• 식물병연구
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• 제28권4호
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• pp.231-236
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• 2022

2021년 5월 전북 김제시 화훼류 시설재배 농가에서 재배중인 옥시페탈룸(Oxypetalum coeruleum)에서 원형괴사 반점등의 전형적인 바이러스 감염 증상을 보이는 잎을 발견하였다. 이상 증상을 보이는 옥시페탈룸에서 원인 바이러스를 동정하기 위해 high-throughput sequencing을 수행한 결과 tomato spotted wilt virus (TSWV)에 의한 단독 감염이 확인되었다. TSWV의 감염을 확인하기 위해 TSWV 특이적인 프라이머를 이용하여 reverse transcription polymerase chain reaction (RT-PCR) 진단을 수행한 결과 777 bp의 예상 사이즈의 polymerase chain reaction 산물이 검출되었으며, TSWV의 기주인 청양고추(Capsicum annuum cv. 'Cheongyang')에 접종한 결과 TSWV의 전형적인 윤문무늬가 관찰되었으며 RT-PCR 진단법으로 고추에 감염된 TSWV를 확인할 수 있었다. 옥시페탈룸에서 분리한 TSWV (TSWV-Oxy)의 전체 염기서열을 결정하였으며, 기 보고된 13종 TSWV 분리주들의 S, M, L 유전체 염기서열과 상동성을 비교하였다. 'Oxy' 분리주는 국내 거베라에서 분리된 'Gumi' 분리주(MW048590, MW048591, MW048592)와 가장 상동성이 높았으며, 계통학적 연관성을 비교 분석한 결과 거베라 분리주 'Gumi' 및 고추 분리주인 'GS' (MF159043)와 'GC' (MF159066)와 가장 유연관계가 높은 것으로 확인되었다. 옥시페탈룸은 줄기삽목 혹은 종자로 증식되는 작물로서 시설재배지에서 연속적으로 재배되는 작물이다. TSWV는 총채벌레에 의해 잡초 등 TSWV 감염주로부터 시설 재배지로 유입되어 발생되었을 것으로 판단된다. 옥시페탈룸은 TSWV의 기주 중 하나로 보고되었으나 전 세계적으로 발생 및 증상에 관한 연구는 보고된 바 없다. 본 연구는 우리나라에서 옥시페탈룸에서 TSWV 발생에 관한 최초의 보고이다.

• 식물병연구
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• 제13권1호
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• pp.15-19
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• 2007

2003년부터 2005년 사이 국화 주요 재배단지인 구미, 마산, 부산에서 국화의 잎이 시들며 갈색으로 말라 죽는 증상이 발생하였다. 시들고 황화된 잎은 병징이 진행됨에 따라 잎 가장자리로부터 마르며 피해증상은 시든 잎으로부터 위쪽으로 진행되며 식물체 전체에 피해를 주고 있었다. 초기 병징이 종종 식물체의 한쪽 면에서만 먼저 나타나기 때문에 "반쪽시들음병"이라고 불리는 특징을 가진다. 또한 유관속 폐쇄에 의한 일반적인 시들음병과는 달리 물관부 갈변을 확인할 수 없었으며 시든 잎의 잎자루가 달린 기부를 잘라 해부현미경으로 관찰한 결과 옅은 갈색으로 내부세포가 갈변되어 있는 것을 관찰할 수 있었다. 병든 잎의 잎자루 기부 조직으로부터 병원균을 분리하여 동정한 결과 균학적 특징과 병원성을 검정한 결과 Verticillium dahliae으로 동정되었다. 배양적 특징으로는 균총은 처음에는 흰색 내지 옅은 크림색을 나타내고 배양기간이 경과됨에 따라 검은색 소형균핵(microsclerotia) 을 많이 형성하였다. 분생포자의 모양은 원통형 내지 타원형이며 무색으로 크기가 $2.5{\sim}8.8{\times}2.0{\sim}3.8{\mu}m$이었으며, 균사생장은 $25^{\circ}C$에서 가장 좋았다. 이상과 같이 Verticillium dahliae에 의해 국화에 발생한 반쪽시들음병의 병징과 균학적 특징에 대한 연구결과를 보고한다.

• Animal cells and systems
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• 제9권1호
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• pp.37-40
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• 2005

In okra Macrophomina phaseolina and Furasium verticilloides cause collar-rot, seedling-rot and other severe diseases at fruit maturing stages. These stages were located in all the components of the seeds. The seeds collected from seeds infected with Macrophomina phaseolina and Fusarium verticilloides revealed 100% infection. Such seeds resulted in pre- and post-emergence mortalities. Inoculated seeds also showed pre- and post-emergence death of the seedlings. The fungi seed-transmitted showed disease symptoms at different growth of okra plant. Fusarium verticilloides causes the wilt and Macrophomina phaseolina causes the collar-rot. Until now seed transmission of these fungi have not been studied. Hence, in the present study an attempt has been made to fill this lacunae.

• 한국응용곤충학회지
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• 제21권3호
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• pp.123-127
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• 1982

[ $1980\~1981$ ]년 사이에 전국의 14개 주요 담배 재배지역으로부터 채집, 분리한 담배 세균성마름병균(Pseudomonas solanacearum)의 가지, 토마토, 고추, 감자 및 담배에 대한 병원성반응을 조사한 결과, race 1 및 race 2에 속하였으며 또한 이 균주들의 생리적 특성 15종을 조사한 결과 biochemical type 1과 4로 판명되었다.

• 한국균학회지
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• 제51권2호
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• pp.141-146
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• 2023

Stem rot symptoms were observed in Gondre (Cirsium setidens) plants growing in a vinyl greenhouse in Taebaek, Korea during a disease survey in June 2022. The plants presented with dark brown to black rot on the stems at or above the soil line. Severely diseased plants displayed wilt and blight. Disease incidence among these plants ranged from 1 to 5%. Three isolates of Rhizoctonia sp. were obtained from the stem lesions of diseased plants. All isolates were identified as Rhizoctonia solani AG-2-2(IV) based on the morphological and cultural characteristics, results of the anastomosis test, and phylogenetic analysis. The pathogenicity of the isolates to Gondre plants was confirmed using an artificial inoculation test. The lesions induced by the inoculation test were similar to those observed in the investigated vinyl greenhouse. Here, we report a case of R. solani AG-2-2(IV) causing stem rot in Gondre.

• 식물병연구
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• 제19권4호
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• pp.265-272
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• 2013

전국 7개도 14개 시 군의 주요 고추 재배지에서 시들음 증상을 나타내는 식물체의 땅가 줄기에서 분리 선별된 63개 풋마름병균들의 특성을 조사하였다. 고추에서 분리된 풋마름병균들은 고추(cv. 대왕)와 토마토(cv. 서광)에 강한 병원성을 나타냈다. 모든 병원균들은 배양적, 생리 생화학적 특성 및 특이 PCR 검출에 의하여 Ralstonia solanacearum으로 동정되었다. 고추에서 분리된 63개 풋마름병균들은 race 1 계통으로 2가지 biovar로 구분되었는데, biovar 3은 17개 균주로 27%였고 biovar 4는 46개의 균주로 73%였으며, biovar 4의 생리형이 우점계통이었다. Rep-PCR에 의한 국내 고추 풋마름병균들의 유전적 다양성을 확인한 결과, 70%의 유사성을 기준으로 12개의 group으로 구분되었다. 이러한 결과들은 국내 고추 풋마름병에 대한 방제와 저항성 품종 육성에 중요한 기초 자료를 제공할 것이다.

• 한국균학회지
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• 제51권4호
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• pp.383-387
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• 2023

Peanut plants showing mild wilt were found in fields of Iksan, Korea, in August 2021. The diseased peanut plants were collected, and the causal pathogens were isolated using potato dextrose agar (PDA) medium. The isolated IS-1 strain formed white mycelia on PDA, which turned black with age. Sclerotia were produced on the PDA and barley leaves laid on water agar 7 d after incubation at 30℃. The sequences of both the internal transcribed spacer (ITS) region and calmodulin gene of IS-1 showed a 100% similarity with that of Macrophomina phaseolina. A phylogenetic tree constructed using the ITS regions of fungal pathogens causing disease in peanut plants indicated that the IS-1 stain belongs to M. phaseolina. The inoculation of IS-1 sclerotia into peanut seedlings resulted in yellowing and wilt symptoms in aboveground plants and brown to dark rots in roots 35-40 d after inoculation. Overall, the morphological characteristics, molecular identification, and pathogenicity of IS-1 indicate that the causal pathogen is M. phaseolina. This is the first report of charcoal rot caused by M. phaseolina on peanut plants in Korea. Further study is needed to develop the control measures for charcoal rot in peanut plants.

• The Plant Pathology Journal
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• 제40권3호
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• pp.310-321
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• 2024

Tomato yellow leaf curl virus (TYLCV) and tomato spotted wilt virus (TSWV) are well-known examples of the begomovirus and orthotospovirus genera, respectively. These viruses cause significant economic damage to tomato crops worldwide. Weeds play an important role in the ongoing presence and spread of several plant viruses, such as TYLCV and TSWV, and are recognized as reservoirs for these infections. This work applies a comprehensive approach, encompassing field surveys and molecular techniques, to acquire an in-depth understanding of the interactions between viruses and their weed hosts. A total of 60 tomato samples exhibiting typical symptoms of TYLCV and TSWV were collected from a tomato greenhouse farm in Nonsan, South Korea. In addition, 130 samples of 16 different weed species in the immediate surroundings of the greenhouse were collected for viral detection. PCR and reverse transcription-PCR methodologies and specific primers for TYLCV and TSWV were used, which showed that 15 tomato samples were coinfected by both viruses. Interestingly, both viruses were also detected in perennial weeds, such as Rumex crispus, which highlights their function as viral reservoirs. Our study provides significant insights into the co-occurrence of TYLCV and TSWV in weed reservoirs, and their subsequent transmission under tomato greenhouse conditions. This project builds long-term strategies for integrated pest management to prevent and manage simultaneous virus outbreaks, known as twindemics, in agricultural systems.

• The Plant Pathology Journal
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• 제40권5호
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• pp.463-474
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• 2024

Bananas (Musa spp.), which serve millions of people worldwide, face a serious threat from Fusarium wilt (FW) disease caused by Fusarium oxysporum f. sp. cubense (Foc). Developing disease-resistant varieties particularly through breeding is challenging due to banana's seedless nature (parthenocarpic). As an alternative, cold plasma (CP) technology, has the potential to be used for crop improvement. Our study demonstrates a favourable impact of CP on the growth performance of banana (Berangan cultivar, AAA) in terms of height, leaf number and stem diameter. CP-treated plants also displayed delayed disease progression as well as lower disease severity indicated by slightly lower value of leaf symptoms index and rhizome discoloration index compared to the control plants. Additionally, quantitative real-time polymerase chain reaction analysis revealed differential expression of several defence (PR1, WRKY22, PAL, and CEBiP) and growth (Cytochrome P450, NAC68, and CAT) related genes in CP-treated plants, particularly in conjunction with Foc infection. These findings shed light on the potential use of CP in managing FW in banana and offer insights into possible mechanism behind improved traits.

• The Plant Pathology Journal
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• 제25권1호
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• pp.95-98
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• 2009

The incidence and occurrence of virus infecting paprika (Capsicum annuum var. grossum) in Jeonnam province, the main areas of cultivation in Korea is undetermined. In this study, a total of 1,020 samples with virus-like symptoms were collected in Jeonnam province during summer season for 3 consecutive years (2002-2005) and were tested using enzyme linked immunosorbent assay (ELISA). Results showed that Pepper mottle virus (PepMoV), Broad bean wilt virus (BBWV), and Cucumber mosaic virus (CMV) were found to be the most prevalent viruses with a 3-year average percent incidence of 41.3, 19.8, and 4.4 respectively. Mixed infection with more than two viruses was also found with 3.5%, 17.0%, and 8.3%, respectively. Symptoms of these virus diseases were not evident at the seedling stage but slowly appeared at the transplanting stage and increased to the middle stage (4-5 months after transplanting) during the 3-year cultivation periods. Symptom appearance of infected plants however varied largely with transplanting time. Those plants transplanted from November to January were found to be infected with viruses in June, whereas symptoms appeared with in a month those plants transplanted from June to August. There were differences in the virus incidence from primary factor such as district, type of green house and variety, but these were not statistically significant (data not shown). Recommended control measures of paprika against these viruses is also discussed in this paper.