• Korean Journal of Agricultural Science
• /
• v.12 no.1
• /
• pp.31-36
• /
• 1985

Peroxidase banding patterns were obtained by disc electrophoresis of leaf extractions from flowering plants, R. mucronulatum, R. yedoense var. poukhanese, and R. schlippenbachii. A total of 21 peroxidase isoenzymes were resolved from these species, R. mucronulatum, P. yedoense var. poukhanese, and R. schlippenbachii. Five identical peroxidase isoenzymes were resolved in R. yedoense var. poukhanese and R. schlippenbachii. It means that there is a close relationships between two species. The peroxidase banding patterns of all three Rhododendron species were not correlated with each other on percentage total density of each band. The correlation coefficients for peroxidase band densities compared with leaf areas and leaf width/length ratios of Rhododendron plants were not significant at the 5% level. Wide variation was observed in R. yedoense var. poukhanese and R. schlippenbachii compared with R. mucronulatum.

• Journal of Plant Biology
• /
• v.26 no.1
• /
• pp.33-39
• /
• 1983

Twigs bearing floral buds of Rhododendron yedoense var. poukhanense(Ryp) and R. sinmsii(Rs), hardy species in Korea, were used to investigate the cold hardiness in relation to the developmental and anatomical characteristics, and the changes of water content. In floral buds of both species, the reproductive organs, pistils and stamens, matured within the bud scales in early ctober to prepare for a cold acclimation. The ray parenchymatous areas occupied in xylem were 41% in Ryp and 38% Rs. As the storage temperature is raised from 2 to 17$^{\circ}C$, water content increased more highly in Rs than in Ryp. Exotherm temperature of floral bud in Ryp was generally lower than that in Rs. The result supports that the higher cold-hardiness is achieved owing to the earlier maturation of floral buds, to the larger area of ray parenchyma in xylem, and to the lesser increase of water content as the storage temperature is raised.

• Journal of Environmental Science International
• /
• v.20 no.4
• /
• pp.427-434
• /
• 2011

This study characterized the full range of vegetation in a upland wetland (marshland) in Korea. Classified community types were used to describe vegetation at the marshland and adjacent areas. The communities contained 44 species of vascular plants and all species were identified into four plant community types. The Rhododendron yedoense f. poukhanense type and Lespedeza cyrtobotrya type had a high representation infacultative upland species (FU) and obligate upland species (OU), respectively. The monocot type was dominant in marshland by Miscanthuns saccharifloruc and contained 14 species. Together the three areas contained four species, with the strongest indicator species being Ranunculus acris var. nipponicus, Rhododendron yedoense f. poukhanense, Hemerocallis fulva, and Miscanthuns sinensis var. purpurascens. Shannon-Weaver index of diversity also varied among the community types (F = 18.9, df = 2), with the types FU having significantly higher value (3.467) than the others (1.125 for type FW and 1.239 for type OU).

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.2 no.4
• /
• pp.47-53
• /
• 1999

In order to elucidate physiological factors involved in causing the winter injuries of evergreen Japanese rhododendron (Rhododendron obtusum cv. Hinodegiri) and semi-evergreen rhododendron (Rhododendron yedoense var. poukhanense), these studies were conducted from late winter to early spring. The results were summarized as follows; The water potential, water content in stem, water potential and content have continuously increased in both species between February and May. In R. yedoense, shading treatment had 0.3MPa upper water potential and 3% upper water content than the control. Rhododendron obtusum, the treatments with shading had 0.9MPa upper water potential and 11% upper water content that the control. The difference of water balance by treatments could be found in vitality of stem measured by TTC test. Especially R. obtusum in the treatments with shading in has higher vitality than the control. we find that winter damage of evergreen R. obtusum was determined by whether water balance could be recovered from water deficient state during the dehardening period, or not. In order to recover of the water balance, decreasing water loss more important than increasing water supply, and that was effectively acrueved by the treatment with shading.

• Proceedings of the PSK Conference
• /
• 2000.10a
• /
• pp.220.1-220.1
• /
• 2000

• Journal of Forest and Environmental Science
• /
• v.14 no.1
• /
• pp.24-47
• /
• 1998

This study examined ecophysiological characteristics, cultivation methods and planting uses of tree and shrub species native to Kangwon province and valuable as landscape plants. The results were as followos : 1. 73 species selected as shrubs were ; Rhododendron brachycarpum, Rhododendron micranthum, Abelia mosanensis, Abeliophyllum distichum, Acanthopanax sessiliflorus, Acanthopanax senticosus, Alangium platanifolium var. macrophyllum etc. 2. 38 species selected as trees were ; Cornus controversa, Sorbus commixta, Malus baccata, Prunus padus, Acer triflorum, Acer tegmentosum, Styrax japonica, Styrax obassia, Sorbus alnifolia etc. 3. Shade-tolerant species were ; Abies koreana, Rhododendron brachycarpum, Rhododendron micranthum, Prunus padus, Sorbus commixta, Acer triflorum, Rhus japonica, Cornus kousa, Kalopanax pictus, Chionanthus retusa, Sorbus alnifolia, Magnolia sieboldii, Sorbaria sorbifolia var. stellipila, Berberis koreana, Lindera obtusiloba, Rhododendron schlippenbachii and Euonymus alatus. 4. Species growing well even in less fertile soils were ; Pinus thunbergii, Quercus dentata, Koelreuteria paniculata, Rhus japonica, Quercus acutissima, Albizzia julibrissin, Sorbus alnifolia, Staphylea bumalda, Philadelphus schrenckii, Clerodendron trichotomum, Deutzia coreana, Weigela florida, Zanthoxylum schinifolium and Lindera obtusiloba. 5. Salt-tolerant species were ; Pinus thunbergii, Quercus aliena, Prunus padus, Styrax japonica, Quercus dentata, Kalopanax pictus, Chionanthus retusa, Albizzia julibrissin, Tilia amurensis, Forsythia koreana, Lonicera maackii, Symplocos chinensis for. pilosa, Clerodendron trichotomum, Sambucus williamsii var. coreana, Abelia mosanensis, Deutzia coreana, Viburnum carlesii, Rhus japonica, Rhododendron yedoense var. poukhanense, Zanthoxylum schinifolium, Callicarpa dichotoma, Rhododendron schlippenbachii and Euonymus alatus. 6. Pollutant-tolerant species were ; Styrax japonica, Prunus padus, Quercus dentata, Kalopanax pictus, Chionanthus retusa, Gleditsia japonica var. koraiensis, Styrax obassia, Forsythia koreana, Kpiraea salicifolia, Clerodendron trichotomum, Viburnum sargentii, Viburnum carlesii, Weigela florida and Rhododendron yedoense var. poukhanense.

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

• Proceedings of the PSK Conference
• /
• 2000.04a
• /
• pp.172.3-173
• /
• 2000

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

• Applied Biological Chemistry
• /
• v.46 no.2
• /
• pp.144-149
• /
• 2003

Extracts were obtained from the flower of Rhododendro yedoense var. poukhanense. (7 kg) in 80% aqueous MeOH and successively fractionated with solvent of EtOAc, n-BuOH and $H_2O$, successively. Silica gel and ODS column chromatographies of the EtOAc and n-BuOH fractions were repeatedly carried out by using the various solvent systems to give five terpenoids. Chemical structures of the isolated terpenoids were determined as $2{\alpha},3{\beta}-dihydroxylolean-12-ene$ (1), ursolic acid (2), grayanotoxin IV (3), grayanotoxin I (4) and grayanotoxin III (5) based on the interpretation of several spectral data including 2D-NMR such as $^1H-^1H\;COSY$, HMQC and HMBC.