• 식물병연구
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• 제27권4호
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• pp.187-191
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• 2021

Wilt symptoms were frequently observed in Korean blackberry (Rubus coreanus) plants grown in farmers' fields located in Gochang and Jeongeup, Jeonbuk Province, Korea during disease surveys in July 2020. The disease occurred in 10 of the 13 fields surveyed in the two locations. The incidence of diseased plants in the fields was 5-80%. Seven isolates of Fusarium sp. were obtained from the diseased plants and examined for their morphological and molecular characteristics. All the isolates belonged to Fusarium oxysporum species complex based on the morphological characteristics but were identified as F. cugenangense based on the molecular characteristics. Two isolates of F. cugenangense were tested for pathogenicity on Korean blackberry plants by artificial inoculation. Pathogenicity of the two isolates on the plants was confirmed with the inoculation tests, which showed wilt symptoms similar to those observed in the diseased plants in the fields investigated. This is the first report of F. cugenangense causing Fusarium wilt in Korean blackberry.

• The Plant Pathology Journal
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• 제23권1호
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• pp.3-6
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• 2007

Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris(FOC) is the most destructive disease in India. It is seed-borne as well as soil-borne pathogen. The role of seed-borne FOC in introducing and establishing wilt in FOC free soils is unknown. Using seeds of FOC infected chickpea cultivar K 850, we provided an evidence of establishing wilt disease in the FOC free soils within three crop cycles or seasons. In the first cycle, typical wilt symptoms were observed in 24 pots in 41 days after sowing. These 24 pots were used for second and third cycles without changing the soil. These 24 pots were sown with seeds collected from healthy plants of a susceptible cultivar JG 62, one seed per pot and development of wilt symptom was recorded. Wilt symptoms appeared in all the pots 26 days after sowing in second cycle and in 16 days after sowing in third cycle. On selective medium, all of the wilted plants yielded FOC in all the three cycles indicating that the mortality was due to wilt. FOC propagules on selective medium were 172, 1197, and 2280 $g^{-1}$ soil at the end of the first, second, and third cycles, respectively. These studies indicated that Fusarium wilt of chickpea is seed-borne and seeds harvested from wilted plants when mixed with healthy seeds can carry the wilt fungus to new areas and can establish the disease in the soil to economic threshold levels within three seasons.

• The Plant Pathology Journal
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• 제25권3호
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• pp.256-262
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• 2009

The potential of. nonpathogenic Fusarium oxysporum strain Avr5, either alone or in combination with chitosan and Bion, for inducing defense reaction in tomato plants inoculated with F. oxysporum f. sp lycopersici, was studied in vitro and glasshouse conditions. Application Bion at concentration of 5, 50, 100 and $500{\mu}g$/ml, and the highest concentration of chitosan reduced in vitro growth of the pathogen. Nonpathogenic F. oxysporum Avr5 reduced the disease severity of Fusarium wilt of tomato in split plants, significantly. Bion and chitosan applied on tomato seedlings at concentration $100{\mu}g$ a.i./plant; 15, 10 and 5 days before inoculation of pathogen. All treatments significantly reduced disease severity of Fusarium wilt of tomato relative to the infected control. The biggest disease reduction and increasing tomato growth belong to combination of nonpathogenic Fusarium and Bion. Growth rate of shoot and root markedly inhibited in tomato plants in response to tomato Fusarium wilt as compared with healthy control. These results suggest that reduction in disease incidence and promotion in growth parameters in tomato plants inoculated with nonpathogenic Fusarium and sprayed with elicitors could be related to the synergistic and cooperative effect between them, which lead to the induction and regulation of disease resistance. Combination of elicitors and non-pathogenic Fusarium synergistically inhibit the growth of pathogen and provide the first experimental support to the hypothesis that such synergy can contribute to enhanced fungal resistance in tomato. This chemical could provide a new approach for suppression of tomato Fusarium wilt, but its practical use needs further investigation.

• Mycobiology
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• 제51권3호
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• pp.186-194
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• 2023

In July 2021, wilting symptoms were observed in adult and seedling hemp (Cannabis sativa L. cv. Cherry Blossom) plants grown in a greenhouse. As the disease progressed, yellowing and wilting symptoms on the leaves developed, resulting in whole plant death. In seedling plants, typical damping-off symptoms were observed. To identify the pathogen, the roots of diseased plants were sampled, surface sterilized, and cultured on potato dextrose agar (PDA) media. From the culture, 4 different fungal isolates were recovered and purely cultured. Each fungal isolate showed distinct growth shapes and color development on malt extract agar, oatmeal agar, sabouraud dextrose agar, and PDA media. Microscopic observation and molecular identification using ribosomal DNA internal transcribed spacer sequencing identified them as 3 Fusarium spp. and 1 Thielaviopsis paradoxa. Additional sequencing of elongation factor 1-alpha and b-tubulin regions of 3 Fusarium spp. revealed that 2 of them are Fusarium solani, and the other one is Fusarium proliferatum. To examine which isolate can act as a causal agent of wilt disease of hemp, each isolate was tested for their pathogenicity. In the pathogenicity test, F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3, but not T. paradoxa AMCF4, were able to cause wilting disease in hemp seedlings. Therefore, we report that F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3 as causal agents of Fusarium wilt of hemp plants. To our knowledge, this is the first report of the wilt disease of C. sativa L. caused by Fusarium spp. in Korea.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.260-263
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• 2005

This study was carried out to investigate the effects of spatial resolutions on digital image for detecting pine trees damaged by pine wilt disease. Color infrared images taken from PKNU-3 multispectral airborne photographing system with a spatial resolution of 50cm was used as a basic data. Further test images with spatial resolutions of 1m, 2m and 4m were made from the basic data to test the detecting capacity on each spatial resolution. The test was performed with visual interpretation both on mono and stereo modus and compared with field surveying data. It can be conclude that it needs less than 1m spational resolutions or 1m spatial resolutions with stereo pair in order to detect pine trees damaged by pine wilt disease.

• 한국연초학회지
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• 제15권2호
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• pp.137-144
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• 1993

The present study was conducted to compare the efficiency of individual plant selection for resistance to bacterial wilt with 30 dihaploid lines derived by anther culture and Nicotiana africana method in Fl and F2 generation from a cross between Bright Yellow 4 (BY4) and NC95. F2 dihaploid lines were selected from bacterial wilt disease resistant plants screened under the naturally infested filed conditions. The populations of FB - ADH and FB MDH derived from F2 individual plants with bacterial wilt resistance showed higher resistance to the disease than the populations of Fl - ADH and Fl - MDH, respectively, and no difference for the disease resistance appeared by the haploid deriving method within a generation.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제2호
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• pp.192-198
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• 2004

It is increasing scenery created as a result of pine wilt disease. The purpose of this study is to investigate the local resident's awareness against the scenery caused by pine wilt disease in their neighboring area, through the questionnaire investigation. The result showed that more than $40\%$ of the residents are not aware of such scenery in their local area, and about 30% of the residents did not know that those trees were dying. More than $40\%$ of the people do not know of the pine wilt disease as a general argument. Another question showed that the recognition of such scenery depends on the distance of the viewer. General residents don't worry about such scenery in the far distance in fact some of them think those are colored leaves. However, the nearer they see the trees, the higher they have negative feeling against it.

• 한국연초학회지
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• 제30권1호
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• pp.1-7
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• 2008

Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tobacco in Korea. No effective single control measure is available at present time. One of the most potential way for controlling the bacterial wilt on tobacco is growing tobacco cultivars resistant to the bacterial wilt. In this study, optimal conditions for screening tobacco cultivars resistant to the bacterial wilt were examined to provide reproducible and efficient methods in growth chamber testing and field experiments for evaluating plant disease resistance. For this, already-known inoculation methods, inoculum densities, and incubation temperature, and plant growth stages at the time of inoculation were compared using tobacco cultivars resistant (Nicotiana tabacum cv, NC95), moderately resistant (N. tabacum cv. SPG70), and susceptible (N. tabacum BY4) to the bacterial disease. It was determined that root-dipping of tobacco seedlings at six true leaf stage into the bacterial suspension with inoculum level of $10^8$ colony-forming units (CFU)/ml for 20 min before transplanting was simple and most efficient in testing for resistance to the bacterial wilt of tobacco caused by R. solanacearum, for which disease incidences and severities were examined at 2 weeks of plant growth after inoculation at $20{\sim}25^{\circ}C$ in a growth chamber. These experimental conditions could discriminate one tobacco cultivar from the others by disease severity better than any other experimental conditions. In field testing, the optimum time for examining the disease occurrence was late June through early July. These results can be applied to establishing a technical manual for the screening of resistant tobacco cultivars against the bacterial wilt caused by R. solanacearum.

• 디지털콘텐츠학회 논문지
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• 제18권1호
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• pp.191-195
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• 2017

본 연구에서는 우리나라의 대표수종 소나무의 치명적인 해충인 소나무재선충 피해목의 확산을 조기에 차단하고 산림수목에 대한 지속적인 관리를 위하여 소나무재선충 피해수목 신고 어플리케이션을 개발하였다. 어플리케이션은 다음과 같이 3개 핵심항목을 중심으로 개발되었다. 첫째, 소나무재선충에 대한 정보제공, 둘째, 피해목의 자가진단, 셋째, 수목안전지도 등으로 구성하였다. 향후 본 어플리케이션의 활성화를 위해서 실제로 어플리케이션을 사용하는 이용자들의 적극적인 참여와 산림청 어플리케이션과의 통합개발이 이뤄진다면 보다 많은 활용이 가능할 것이다.

• 대한원격탐사학회지
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• 제35권3호
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• pp.359-373
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• 2019

소나무재선충병은 우리나라 소나무림에 심각한 위협이 되고 있는 질병이다. 그러나 일반적으로 재선충병의 고사목 관측은 현장조사를 기반으로 하고 있기 때문에 물리적, 경제적 문제가 있어 대규모 삼림을 관측하는데 어려움이 있다. 본 연구에서는 소나무재선충병이 재발한 지역에 무인 항공기를 이용하여 고해상도 영상을 획득하였다. 이후 Artificial Neural Network(ANN), Support Vector Machine(SVM) 감독분류 기법을 통해 소나무재선충병 의심목을 탐지하였고. 감독분류 결과에 대한 정확도를 산출하였다. 또한 접근성이 높은 산림에 대해 감독분류를 실시한 후 현장 조사 결과간의 비교를 통해 정확도의 신뢰성을 검증하였다.