• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.319-328
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• 2021

Tomato spotted wilt virus (TSWV) is one of the most destructive viruses worldwide, which causes severe damage to economically important crops, such as pepper and tomato. In this study, we examined the molecular and biological characterization of a TSWV isolate (SW-TO2) infecting tomato and compared it to the recently reported isolates from boxthorn, butterbur, and angelica plants. The phylogenetic analysis based on the complete genome sequences confirmed that SW-TO2 was clustered with those of isolates from boxthorn and pepper in Korea with the maximum nucleotide identities ranging from 98% to 99%. We developed the bioassay method for screening TSWV resistance and tested some commercial pepper and tomato cultivars for resistance evaluation of four isolates of TSWV. TSWV resistance was evaluated as TSWV resistance when all the following three conditions were satisfied: first, when symptoms of necrotic spots or no symptoms were present in the inoculated leaves; second, when there were no symptoms in the upper leaves; and third, when the upper leaves were negative as a result of RT-PCR diagnosis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.165-170
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• 1981

Recently an unknown microbial desease and some parasitic crustaceans are prevailing in the sea-weed farms of Uudaria pinnatifida along the south-eastern coast of Korea.(1) Green spots probably caused by the microbial pathogens were found on the fronds of Undaira Pinnatifide. Particularly they were densely distributed on the distal half of the fronds. The tissues of the green spot area rot off, and small holes with green colored margin are formed. The holes at the distal part of the fronds are enlarged and they finally coalesced each other. Then this process accelerates decaying of the distal ends of the fronds.. The fronds growing in the central part of the farms are usually severely damaged, whereas in the marginal area of the farm toward the open sea side the damage is less serious. An examination revealed that the deseased fronds bore a number of viable bacteria, $6.8\times10^5\;to\;1.2\times10^6$ per gram at $15^{\circ}C$, whereas the healthy fronds $1.1\times10^4$. Twenty-six kinds of colonies, 247 strains of bacteria, were isolated from deseased fronds, belonging to Moraxella, Achromobacter, Vibrio, Flavobacterium, Acinetobacter, Pseudomonas, etc. (2) Pinholes occurred in one series on the frond. They were probably caused by a harpacticoid copepod, Thalestris sp. Seven years ago when the disease was first found to occur the copepod was observed on the fronds from March of the year. Recently, however, they have been found as early as December of the previous year. (3) A gammarid amphipod, Ceinina iaponica, invades the pith of the midrib through holdfast of thalli. This rarely causes the longitudinal seperation of the entire frond through the midrib as they bore a tunnel in the pith. Sometimes holdfasts of tile heavy damaged thalli make the frond departed from the substrate.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.282-288
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• 1995

To investigate the alterations in the ultrastructure of leaves by acid rain, 10mm of SAR(Simulated Acid Rain, pH 2.0, 2.7, 3.0, 6.0) was applied to three crops(red-pepper, perilla, eggplant) at a two-day interval. The symptoms of leaf damage by SAR were observed by naked eyes and SEM(Scanning Electron Microscope), and the peroxidase activity in the leaves was measured. The results are summarized as follows : The severity of SAR damages to the crops observed by naked eye were in the decreasing order of red-pepper, perilla, and eggplant. The Symptoms were characterized by brown or white spots on the leaf surface. In the SAR treatment of pH 3.0, trichomes of all crops except for eggplant were damaged. By the SAR treatment of pH 2.7, stomata were damaged in all crops. With one time treatment of SAR, the peroxidase activity of perilla was rapidly increased.

• Korean Journal of Environmental Agriculture
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• v.1 no.2
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• pp.99-104
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• 1982

These studies were carried out to investigate the damage of root rot of hop by heptachlor residues in soil at nine farm fields and pot experiment for two years from 1980 to 1981. 1) Pot experiment results indicated that root rot of hop occurred in farm field were caused by heptachlor phytotoxicity. 2) The damage of root rot of the hop was found by heptachlor residues in soil. Hop root in the low concentration of heptachlor was turned to brown mottle, and then rotted. In high concentration, the hop root was decreased in number, blocked in growth, and resulted to greyish change with death. 3) Hop vine damaged by heptachlor was hardened and broken with ease. 4) Heptachlor epoxide which was inferred to be the main cause of hop root rot gave the damage to hop at 0.009 ppm reisdues in soil. 5) The phytotoxicity of heptachlor was proved to last for 10 years or more in this study.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.167-174
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• 2000

A glass chamber experiment was conducted to evaluate the impact of ozone (O$_3$) on the physiology of two soybean, Glycine max L. cultivars, 'Hwanggum' and 'Jangyub'. Thirty-day old plants with 1-2 nodes were exposed to $O_3$ of <10 and 150 n1 1$^{-1}$ in the chambers for 8 h d$^{-1}$ for 3 days. Net photosynthesis, stomatal conductance, chlorophyll a, chlorophyll b and total chlorophyll contents, and foliar injury (% injured leaves) were measured. Although foliar damage was more severe on Jangyub than on Hwanggum, net photosynthesis was decreased by 60% on Hwanggum and 13% on Jangyub due to the $O_3$ treatment. Stomatal conductance on Jangyub was twice higher than that on Hwanggum and it was not changed by the $O_3$ treatment. Whereas, stomatal conductance on Hwanggum was 60-80% decreased by $O_3$, Chlorophyll contents did not change due to the $O_3$ treatment or variety. We can conclude that the reduction of net photosynthesis by $O_3$ was mainly due to the decreases of stomatal conductance and Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) activity on dark reaction. And foliar injury and chlorophyll content did not contribute to the net photosynthetic decrease. The gas-exchange variables measured 24 h after the termination of $O_3$ fumigation showed that there was no significant recovery within a day. Since the physiological responses on Jangyub were not much affected by the $O_3$ treatment, this variety could be $O_3$ resistant.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.3
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• pp.75-81
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• 2008

This study was conducted to analyze the influence of simulated acid rain on leaves of Liliodendron tulipifera seedlings. The seedlings were treated with four levels of simulated acid rain with pH of 5.6, 4.9, 3.9 and 2.9, and then chlorophyll contents and the degree of foliar damage were investigated. Differences were statistically significant among treatments in chlorophyll contents in all of the tested soils. The total contents of chlorophyll tended to decrease as the simulated acid rain treatment was maintained. Chlorophyll contents, however, did not decrease according to the decrement of pH levels. Foliar damage increased as the simulated acid rain was maintained in all tested soils. Especially, the damage dramatically increased between May and July as the acidity increased. As the treatment of simulated acid rain continued, deformed new leaves appeared. In all treatments except the control, the leaves turned brown and the damage increased with time. Necrotic spots appeared during the first month of treatment at the pH level of 2.9 in all soil types. The damage by acid rain should be considered when we plant Liliodendron tulipifera.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.6 no.11
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• pp.2-11
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• 1985

과수농사를 짓는데 있어서 어느 해이던 간에 병해충의 발생이 없는 해는 없다. 올해 역시 예년과 마찬가지로 각종 병해충이 발생되었던 한해였다. ''70년도부터 ''85년도까지의 주요 병해충 발생양상을 보면, 점차 증가하고 있는 병해로 사과반점낙엽병과 부패병이 있는데, 이들 병은 ''70년대초에는 거의 무시할 정도의 발생을 보인 병들로 ''78년이후 급증하는 병이며, 해충은 점박이응애, 사과굴나방, 조팝나무진딧물, 포도호랑하늘소 같은 것들로 이들 해충은 현재 농약만으로의 방제가 어려운 상태에 있다. 이와는 반대로 점차 그 발생이 감소하고 있는 병해충은 ''70년초 심하였던 배나무적성병, 복숭아축엽병으로 ''75$\~$''80년도에 와서 거의 미미한 발생을 보이고 있다. 반면 예나 지금이나 지속적인 발생으로 과수재배농가에 피해를 주고 있는 것으로 사과부란병, 복숭아세균성천공병, 심식충류, 잎말이나방류, 깍지벌레류 등이 있다. 이들중 올해 가장 문제가 되었던 것은 사과탄저병으로 금년도의 기상조건이 발병에 좋은 조건이었고, 방제시기에 일기가 불순하여 충실한 방제를 하지 못한 관계로 더욱 심하였다.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.13 no.3 s.108
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• pp.98-105
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• 1992

고추에 발생하는 병해는 우리나라에 18여종이 있다. 그중에서 가장 중요한 병해는 두말할 나위없이 역병과 탄저병일 것이다. 세균성점무늬병(반점세균병)과 바이러스병(모자이크병, 괴저병)도 문제가 되고 있으나 앞의 두 병해에 비하면 발생도 국부적이고 피해도 훨씬 가볍다고 할 수 있다. 이 네가지 병해는 우리나라 고추 주산단지의 연작 장해현상과 밀접한 관련을 가지며 연작에 의하여 발병이 심화되는 대표적인 병해다. 이밖에도 고추에는 잿빛곰팡이병, 균핵병, 흰가루병등의 공기전염성 병해들이 시설재배지의 특수환경과 관련하여 점차 발생이 늘어나는 추세에 있다. 여기에서는 고추에서 가장 문제가 되고 있고 농민들이 방제에 큰 어려움을 겪고 있는 역병과 탄저병에 대하여 그 효과적인 방제대책을 알아본다.

• Research in Plant Disease
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• v.22 no.3
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• pp.213-216
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• 2016

Tomato spotted wilt virus (TSWV) is one of the most destructive viruses in tomato plant. TSWV-GT from the leaves of tomato plant showing top wilt symptom in 2015 was used to screen the tolerance in tomato cultivars. Among 51 cultivars commercially available in Korea, 'TY Smartsama' and 'Marnolia' showed tolerance to the virus in bioassay. Three cvs. 'Titichal', 'TY Sensq', and 'Venekia' were moderate tolerance.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.889-894
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• 2005

This experiment was carried out to investigate the effects of simulated acid rain (SAR) in the shoot growth and internal structure of Arabidopsis thaliana. In the shoot growth, the plants treated with SAR (pH 3.0) for 15 days showed no morphological change compared to the control plants. Some change was observed in the internal structure of the stems: the epidermis and cortex tissues of the stems treated with SAR were partly damaged. The plants treated with SAR showed no noticeable difference compared to the control plants, but morphological changes were observed in the leaf. The leaves of the plants treated with SAR showed many white necrotic spots on the part of upper epidermis. A light microscopic examination of the leaves with necrotic spots showed that the upper epidermis was severely compressed with the damaged cuticle layer and the mesophyll cells were also damaged and compressed. However, noticeable structural change of vascular bundle cells was not observed.