• Research in Plant Disease
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• v.26 no.3
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• pp.179-182
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• 2020

In July 2018, a serious rust symptom was found throughout the fringe trees planted in Gangjin-gun, Korea. Yellow and brown spots were observed on the adaxial (topside) surface of the collected fringe tree leaves, and yellow color aecia were observed on the abaxial (underside) surface leaves. The size of aeciospore and urediniospores of JCK-KCFR1 strain were measured to 41.2 ㎛ (Φ) and 28.84 ㎛ (Φ) with a light microscope. Phylogenetic analysis of the small subunit rRNA, internal transcribed spacer, and large subunit rRNA region indicated that JCK-KCFR1 strain is novel species of the genus Puccinia and closely related to Puccinia kusanoi, which has been reported a rust pathogen on bamboo. In May 2019, rust symptoms were also discovered on the bamboo leaves planted around the fringe tree on Muwisa-ro, and their telia and teliospores were observed on the abaxial leaf surfaces of the bamboo with 100% sequence homology with the rust of the fringe tree. This is the first report that Puccinia sp. JCK-KCFR1 is a new species that requires both primary (fringe tree) and alternative (bamboo) host plants to complete its life cycle in Korea.

• The Korean Journal of Ecology
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• v.27 no.3
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• pp.185-192
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• 2004

Vegetation established through the natural process, such as Quercus mongolica, Pinus densiflora, Q. variabilis, Q. acutissima, Carpinus laxiflora, Q. aliena and Q. serrata communities and artificially introduced vegetation, which are composed of Larix leptolepis and P. rigida plantations, are established in the mountainous land of the Mt. Songnisan National Park. On the other hand, the developed lands, which are consisted of agricultural folds, residential areas, commercial areas related to tourism, etc. appear in the lowland around streams. Based on the spatial distribution of vegetation, the southern district, which is attributed to Naesongni-myun by administrative system, showed higher natural degree and vegetation diversity. However, most of the other districts, which are attributed to Cheongcheon- and Chilseong-myuns, are covered with the Korean red pine forest, a product of artificial influence, and plantation also occupied higher percentage. Thereby both vegetation diversity and natural degree are lowering. A result of ordination by DCA showed that sands tended to be arranged by depending on the topographic condition. Species diversity of plant communities was higher in broad-leaved stands rather than in coniferous ones and in stands of the early stage than in ones of the late stage. The result of analysis on vegetation dynamics implied that vegetation of this region would be dominated by Carpinus laxiflora, Quercus mongolica and Pinus densiflora communities in the future. However, considered occurrence the of disturbance and response of vegetation on that, this estimation may different somewhat from an actual situation. Conservation strategies of the Mt. Songnisan National Park were discussed in viewpoints of landscape ecology, and conservation of major plant communities and biodiversity.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.116-123
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• 2014

The description of vegetation cover and floral composition was undertaken in terms of phytosociological study in Dodamsambong(scenic site no. 44) and Danyangseokmoon(no. 45). In this study a total of 17 $relev{\acute{e}}s$ containing 144 taxa were collected and analyzed. Eight plant communities are differentiated, grouped into 4 physiognomic types: forest type(Buxus microphylla var. koreana-Thuja orientalis community, Tilia mandshurica-Quercus variabilis community, and Cynanchum wilfordii-Pinus densiflora community), mantle type(Cardamine leucantha-Neillia uekii community), secondary meadow type(Galium kinuta-Spodiopogon sibiricus community, Diarthron linifolium-Zoysia japonica community), and crevice type(Patrinia rupestris-Selaginella stauntoniana community, Hypodematium glandulosopilosum community). The vegetation of Dodamsambong and Danyangseokmoon is characterized by local flora, such as calciphilous plants, geological distribution-limit species, and endemic species. The soil depth, slope, and human impact have been identified as the most important differentiating ecological factors. Buxus microphylla var. koreana-Thuja orientalis community, Tilia mandshurica-Quercus variabilis community, and Patrinia rupestris-Selaginella stauntoniana community were evaluated highly by National Vegetation Naturalness. In order to restore the value of specific landscape for scenic site, we should improve the problems of protected area such as wrong management on habitat, forest fragmentation by facilities and decline in vegetation by lack of growing the next succession.

• Research in Plant Disease
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• v.22 no.1
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• pp.25-31
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• 2016

During a field survey in 2014, a Rorippa palustris plant showing virus-like symptom was collected from a pepper field in Dangjin in Korea. The collected sample was subjected to examine infection with pepper-infecting viruses. Molecular diagnosis assay showed that the collected R. palustris sample was co-infected with Pepper mild mottle virus (PMMoV) and Cucumber mosaic virus (CMV). This is the first identification of PMMoV from R. palustris and the first report of CMV infection of R. palustris in Korea. To examine phylogenetic positions of the identified PMMoV and CMV isolates, their complete genome sequences of were determined and compared with those of previously reported isolates of the cognate viruses. Phylogenetic analyses revealed the isolates of PMMoV and CMV obtained from R. palustris are closely related to the pepper isolates of the cognate viruses. Our results suggest that R. palustris could act a weed reservoir of PMMoV and CMV.

• Research in Plant Disease
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• v.14 no.2
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• pp.79-84
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• 2008

A wilt disease on lettuce was observed in 2006 and 2007 in commercial plastic house at main production areas of lettuce in Icheon, Yongin and Goyang of Gyeonggi Province. The disease was characterized by the wilting of lower leaves, accompanied by stunting symptoms of the whole plants. Old affected stems showed the black streak in the vascular system. The pathogen, Fusarium oxysporum f. sp. lactucae was isolated from stems and roots of diseased plants. Isolated pathogen also produced the microconidia and macroconidia with chlamydospores on carnation leaf agar medium. The pathogen easily invaded and made many chlamydospores on the roots of lettuce and also made dark streaking through the vascular in the lettuce stems. The density of Fusarium sp. in the severely diseased field soil was more higher populations than that in the healthy and less diseased field soil. The minimum population of pathogen would be above $10^3$cfu/g soil to induce the Fusarium wilt on lettuce in plastic house. The results of pathogenicity test showed 'Sunpung' and 'Mipungpochap' was high susceptible to Fusarium pathogen isolates while some cultivar 'Mihongjeokchukmyeon' and 'Jinjachukmyeon' showed moderate resistance. Disease development for some lettuce was related to treated temperature, so the symptom was more severe above $25^{\circ}C$. Selection of appropriate lettuce cultivar and planting time should be related for the successful control of Fusarium wilt.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.205-214
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• 2014

The purpose of this study is to suggest vegetation management method as the cultural landscape forest of Dongbaek Island which is the district monument. The study area was $20,000m^2$ around the peak area in management as the nature sabbatical area. Vegetation structure type was classified with the criteria of topography, vegetation, management and the management plan was derived from the vegetation structure analysis according to the types. Vegetation structure types were Management-Camellia japonica, Non-management-Eurya japonica, Non-management-Rugged area-Eurya japonica. As the result of vegetation structure, Pinus thunbergii dominated in canopy layer and Camellia japonica and Eurya japonica dominated in Type I and in Type II and III, respectively. Especially, Machilus thunbergii as the climax species in the warm temperate forest were distributed centering shrubs, and as the result of distribution of diameter of breast height, middle size of Celtis sinensis and Machilus thunbergii were distributed in type I, II. Machilus thunbergii were distributed in range of 4 to 44 individuals through the all types. Mean age of canopy layer was 66 year-old and sub-canopy layer was 22.9 year-old. Shanon's species diversity was analysed from 0.5472 to 0.8646. As the vegetation management direction of Dongbaek island, managed Camellia japonica forest was suggested to maintain the regular management and non-managed Eurya japonica forest was required to remove the Eurya japonica and plant the Camellia japonica. In case of non managed Eurya japonica forest in rugged area, vegetation succession was required to laurel forest.

• Journal of Life Science
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• v.25 no.1
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• pp.37-43
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• 2015

We have investigated the effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), indole-3-acetic acid (IAA) and methyl jasmonate (MeJA) on the development of aerenchyma in the primary root of maize (Zea mays). Because plant hormones affected the longitudinal organization of the primary root, we need an indicator to direct the positions for comparison between control and hormone-treated roots. Therefore, the zones of the maize primary root were categorized as PR25, PR50 and PR75, where each value indicates the relative position between the root tip (PR0) and the base (PR100). Aerenchyma was not observed at PR25 and PR50 and rarely found at PR75 in the cortex of control roots. The aerenchymal area at PR75 increased in the presence of the ethylene precursor ACC or a natural auxin IAA. On the other hand, MeJA differentially acted on non-submerged and submerged roots. Exogenously applied MeJA suppressed the aerenchyma formation in non-submerged roots. When the primary root was submerged, aerenchymal area expanded prominently. The submergence-induced aerenchyma formation was amplified with MeJA. Lateral root primordia have been known to inhibit aerenchymal death of surrounding cells. All the three hormones stimulating aerenchyma formation as described above did not restore the inhibition caused by lateral root primordia, suggesting that the inhibitory step regulated by lateral root primordia can be located after hormonal signaling steps.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.55-62
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• 2020

Chironomidae widely utilize as a biological indicator that has various types of feeding pattern such as omnivorous, herbivorous and carnivorous. Polypedilum scalaenum is known as omnivorous, it plays an important role in the food chain of freshwater ecosystems in Korea. Nevertheless, detailed information about diet items of P. scalaenum is still lacking. The purpose of this study is to identify the gut and intestine contents of items on P. scalaenum inhabiting the large-scale weirs of the four major river ecosystems(Ipoh Weir, Sejong Weir, Juksan Weir, Gangjeong-Goryeong Weir, and Dalseong Weir). Phytoplankton was dominant diet items among the study sites. However, zooplankton (i.e. appendages, setae) only found in Ipoh Weir. The phytoplankton species composition in the study sites was correspond to the diet items in the gut and intestine contents of P. scalaenum. In summary, analysis of P. scalaenum gut and intestine contents in this study was able to identify the feeding characteristics of omnivorous Chironomidae, and in particular, it was possible to study the species composition of basic producers in the surrounding aquatic environment by analyzing the contents of the digestive tracts.

• Research in Plant Disease
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• v.11 no.2
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• pp.208-212
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• 2005

At the survey of June, 2002, total 294 dead frees were found in 20 ha of Black pine (Pinus thunbergii) forest located in the western coastal region of Korean peninsula. The dead trees were scattered over the 27 place as groups of about ten trees each. As a result of the field survey on the relationship between the conditions of dead trees and the occurrence of fruiting bodies of Rhizina undulata around the dead and/or dying trees, from June 2002 to August 2004 in the four plots, the occurrence of infected trees was observed as a shape of an irregular concentric circle from the first infected tree and R. undulata was found mainly around the dead tree. Because there was no observation of any other insects and pathogens which would kill trees, the cause of tree death in groups was considered owing to R. undulata. From the analysis of the physical and chemical proper ties of the soil collected from the damaged areas, the pH of soil was between 4.6 and 5.8 and the contents of soil nutrients were very low. Any "fire" trace was not found at all the 27 damaged places in the area, Taean, Chungcheongnam-Do, which are generally known as an important factor to initiate development of the disease. Therefore, further examination is needed to verify precisely about other environmental factors related with the group dying of the Black pines in this area beside 'fire'.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1145-1148
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• 2007

한국을 비롯하여 논농사 중심지역에서는 하천 주변이 과거에는 농경지로, 그리고 오늘날은 도시지역으로 개발되어 하천의 원형이 거의 유지되지 못하고 있다. 하천은 수역과 수변으로부터 거리에 따라 여러 개의 이질적 생태적 공간이 이어지는 복합생태계로서 하나의 경관으로 볼 수 있다. 하천이 하나의 온전한 생태적 계로서 기능을 발휘하기 위해서는 이들을 모두 포함하는 하천의 원형이 복원되어야 한다. 현존하는 하천복원사업이 수변 구역의 복원에 초점을 맞추고 있지만, 진정한 복원이 이루어지기 위해서는 온전한 강변 식생의 복원이 선결과제이다. 본 연구에서는 유적군락의 형태로 잔존하는 강변 식생을 조사하여 식생복원 모델로 삼고자 한다. 수위와 침수체제에 의해 하천의 횡단구조를 수변, 홍수터 및 제방으로 구분한 후 각 지소의 적합한 식생단위를 구분하여 생태적 복원을 실현하기 위한 정보를 구축하였다. 수변식생으로는 달뿌리풀군락과 갈대군락이 자주 출현하고, 홍수터에는 갯버들군락과 키버들군락이 우세하였다. 그 중 전자의 식물군락은 하상재료가 거친 입자의 지소에 성립하고, 후자의 것은 미세한 입자의 지소에 성립하는 경향이었다. 제방역에는 버드나무군락, 다릅나무군락, 귀룽나무군락, 물푸레나무군락, 산사나무군락, 신나무군락(한탄강 지류), 참느릅나무군락, 물푸레나무-갈참나무군락(한탄강 본류), 오리나무군락(민통선 북방지역), 소나무군락, 황철나무군락, 느릅나무군락(소양강 상류), 왕버들군락(금강 중류) 등이 성립하였다. 이러한 식생정보를 하천의 지리적인 위치에 따라 구분하였고, 생태적 복원 시 도입식물을 결정하기 위한 자료로 삼기 위해 각 식생단위를 이루는 종 조성을 정보 체계화하였다.을 효율적으로 하기 위하여 Solar Unit으로부터 나오는 전기를 중전기에서 밧데리로 축전을 시키고 완전 충전 후에는 나머지 전기는 방전이 되도록 회로를 구성하였다. 사통수문 자원조사 결과에 의하면 현재 저수지에 물공급을 하는 수문은 취수탑 형식이 70% 이상을 차지하고 있으며 나머지 30%의 사통수문 중 원형수문비가 98% 이상을 차지하고 있다. 현재 대체에너지를 사용하는 저수지 사통수문은 없는 것으로 조사되었으며 전력을 사용하는 사통도 조사결과에 의하면 20% 이내로 나타났다. 이러한 결과는 향후 수리시설 개보수시 적은 예산으로 사업을 시행하는 경우 사통수문의 설치방향의 지표가 될 것으로 판단되며 수리시설의 운영관리에 대한 새로운 대안으로 제시할 수 있다.분류되었다. 지표 유거가 많아 배수등급이 매우양호로 분류되던 토양은 정 등(1995)의 분류와 비교하여 대부분 강우 유출 가능성이 큰 쪽으로 조정되었다. 새로운 수문학적 토양유형을 이용할 경우 낮은 토심에서 암반층이 발견되는 산림토양이 분포한 유역이나 산림, 밭 등에 식질 토양이 많이 분포하는 유역에서는 기존의 방법을 이용하는 것보다 강우 유출량이 높게 평가될 것으로 판단된다. 앞으로 강우 유출량 실측자료와의 비교를 통해 지속적인 보정을 하여야 할 것이며 특히 불투수층의 존재시 일괄적으로 D유형으로 분류된 토양의 경우 깊이에 따라 C 또는 D 유형으로 세분하여 조정할 필요가 있다.가 있었다. 에틸아세테이트분회물의 경우 디글로로메탄 분회물에 비해 다소 낮은 저해효과를 나타내었지만 250 ${\mu}$g/ml 농도에서 약 60%의 세포독성 효과를 나타내었다. 디클로로메탄 분획물과 에틸아세테이트 분