• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.52-62
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• 1991

The toxic effect of azalea extract, expecially on cardiovascular system, is relatively unclear. The purpose of this study is to study the possible underlying mechanism and effect of toxic ingredient of azalea on cardiovascular system. The 71 healthy rabbits were divided into 10 groups : In group as preliminary study ; 4cc of normal saline was administered intravenously(N) ; 0.7gm/kg and 1.0gm/kg of azalea extract was administered respectively in the same route, volume(A1, A2) ; atropine was administered intravenously(A) ; after pretreatment with atropine(0.04mg/kg) to block parasympathetic system, azalea extract was injected like the above groups(AA1, AA2) ; normal saline, 0.7gm/kg and 1.0gm/kg of azalea extract were administered respectively with 0.2cc(1 : 1000) epinephrine(E0,E1,E2). We measured the following indices at I minute interval during first 10 minutes and then 10 minute interval during next 30 minutes : RR interval, QTc interval, maximal systolic and diastolic pressure drop with occuring time and presence of significant arrhythmia. The results were as follows : 1. The changes of RR interval, QTc interval were significantly increased in groups by Azalea extract. The blood pressure change was significantly decreased in groups by Azalea extract. There were no significant differences according to dosage of Azalea extract. 2. The changes of RR interval, blood pressure were significant differences between administration of atropine and Azalea extract after pretreatment with atropine, but not in the change of QTc interval. 3. There were no significant differences in the change of RR interval, ATc interval, blood pressure drop according to pretreatment with atropine. 4. The interaction between epineprine and Azalea extract was not noted by the effect of epineprine itself. 5. The ST change by 0.7gm/kg, 1.0gm/kg of Azalea extract was revealed in 1 case(14.0%), 7 case(100%), respectively. 6. Most of all cases with arrhthymia, ventricular tachycardia, ventricular fibrillation, were noted in the group by epineprine, except one case by Azalea extract(1.0gm/kg). It was idioventricular rhythm. In conclusion, azalea extract has negative inotropic and chronotropic effect with arrhythmogenic potential possibly through direct myocardial ischemia or injury but we cann't be absolutely exclusive of actions of autonmic nervous system, especially parasympathetic nervous system.

• Korean journal of applied entomology
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• v.37 no.1
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• pp.49-52
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• 1998

This study was carried to investigate the seasonal occurrence of Step17~initisp yr-ioide.~ Scott (Hemiptera : Tingidae) in a azalea field at Wan.1~. Chonbuk, Korea in 1994. S, pyr-ioic1c.c had LIP to four generations in Chonbuk. The peaks of adult population for each generation were late May, mid-July. late-August, iuid mid-October. respectively. S. pyrioidrs overwintered as egg stage within the midribs of the host leaves.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.1
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• pp.93-100
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• 1989

The effect of each azalea(Rhodoendron mucronulatum) pollen extract on phase I enzyme(aniline hydroxylase)was studied in this experiment. Serum aminotransferases were not changed in mice injected each azalea pollen extract, respectively compared to control group. The hepatic micros mal aniline hydroxylase activities in the presence of each azalea pollen extract were not affected in vitro. After treatment with azalea pollen water extract, hepatic microsomal aniline hydroxylase activity was increased with dose-dependent manner as compared to control group. The increment of hepatic microsmal aniline hydroxylase activity was more powerful by the treatment of water extract. As mice received aniline after pollen butanol and water extract-pretreatment once a day for 5 days, the blood and liver levels of aniline were decreased significantly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.3
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• pp.239-246
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• 1989

Preventive effect of azalea pollen extracts against aniline-induced hepatic toxicity in mice was investigated in this experiment. When the biochemical and histological changes were measured, preventive effect was more striking by treatment with water extract. After treatment with azalea pollen extracts, hepatic microsomal aniline hydroxylase activity increased as compared to control. Whereas, aniline level in serum and liver significantly decreased. The Vmax value without affecting Km value increased by the water extract treatment, the results obtained suggest that the characteristics of increase in the aniline hydroxylase activity may include induction of enzyme proteins. These data indicate that the observed preventive effects of azalea pollen extracts against hepatotoxicity is due to the induction of aniline metabolizing enzyme.

• Landscaping Tree
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• s.85
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• pp.9-11
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• 2005

봄이면 항상 아지랑이 속에 나울나울 봄바람과 함께 분홍빛 자태를 들어내며 겨우내 추웠던 흔적을 지우고 세상사 으뜸은 ''나pos; 라고 소리치는 진달래! 우리의 동산을 채우고, 우리집 마당을 채우고, 길가의 언덕까지 채우고, 내 마음의 허전함을 채우는 철쭉, 진달래 등 종류도 다양하고 품종도 다양하다. 정원수와 조경수로 많이 선호하며 몇몇 지방에서는 5월이면 철쭉 축제도 개최하는 곳이 있다. 하지만 이 아름다운 나무를 못 살게 구는 몇몇 병해충이 있으니 진달래방패벌레, 독나방, 극동등애잎벌, 철쭉떡병 등이 대표적인 병해충이다. 이들에 대한 피해현상과 방제법에 대하여 간단히 소개하고자 한다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.31-31
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• 2020

본 연구는 대표적인 봄 꽃 식물인 진달래(Rhododendron mucronulatum Turcz.)의 개화시기를 예측하기 위해 지난 9년간(2011년-2019년) 주왕산 지역에 생육하는 진달래의 식물계절자료(파열·개화·개엽·만개·낙엽)와 기상자료(일평균기온·일최고기온·일최저기온)를 토대로 이탈리아 생물기상연구소(IBMET)의 Chill Day 개화 예측모형인 생물계절모형을 실시하였다. 생물계절모형에 의한 예상 발아일간 편차의 제곱을 최소로 하는 조합은 기준온도 5℃, 저온요구량과 가온요구량은 97.94로 나타났다. 즉, 휴면해제일로부터 기준온도 5℃로 Chill Day를 누적시켜 97.94에 도달하는 날짜가 낙엽~내생휴면해제일이자 내생휴면해제일~발아기간까지의 값이며, 내생휴면해제일을 기점으로 개화일까지 102.93이 개화에 필요한 가온량으로 나타났다. 2011년부터 2019년까지 개화예상일을 기상청 회귀모형을 실관측기온에 적용한 결과 오차는 MAE=1.44이며, 생물계절모형을 적용할 경우 오차는 MAE=1.39, 기준온도 5℃일 경우 MAE=4.23, 기준온도 6℃일 경우 MAE=5.47, 기준온도 7℃일 경우 MAE=5.05로 나타나 생물계절에 의한 관측과 기상청의 회귀모형이 가장 유사한 것으로 나타났다. 가장 최근인 2018년과 2019년의 기상청 회귀모형와 생물계절모형의 개화 예측일을 비교한 결과, 2018년의 경우 청송지역의 진달래는 기상청 회귀모형에서 3월 30일 전후로 개화를 예상하였고 생물계절모형은 기준온도 5℃에 적용할 경우 내생휴면일에 가장 근접한 날은 3월 26일이였으며 이를 기준으로 가온량의 합이 102.93에 가깝게 되는 날인 4월 2일을 전후로 개화를 예측하였다. 실제 청송 주왕산의 진달래는 4월 3일에 개화를 시작하여 생물계절모형과 매우 유사함을 확인하였다. 2019년의 경우 청송지역의 진달래는 기상청 회귀모형에서 3월 25일 전후로 개화를 예상하였고 생물계절모형은 기준온도 5℃에 적용할 경우 내생휴면일에 가장 근접한 날은 3월 8일이였으며 이를 기준으로 가온량의 합이 102.93에 가깝게 되는 날인 3월 29일을 전후로 개화를 예측하였다. 실제 청송 주왕산의 진달래는 4월 5일에 개화를 시작하여 오히려 생물계절모형과 더욱 유사함을 확인하였다.

• Korean Journal of Plant Resources
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• v.37 no.2
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• pp.110-119
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• 2024

This study was conducted to provide information on the possibility of using Rhododendron micranthum as resource plant. Through polyphenol profiling of R. micranthum shoot extract, useful components were selected and the content of useful components and antioxidant activity by extraction solvent were compared. As a result, 37 polyphenol compounds were identified in R. micranthum shoot extract through LC-ESI-MS analysis. Contents by extraction solvent were compared of chlorogenic acid, astragalin, myricetin, and afzelin. Chlorogenic acid was highest at 6.57±0.12 mg/g in the ethanol extract, astragalin was 2.29±0.02 mg/g in the ethanol extract, myricetin was 4.77±0.06 and 4.52±0.27 mg/g in the methanol, ethanol extracts, and afzelin was highest at 0.10±0.01 mg/g in the methanol extract. Total polyphenol content of the R. micranthum shoot extract according to the extraction solvent was highest in the ethanol extract at 80.01±2.36 mg/g, and total flavonoid content was also highest in the ethanol extract at 78.08±3.44 mg/g. The IC₅₀ value of DPPH radical scavenging activity according to the extraction solvent of R. micranthum shoot was lowest in methanol extract at 943.57±10.68 mg/L, and the IC₅₀ value of ABTS radical scavenging activity was also lowest in methanol extract at 641.60±7.58 mg/L.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.374-378
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• 2010

Determining plant moisture characteristics is an essential study not only for cultivation, but also for ex-situ conservation. In this study, employing pressure-volume curve we examined moisture characteristics of Rhododendron micranthum, known as rare plant, with the aim of its ex-situ conservation. Several individuals growing in Mt. Worak, Youngwol-gun Yeonha-ri and Bongwa-gun Seokpo-ri were selected for this study, from which we collected leaves. The original bulk osmotic pressure at maximum turgor(${{\Psi}_o}^{sat}$)was -1.5 MPa in those of Mt. Worak and Seokpo-ri, which is somewhat lower than that of Yeonha-ri(-1.2 MPa). It appeared that the osmotic pressure at incipient plasmolysis(${{\Psi}_o}^{tlp}$) of leaves collected in both Mt. Worak and Seokpo-ri were -1.29 MPa, and -1.26 MPa, respectively, which are lower than that of Yeonha-ri(-1.02MPa). Maximum bulk modulus of elasticity($E_{max}$) was 14.0 MPa, 8.67 MPa in leaves collected from both Seokpo-ri and Mt. Worak, respectively, those value of which were approximately 3 times higher than that of Yeonha-ri(4.00 MPa). The values of $RWC_{tlp}$(Relative water content at incipient plasmolysis) of leaves collected in three areas, were roughly 83%, suggesting that Rhododendron micranthum has relatively high capability of containing water. Our finding on moisture characteristics of Rhododendron micranthum is similar to those of other Rhododendron spp. We suggest that individuals growing in both Worak and Seokpo-ri, are preferable to those in Yeonha-ri for ex-situ transplantation since those individuals are found to have better drought resistance.

• Journal of Life Science
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• v.31 no.4
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• pp.377-384
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• 2021

Researching the soil fungal community is important to understand the interaction between fungi and living plants. However, too few studies have examined the soil fungal community and their interactions with plants. Rhododendron mucronulatum, commonly known as Korean rosebay, is an important forest resource that has aesthetic, ecological, and potential pharmacological values. We used a pyrosequencing method to analyze the characteristics of fungal communities from R. mucronulatum soil samples from Biseul mountain county park, which is one of the famous places for large R. mucronulatum colonies in South Korea. We collected soil core samples in February and August at three sites in the Biseul Mountain County Park, taking into consideration the regional and seasonal conditions. We obtained 454,157 validated reads after pyrosequencing all six samples. The fungal communities from the first observation spot in August had the richest species diversity among the samples. Basidiomycota, Ascomycota, and Mortierellomycota were major phyla in the samples. Agaricales_f, Mortierellaceae, and Clavariaceae were major families in the samples. The genus Mortierella was the most dominant in all six samples. Overall, 19 genera could be associated with R. mucronulatum. Sample 1 had 109 genera in sample 1, sample 2 had 111 genera, and sample 3 had 112 genera that were uniquely identified. The samples collected in August had 28 identified genera, that existed only in summer samples, indicating a weather effect. This study can be used as basic research to understand the relationship between soil fungi and plants.

• Landscaping Tree
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• s.127
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• pp.26-27
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• 2012