• 한국응용곤충학회지
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• 제16권4호
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• pp.209-210
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• 1977

Early in the growing season of 1976, rain and cool weather favored the blighting of leaves of young plants of barley by Fusarium nivale. The fungus was recovered in culture from infected foliage, and the perithecia of Calonectria nivalis were demonstrated to be present as well as the Fusarium state. On 22 April 1976, in Suweon, plants pulled at random revealed stem lesions from which F. nivale was cultured. On S May 1976 near Kwangju. Perithecia were found embedded within leaf sheaths and blades of mature wheat and barley plants. It was evident in the 1976, 1977 season that Fusarium(Calonectria) nivale was common but unrecognized as an early season pathogen of barley in Korea. The probable source of primary inoculum was the infected refuse from the previous season's barlry and wheat crops. Stem lesions caused by this fungus were considered to he detrimental to the maximum yield of barley or wheat.

• 식물병연구
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• 제10권4호
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• pp.227-230
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• 2004

Occurrence and epidemiology of crown gall caused by A. tumefaciens in persimmon tree was investigated. Persimmon tree was more sensitive to crown gall disease than peach and jujube tree. Over 80% persimmon trees were infected to crown gall in all investigated region with no relation to planted years. Yield of infected tree was severely decreased to 54%. Incidence of crown gall in nursery field of persimmon tree was also severe and the infection rate of persimmon seedlings collected from market was 34%. It was guessed that the primary inoculum of crown gall caused by A. tumefaciens is infected persimmon seedlings.

• 한국균학회지
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• 제8권1호
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• pp.53-57
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• 1980

An undescribed black root rot of soybean, caused by Cylindrocladium crotalariae, was observed in Suweon area. The diseased plants showed yellowing at the top and dry rot at the root. Lesions of roots and stems in the soil were red to brown and main roots were cracked. Although not observed the disease in the field, leaves of inoculated test plants in the greenhouse exhibited circular, brown lesion surrounded by chloratic halos. The fungus was recovered in culture from the infected stem and root, and the perithecia of Calonectria crotalariae were demonstrated to be present as well as the cylindrocladium state. The fungus was pathogenic to the root, stem, petioles and leaves of soybean. The probable source of primary inoculum was microsclerotia formed in infected soybean root and stem from the previous season's soybean debris. Black root rot by this fungus was considered to be one of detrimental factors to the maximum yield of soybean. From the morphological and physiological characteristics and pathogenic behaviors, this fungus was identified as Cylindrocladium(Calonectria) crotalariae.

• 한국응용곤충학회지
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• 제23권1호
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• pp.22-27
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• 1984

오이를 재배했던 비닐하우스 토양에 병원균을 전면 접종하고 1983년 7월 25일부터 8월 25일까지 포리에칠렌 필림을 멀칭하여 태양열소독 효과를 실험하였다. 멀칭처리 기간중 토양의 일중 최고온도는 깊이 5cm에서 $58^{\circ}C$, 15cm는 $45^{\circ}C$, 25cm는 $42^{\circ}C$에 달했다. 태양열처리 한지 32일 경과후 지표로부터 5cm이내의 토양에 있던 병균은 완전히 사멸되었으며 15cm 까지는 $98\%$ 이상 소멸되었으나 25cm 토양은 무처리와 차이가 없었다. 그러나 태양열처리한 토양에서 분리한 균주는 무처리 토양의 균주보다 소형포자 생산량이 현저하게 감소되었다. 멀칭처리에 재배한 오이는 생육이 월등히 좋았는데 특히 5cm 이내의 토양에서 두드러지게 나타났으며 노지재배의 경우도 생장과 수량이 무처리에 비하여 현저히 좋았다. 병원균 F. oxysporum f. sp. cucumerinum은 오이 유균에 외관상 나타나는 병징 이외에도 전염원의 농도가 증가됨에 따라 오이 생육이 비례하여 억제됨을 나타내었다.

• 식물병연구
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• 제12권3호
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• pp.221-225
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• 2006

용담에서 전형적인 모자이크 증상을 나타낸 바이러스 이병주 및 황화증상을 보이는 식물체를 채집하였다. 이들 중, 모자이크 증상의 잎을 접종하여 전신감염된 Nicotiana benthamiana로부터의 접종원을 동부의 초생엽에 접종하였을 때, 2가지 형태의 괴사 국부병반이 형성되었다. 즉 하나는 작은 크기 pinpoint 형태의 국부 괴사병반(SNS)이며, 다른 하나는 SNS보다 약간 큰 halo 형의 국부 괴사 병반(LNS)으로 뚜렷하게 구분되었다. 한편 황화 병징의 용담으로부터 증식된 접종원은 동부의 초생엽에 LNS만 형성하였다. 동부에 형성된 SNS 및 LNS형 병반을 각각 단일병반 분리하여 N. bentamiana에 접종하였다. 그 결과 SNS를 접종한 N. bentamiana에서는 접종엽에 무병징, 상위엽에는 전형적인 모자이크 증상이 발현되었다. 반면 LNS를 접종한 식물체에서는 접종엽에 퇴록 윤문이 형성되었으며, 상위엽에는 괴저를 동반한 모자이크 증상이 발현되었다. 이들 SNS 및 LNS 병반으로부터 분리한 바이러스를 dsRNA, RT-PCR 및 혈청학적 유연관계 분석을 통하여 SNS 병반은 CMV에 의해서, LNS는 BBWV2에 의해서 유도된다는 것을 확인하였다. 이 연구의 결과로부터 자연계에서 CMV와 BBWV2가 복합감염되어 병징의 구분이 어려운 경우, 동부에 접종하여 유도된 병반을 이용하여 두 바이러스의 감염을 쉽게 구분할 수 있는 방법으로 활용할 수 있을 것으로 생각되었다.

• 한국균학회지
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• 제10권2호
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• pp.85-88
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• 1982

맥류(麥類) 붉은곰팡이병(病)의 제(第)1차(次) 전염원(傳染源)인 자낭포자(子囊胞子)의 비산상황(飛散狀況)을 조사(調査)하여 본병(本病)의 발생(發生)을 사전(事前)에 예찰(豫察)코져 3개(個) 지역(地域)에서 2개년간(個年間) 시험(試驗)하여 다음과 같은 결과(結果)를 얻었다. 1) 맥류병(麥類病) 예찰포장(豫察圃場)에 회전식(廻轉式) 포자채집기(胞子採集器)를 설치(設置)하여 매일(每日) 자낭포자(子囊胞子)의 비산상황(飛散狀況)을 조사(調査)한 결과(結果) 그 자낭포자(子囊胞子)의 비산(飛散)은 4월(月) 초순(初旬)부터 시작(始作)되며 그 비산(飛散) 포자(胞子)의 수(數)는 지역(地域)에 따라 달라 중부(中部)인 수원(水原)보다 남부(南部) 답리작(畓裏作) 지대(地帶)인 광주(光州) 나주(羅州)에서 많았다. 2) 1979년(年)과 1980년(年) 공(共)히 강우량(降雨量)이 많은 경우(傾遇) 자낭포자(子囊胞子)의 비산수(飛散數)도 많은 경향(傾向)이었다. 3) 맥류(麥類) 붉은곰팡이병(病)의 1차(次) 전염원(傳染源)인 자낭포자(子囊胞子) 비산량(飛散量)과 강우량(降雨量)은 고도(高度)의 정(正)의 상관관계(相關關係)임을 보여주었다. 4) 3개(個) 지역(地域)인 수원(水原) 광주(光州) 나주(羅州)에서의 2년간(年間) 조사결과(調査結果)로 본(本) 병(病)에 대(對)한 과학적(科學的) 예찰(豫察)이 가능(可能)하게 되었으며 이를 전국적(全國的)으로 확대(擴大) 실시(實施)하여 맥류(麥類) 증산(增産)에 기여(寄與)할 것이다.

• Journal of Ginseng Research
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• 제28권3호
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• pp.149-156
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• 2004

The objectives of this study were to investigate the morphology of mycorrhizal roots, and the effects of root age and soil texture on the mycorrhizal infection in ginseng (Panax ginseng C. A. Meyer) growing in Korea. Ginseng roots at ages of two to six years were collected from fields in late June. Their infection by arbuscular mycorrhizal fungi(AMF) was studied by clearing the roots and staining fungal hyphae with trypan blue. Root infection varied greatly depending on the developmental stages of young roots. Young tertiary roots, in diameter of smaller than 0.8 mrn, formed during the current growing season had root hairs and were frequently and in some cases heavily infected by AMF. Hyphal coils and arbuscules were abundant, while vesicles were rarely observed. Older secondary or tertiary roots in diameter of bigger than 1.0 mm with fully differentiated primary xylem formed during the previous growing season had no root hairs, and were not infected at all. The rates of mycorrhizal infection in the young tertiary roots were not affected by the age of the ginseng plants, suggesting that fungal populations might have not much changed during the aging of the cultivated fields up to six years. The differences in the infection rates among the different ages of ginseng were caused by differences in the amount of young tertiary roots in the samples. Soil texture, either sandy loam or clay loam, did not affect the rate of root infection. There were large variations in the infection rates among the different farms and locations within a farm. It strongly suggested that infection rates of the ginseng roots by AMF would be influenced by the practice of the farmers, possibly by avoiding consecutive planting, introduction of new topsoil, and the ways of handling the soil before transplanting the ginseng, such as fumigation or sterilization that might have affected indigenous inoculum sources of the AMF.

• 환경생물
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• 제29권4호
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• pp.265-273
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• 2011

Bacterial diversity based on the denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA gene sequences was determined for soil samples from two abandoned mine sites and the corresponding enrichment cultures using soil sample as key inoculum. Sequencing analysis of DGGE bands obtained from both the soil samples matched mostly with sequences of uncultured and newly described organisms, or organisms recently associated with the acid mine drainage environment. However, the enrichment of soil samples in ferrous sulfate and elemental sulfur media yielded sequences that were consistent with well-known iron- and sulfur-oxidizing acidophilic bacteria. Analysis of enrichment cultures of soil samples from Dalsung mine revealed abundant ${\gamma}$-$Proteobacteria$, whereas that of Gubong mine sample displayed acidophilic groups of ${\gamma}$-$Proteobacteria$, ${\alpha}$-$Proteobacteria$, $Actinobacteria$ and $Firmicutes$. Chemical elemental analysis of the mine samples indicated that the Dalsung site contained more iron and sulfate along with other toxic components as compared with those of the Gubong site. Biogeochemistry was believed to be the primary control on the acidophilic bacterial group in the enrichment samples.

• The Plant Pathology Journal
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• 제20권4호
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• pp.289-292
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• 2004

The population of Ralstonia solanacearum (Rs) in soil is very important as a primary inoculum source of bacterial wilt in tobacco fields. To investigate the population of Rs, physical properties and chemical components during the tobacco growing season, soil samples were taken from the fifteen fields which were located in the flue-cured tobacco growing area, Ansung, Kyunggi province and Wonju, Kangwon province. Two fields of the fifteen were bacterial wilt free. Six fields had less than 10% plants being diseased and seven over 10%. The Rs population level determined by using SMSA medium generally showed an up-and-down pattern being low in May, high in Jun and July and low in August. The soil population in May and June showed a positive correlation with the incidence of bacterial wilt (r=0.571$^*$, r=0.688$^{**}$), but P$_2O_5$, content of soil was negatively correlated with the disease incidence (r=-0.539$^*$). These results suggest that Rs population in soil examined in May or in June, and the P$_2O_5$ content in soil should be key factors to determine the bacterial wilt potential of tobacco fields.

• 한국응용곤충학회지
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• 제10권1호
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• pp.39-41
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• 1971

사과 탄저병은 매년 특정기간의 과실에 한하여 발병한다는 것으로 미루어 보아 지간에서 자낭각의 형으로 월동하는 것으로 보고 연구한 결과는 다음과 같다. 1) 사과, 포도, 아까시아 등의 공시나무가지에 병균이 감염되어서 포자퇴가 형성되는 것으로 보아 본 병균은 나무가지에서 월동이 가능한 것으로 생각된다. 우리나라에서는 발견하지 못했던 자낭세대가 접종된 공시나무가지의 병환부의 껍질속과 병과의 표피밑에서 검출되었으므로 자낭각의 형으로 지간에서 월동하여 일차전염원이 될 수 있다는 사실을 알았다.