• The Plant Pathology Journal
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• 제18권5호
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• pp.231-236
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• 2002

Bemisia tabaci Genn. is an important pest worldwide because of its ability to cause damage by direct feeding and its role as a vector of some viruses including geminiviruses. The first report of Tobacco leaf curl virus (TLCV), a Geminiviruses, in Indonesia was in 1932 when the virus was found infecting tobacco plants in Central Java. The characteristic symptoms of TLCV included upward curling of the leaf edge, vein thickening, and sometimes the occurrence of enation on the underside of the leaves. Basic studies were carried out to elucidate the characteristics of TLCV transmission by its vector, B. tabaci. A single whitefly was able to transmit the virus and the efficiency of transmission was increased when the number of adult whiteflies was increased up to 20 per plant. Inoculation access period of 1 h could cause transmission up to 20% and the optimum inoculation access period was 12 h. Acquisition access period of 30 minutes resulted in 70% transmission while 1(10% transmission occurred with a 24-h acqui-sition access period. The virus was proven to be persistently but not transovarially transmitted. Discrete fragments of 1.6 kb were observed when polymerase chain reaction method was applied to detect the virus in viruliferous nymphs and individual adults of B. tabaci, while no bands were obtained from non-viruliferous nymphs and adults.

• 농약과학회지
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• 제18권3호
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• pp.196-201
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• 2014

본 연구는 참외 담배가루이의 경제적 피해수준과 요방제 수준을 설정하기 위하여 수행하였다. 참외 접목묘는 비닐하우스 내에서 2010년 6월 8일에 정식하였고, 담배가루이 성충을 7월 14일에 1, 5, 10, 20마리/10엽 밀도로 각각 접종하였다. 접종 60일 후 담배가루이 성충 밀도는 20마리 접종 처리구의 경우 초기 접종밀도보다 24.9배 증가하였다. 담배가루이에 의한 잎과 과실의 피해는 접종 후 20일째부터 나타나기 시작하였고, 접종 60일째에 피해엽율과 피해과율은 각각 28.5%와 31.5%였다. 담배가루이 접종밀도와 피해과율과의 관계를 회귀식을 이용하여 분석한 결과, Y = 0.961X + 0.0562($R^2$= 0.976)의 관계식을 얻을 수 있었다. 이 식에 따라 계산된 참외 담배가루이의 경제적 피해수준은 5.1마리/엽, 요방제 수준은 경제적 피해수준의 80%인 4.1마리/엽이었다.

• 한국토양비료학회지
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• 제51권1호
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• pp.28-34
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• 2018

Yuzu (Citrus junos) gummosis disease, caused by Phytophthora nicotianae, was first reported in 1997. As known in citrus, Phytophthora is the most fastidious soil-borne pathogen to control. In order to minimize its damage to Citrus spp., integrated pest management (IPM) approach, including fungicide chemicals and resistant cultivars, is necessary. Therefore, in this study we tried to evaluate tolerance of yuzu cultivars and its related species against yuzu Phytophthora. Trifoliate orange was evaluated as a susceptible host to yuzu Phytophthora by both mycelial growth onto extract media and immature fruit inoculation. However, in zoospores spray-inoculation on 2-year-old cuttings tree, trifoliate orange appeared to have a resistant property as showing less than 6% diseased leaf rate. Among yuzu cultivars only 'Namhae No. 1' appeared resistant property against both P. nicotianae and P. citrophthora. The 'Namhae No. 1' showed 5.7% and 10.6% diseased leaf ratio by P. nicotianae and P. citrophthora, respectively. Clearly, in order to reduce damages caused by two yuzu Phytophthora, we suggest that growers may utilize a trifoliate orange as a rootstock and 'Namhae No. 1' as a scion for fruit production.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권2호
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• pp.255-259
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• 2004

Post-infectional biochemical changes due to Xanthomonas campestris pv. mori (Xcm) infection in five elite mulberry varieties viz., $S_1$, $S_{1635}$, $V_1$, RF $S_{175}$ and JRH was studied under inoculated condition. It was revealed that total soluble sugar and protein content was significantly declined in all the varieties due to X. campestris infection. Total phenol content was at par prior to inoculation in all varieties, but it was significantly increased in $S_1$, RF $S_{175}$, $S_{1635}$ and JRH 7 days after inoculation. The correlation coefficient (r) between total soluble sugar and total phenol content was found positive (r = 0.825) and statistically significant. Similarly, correlation coefficient (r) between total soluble protein and phenol content was found positive (r = 0.897) and statistically significant. The present study indicates that X. campestris infected leaves are nutritionally inferior in quality and the duration of phenol production in a mulberry variety play decisive role on disease resistance.nce.

• 한국환경농학회지
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• 제22권4호
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• pp.255-260
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• 2003

토양에 시용한 규산의 참외 흰가루병에 대한 직접적인 억제 효과와 살균제의 방제 효과를 증진시킬 수 있는 보조효과를 조사하였다. 규산질 비료의 처리는 흰가루병 균에 의해 감염된 참외 잎에서 균사의 생장과 분생포자의 형성을 억제함으로써 흰가루병 발생을 일부 억제할 수 있는 것으로 조사되었다. 물론 규산질 비료 자체만의 흰가루병 발생 억제 효과는 매우 미약한 수준이었으나 살균제의 흰가루병 방제 효과를 크게 증진시켜줄 수 있는 것으로 나타났다. 따라서 현재 농가 현장에서 밝혀지고 있는 규산질 비료의 참외 병해 발생 억제 효과는 주로 이러한 살균제의 효과를 증진시킬 수 있는 규산의 보조적인 작용에 기인하는 것으로 판단된다. 따라서 토양에 대한 적절한 수준의 규산질 비료의 시용은 살균제의 방제 효과 증진을 통하여 과다한 약제의 사용과 그에 따른 부작용을 경감시킬 수 있을 것으로 보인다. 규산질 비료의 흰가루병 발생 억제 효과를 증진시키기 위해서는 앞으로 병의 발생을 최대로 억제할 수 있는 참외 잎 중의 적정 규소 함량에 대한 검토 등의 추가적인 연구가 필요 할 것이다.

• 식물병연구
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• 제29권4호
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• pp.377-383
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• 2023

In 2020 and 2021, we surveyed diseases of three-leaf ladybell (Adenophora triphylla) plants grown in fields at two locations in Korea. During the disease surveys, severe leaf rot symptoms were observed on the young plants in Hongseong, and stem rot symptoms on the adult plants in Cheolwon. The incidence of leaf rot was 5-60%, and that of stem rot 1-10%. We obtained 6 fungal isolates each from the leaf rot lesions and the stem rot lesions. All the isolates were morphologically identified as Rhizoctonia solani. Anastomosis test and investigation of cultural features of the fungal isolates revealed that the isolates from the leaf rot lesions corresponded to R. solani AG-1(IB), and those from the stem rot lesions to R. solani AG-2-2(IIIB). Two isolates each of R. solani AG-1(IB) and AG-2-2(IIIB) were used for DNA sequence analysis and pathogenicity test to three-leaf ladybell plants through artificial inoculation. The anastomosis groups and cultural types of the R. solani isolates were confirmed by the sequence analysis. The pathogenicity tests revealed that the isolates of R. solani AG-1(IB) caused only leaf rot symptoms on the inoculated plants, and those of R. solani AG-2-2(IIIB) leaf rot and stem rot symptoms. The induced symptoms were similar to those observed in the fields investigated. Leaf and stem rot of three-leaf ladybell caused by the two anastomosis groups and cultural types of R. solani is first reported in this study.

• 한국식물병리학회지
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• 제1권2호
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• pp.122-127
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• 1985

도열병 저항성유전자 $Pi-\alpha$를 가지고 있는 Aichi-asahi, Toyotama, Yamabiko를 공시하여 접종전$\cdot$접종후 $23/15^{\circ}C\;,\;29/21^{\circ}C$에 각각 3일간 처리하였다. 도열병균 6개 균주를 접종한 후, 도열병균의 침입$\cdot$균사신전$\cdot$병반수를 조사한 결과, $29/21^{\circ}C$에 처리한 유균에서 침입율이 높고 형성 병반수도 많았다. 균사신전도와 피침입세포수는 $29/21^{\circ}C$ 경우 접종후 72시간에서 96시간 사이에 현저히 증가하였다. 그러나 $23/15^{\circ}C$에 처리한 유균에서 침입$\cdot$균사신전이 억제되어 병반형성이 지연되었다

• Mycobiology
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• 제29권1호
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• pp.19-26
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• 2001

Defense mechanisms against anthracnose disease caused by Colletotrichum orbiculare on the leaf surface of cucumber plants after pre-treatment with plant growth promoting rhizobacteria(PGPR), amino salicylic acid(ASA) or C. orbiculare were compared using a fluorescence microscope. Induced systemic resistance was mediated by the pre-inoculation in the root system with PGPR strain Bacillus amylolquefaciens EXTN-1 that showed direct antifungal activity to C. gloeosporioides and C. orbiculare. Also, systemic acquired resistance was triggered by the pre-treatments on the bottom leaves with amino salicylic acid or conidial suspension of C. orbiculare. The protection values on the leaves expressing SAR were higher compared to those expressing ISR. After pre-inoculation with PGPR strains no change of the plants was found in phenotype, while necrosis or hypersensitive reaction(HR) was observed on the leaves of plants pre-treated with ASA or the pathogen. After challenge inoculation, inhibition of fungal growth was observed on the leaves expressing both ISR and SAR. HR was frequently observed at the penetration sites of both resistance-expressing leaves. Appressorium formation was dramatically reduced on the leaves of plants pre-treated with ASA, whereas EXTN-1 did not suppress the appressorium formation. ASA also more strongly inhibited the conidial germination than EXTN-1. Conversely, EXTN-1 significantly increased the frequency of callose formation at the penetration sites, but ASA did not. The defense mechanisms induced by C. orbiculare were similar to those by ASA. Based on these results it is suggested that resistance mechanisms on the leaf surface was different between on the cucumber leaves expressing ISR and SAR, resulting in the different protection values.

• 한국식물병리학회지
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• 제3권1호
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• pp.3-7
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• 1987

도열병에 대해 감수성을 보이는 낙동과 성체식물저항성을 보이는 도봉의 건전엽과 도열병 감염엽내의 에탄올가용성 아미노산과 페놀화합물을 양적으로 분석하였다. 접종 3일후에는 가용성 아미노산과 페놀화합물의 수준은 건전엽과 비슷하였다. 도열병 병반이 접종 5일 후에 감염엽에 나타났을 때 가용성 아미노산과 페놀화합물은 5엽기와 3엽기에서 증가하기 시작하였고, 접종 7일 후에서는 이들 화합물의 수준은 5엽기와 8엽기에서 건전엽보다 약 $1.5\~3$배 더 많았다. 도열병 감염동안 비록 도봉이 도열병에 대해 낙동보다 덜 감염되었지만 5엽기와 8엽기의 건전엽과 감염엽에서 성체식물저항성 품종 도봉의 가용성 아미노산 및 페놀화합물 함량은 감수성 품종 낙농의 함량보다 높았다. 벼품종 도봉이 도열병에 감염동안 아미노산과 페놀화합물 함량이 현저하게 증가하여 성체식물저항성이 발현하는데 중요한 역할을 할지 모른다.

• Current Research on Agriculture and Life Sciences
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• 제31권4호
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• pp.245-249
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• 2013

In 2008, leaf blight symptoms were observed on several Chinese chive farms in Sangju. The Pathogenicity of the isolate was confirmed by artificial inoculation, where the pathogen exhibited a strong pathogenicity toward healthy plants. Morphological classification identified the isolate as from the Fusarium genus. For further analysis, PCR and phylogenetic classification were performed with ITS region and 28S rRNA gene which are commonly used for fungal identification. However, the results provided a poor resolution. To solve this problem, we analyzed translation elongation factor 1-alpha (TEF-$1{\alpha}$) gene. The analyzed results using TEF-$1{\alpha}$ gene indicated that the isolate was F. proliferatum. Therefore, it is assumed that TEF-$1{\alpha}$ gene is important when Fusarium sp. was identified using molecular classification method.