was not consistent throughout the stands. In some stands negative associations were observed throughout the blocks except NS 32. From these observatons micro-edaphic variation within the pine stands seems not to be great enough to cause distributinal difference of pine trees within the ten pine stands. Among each species and pine seedings, however, the edaphic variation within the pine stands may be great enought to cause distributional variation.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.98-105
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• 2008

To investigate the vegetation structure of the region from Bukhansanseong to Insubong in Bukhansan National park, 16 plost$(2500m^2)$ set up with random sampling method were surveyed. Three groups Quercus mongolica-Mixed Broad leaved community, Pinus densiflora-Quercus mongolica community, Quercus mongolica community was classified (or communities were classified) by cluster analysis. Quercus mongolica were found as a major woody plant species in Bukhansan National park region. High positive correlation were proved between Quercus mongolica and Rhododendron; Quercus mongolica and Rhus tricocarpa; Rhododendron mucronulatum and Rhododendron schlippenbachi; Symplocos chinensis and Rhododendron schlippenbachii; Acer pseudosieboldianum and Magnolia sieboldii, and relatively high negative correlation was proved between Fraxinus rhynchophylla and Rhododendron mucronulatum; Juniperus rigid a and Acer pseudosieboldianum; Styrax obassia and Acer pseudosieboldianum. Species diversity(H') of investigated groups were ranged from $1.236\sim1.319$ and it was relatively high compared to those of the ridge area of other national parks.

• Korean Journal of Plant Resources
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• v.33 no.2
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• pp.106-115
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• 2020

In order to find out the relationship between spring phytophenological index and temperature index for the past nine years (2010~2018), this study identified the relationship between temperature changes and trends in spring phytophenological index of sprouting, flowering and leaf unfolding of Pinus densiflora Siebold & Zucc., Larix kaempferi (Lamb.) Carrière, Quercus mongolica Fisch. ex Ledeb., Rhododendron mucronulatum Turcz., Lindera obtusiloba Blume and Acer pseudosieboldianum (Pax) Kom. in Daegu Arboretum, Palgong mt., Juwang mt. and Gaya mt. The change in temperature was caused by an increase in the monthly average temperature between March and April compared to February for nine years, and the average temperature of Daegu Arboretum and Palgong mt. were higher by region. The sprouting, flowering and leaf unfolding were the fastest of the Lindera obtusiloba and the slowest of the Pinus densiflora for each species, and the fastest plant season in Daegu arboretum came. SPI (Spring Phytophenological Index) tends to advance by -1.267~-6.151/9 years, with the largest Pinus densiflora (-6.151/9 years), with the lowest rate of change for Rhododendron mucronulatum (-1.267 days/9 years). Species which shows significant values in sprouting, flowering and leaf unfolding is Rhododendron mucronulatum and Pinus densiflora, which correlate with the mean temperature of January to March. As a result of checking the time series change of SPI, the change rate in the four regions was all negative and the phenolocal index was all accelerating. Among them, the rate of change was greater in inland areas such as Daegu arboretum, Palgong Mt. and Gaya mt. and the rate of change was slightly lower in the case of Juwang mt., which is somewhat distant.

• The Korean Journal of Ecology
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• v.8 no.1
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• pp.53-59
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• 1985

Phenological development, flowering and leafin times of Rhododendron muronulatum and R. schlippenbachii along elevagtion were studied at Mt. Kwanak, 629m high above the sea level, in Seoul. Flowering and leafing time of the former were delayed at the rate of 2.3~3.3 days and those of the latter were of 2.0~3.0 days per 100m ascent. Phenological changes of both plant species were closely correlated with minimum air temperature first, and then soil water content and minimum soil temperature among the climatic factors. Phenological difference caused by altitude and slope direction(southeast-northwest) among the topographic factors was admitted at the high significance level, but the difference by ridgevalley was little.

• Journal of The Korean Society of Clinical Toxicology
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• v.3 no.1
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• pp.52-55
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• 2005

The plant Korean rosebay are members of the Ericaceae(Heath) family and may contain grayanotoxins, which exert toxic effects by binding to sodium channels in cell membranes. We had experience of 2 cases of Korean rose bay intoxication, who exposed to Rhododendron mucronulatum. Patients were presented to our ED with nausea and vomiting, hypotension, and dizziness or depressed mentation. The patients were performed monitoring and supportive treatment and were fully recovered within 48hours. Korean rose bay intoxication should be considered in patients with clinical evidence of gastrointestinal irritation, cardiac arrhythmias, and/or neurologic signs without identifiable causes, especially in spring or early summer.

• The Korean Journal of Ecology
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• v.14 no.3
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• pp.243-255
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• 1991

The vegetation of haenam peninsula(126 30e.l. and 34 30n.l ) was investigated from July, 1990 to 1991. the units of vegetatin were classified by the phytosociological method of broun- blanquet's. the forest vegetation was classified into 7 communities, sasa borealis-quercus acuta, cinnamomum japonicum, camellia japonica, rhododendron mucronulatum-pinus thunbergii, pinus densiflora community, torreya nucifera, chamaecyparis obtusa afforestatio, and the actual vegetation map was drawn in 1 : 50,00 scaie.

• The Korean Journal of Ecology
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• v.15 no.1
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• pp.81-102
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• 1992

The forest of kadok islet was investigated from aug. 1 1990 through oct. 30, 1990. The results obtained are summarized as follow : a floristic community. Most of the investigated area is occupied by arable land and pinus thunbergii forest, quercus serrata forest with only small area of camellia japonica forest of the eastern units. pinus thunbergii community subunit : eurya japonica rhododendron mucronulatum var. ciliatum elaeagnus umbellata typical quercus serrata community subunit : stephanandra incisa rhus chinensis typical quercus autissima community camellia japonica community zelkova serrata-acer mono community carpinus coreana community

• Horticultural Science & Technology
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• v.28 no.3
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• pp.403-408
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• 2010

This study was carried out to investigate the physiological responses of $Rhododendron$ $mucronulatum$ Turcz. and $R.$ $indicum$ (L.) Sweet seedlings with 0%, 35%, 55% and 75% shading of full sunlight in polyethylene film house. The shading treatments were performed during the late growth season for each species (from Sept. 9 to Nov. 5, 2008). The shading treatment was effective in reducing the daily temperature by 0.9 to $1.7^{\circ}C$ during September and by 0.8 to $1.7^{\circ}C$ during October. Before the shading treatments, the water content of $R.$ $mucronulatum$ and $R.$ $indicum$ amounted to 68.5% and 66.3%, respectively. The water contents of two species after 75% shading treatment period decreased to 66.2% (3.4% reduction) and 65.9% (0.6% reduction), respectively. Notably, both species had a similar tendency indicating less reduction rate of water content with 75% shading. $R.$ $indicum$ showed higher photosynthetic capacity with higher level of shading, and its photosynthetic capacity reached the highest level ($9.63{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). On the other hand, shading-treated $R.$ $indicum$ showed higher intercellular $CO_2$ concentration, stomatal conductance and transpiration rate (55% shading > 35% shading > 75% shading) than non-treated ones. In addition, non-treated seedlings showed higher water use efficiency than treated ones. In particular, it was found that the leaf color of $R.$ $mucronulatum$ turned equivalent to purple under full sunlight, while its leaf color kept equivalent more to green with higher level of shading, as evidenced even in naked eyes. According to comprehensive analysis using Munsell Color Chart on potential leaf color variations of $R.$ $mucronulatum$ depending on the level of shading, it was found that relatively many leaf colors under full sunlight were equivalent to R (red) and Y (yellow) chart, while relatively many leaf colors with higher level of shading were equivalent to G (green) and Y chart, where the latter still showed green color.