• The Plant Pathology Journal
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• v.21 no.3
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• pp.214-220
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• 2005

Vegetative compatibility groups (VCGs) of Fusarium oxysporum f. sp. radicis-lycopersici isolates collected from tomatoes in Korea were analyzed to determine the genetic characteristics and compared to those of foreign isolates. In comparison of VCG specificity with foreign VCG subgroup testers, Korean isolates were revealed to be VCG 0094 and to be similar to those of Israel and Florida, USA having a 'Universal' property. Results of this study will contribute the effective control of disease through precise estimation of fungal damage, the prediction of new pathogenic isolates appearance, and the movement of foreign pathogens.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.96-96
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• 2005

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.417-419
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• 2022

농축업에 ICT 기술을 접목한 스마트 팜은 생육환경을 자동으로 조절하여 노동력 등을 줄이고도 생산성과 품질을 향상시키는 것이 큰 장점이다. 하지만, 수익으로 이어지는 출하량과 품질 유지를 위해서 병충해에 주의를 기울여야 함은 여전하다. 따라서 토마토 잎 병충해 발생 시, 적절한 대응을 통해 더 큰 피해를 막을 수 있으므로, 초기 증상을 포착하는 기법을 개발한다. 오픈 데이터 셋인 Ai hub 의 시설작물 질병 데이터셋과 추가로 확보한 샘플을 포함해 2 개의 충해, 4 개의 병해에 1,231 장으로 데이터셋을 직접 구성해서 학습했다. 객체 탐지와 세그먼테이션이 동시에 가능하며 작은 병변도 잘 탐지하는 모델을 사용해서 총 6 가지 병충해에 대한 뚜렷한 증상 탐지를 보여주었다.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.323-332
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• 2024

Circulating hydroponic cultivation has the advantage of reducing soil and water pollution problems caused by discharge of fertilizer components because the nutrient solution is reused. However, cyclic hydroponic cultivation has a low biological buffering capacity and can cause outbreaks of infectious root pathogens. Therefore, it is necessary to develop technologies or disinfection systems to control them. This study used dielectric barrier discharge plasma, which generates various persistent oxidants, to treat Fusarium oxysporum f. sp., a pathogen that causes wilt disease. Batch and intermittent continuous inactivation experiments were conducted, and the results showed that the total residual oxidant was persistent in intermittent plasma treatment at intervals of 2-3 days, and F. oxysporum was treated efficiently. Intermittent plasma treatment did not inhibit the growth of tomatoes.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.557-567
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• 2012

This study was conducted to achieve basal information for the development of tomato cultivars with disease resistances through marker-assisted backcross (MAB). Ten inbred lines with TYLCV, late blight, bacterial wilt, or powdery mildew resistance and four adapted inbred lines with superior horticultural traits were collected, which can be useful as the donor parents and recurrent parents in MAB, respectively. Inbred lines collected were evaluated by molecular markers and bioassay for confirming their disease resistances. To develop DNA markers for selecting recurrent parent genome (background selection) in MAB, a total of 108 simple sequence repeat (SSR) primer sets (nine per chromosome at average) were selected from the tomato reference genetic maps posted on SOL Genomics Network. Genetic similarity and relationships among the inbred lines were assessed using a total of 303 polymorphic SSR markers. Similarity coefficient ranged from 0.33 to 0.80; the highest similarity coefficient (0.80) was found between bacterial wilt-resistant donor lines '10BA333' and '10BA424', and the lowest (0.33) between a late blight resistant-wild species L3708 (S. pimpinelliforium L.) and '10BA424'. UPGMA analysis grouped the inbred lines into three clusters based on the similarity coefficient 0.58. Most of the donor lines of the same resistance were closely related, indicating the possibility that these lines were developed using a common resistance source. Parent combinations (donor parent ${\times}$ recurrent parent) showing appropriate levels of genetic distance and SSR marker polymorphism for MAB were selected based on the dendrogram. These combinations included 'TYR1' ${\times}$ 'RPL1' for TYLCV, '10BA333' or '10BA424' ${\times}$ 'RPL2' for bacterial wilt, and 'KNU12' ${\times}$ 'AV107-4' or 'RPL2' for powdery mildew. For late blight, the wild species resistant line 'L3708' was distantly related to all recurrent parental lines, and a suitable parent combination for MAB was 'L3708' ${\times}$ 'AV107-4', which showed a similarity coefficient of 0.41 and 45 polymorphic SSR markers.

• Research in Plant Disease
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• v.9 no.2
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• pp.89-93
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• 2003

An isolate of Tobacco mosaic virus (TMV) was isolated from potato cultivar ‘Chubak’ showing vein clearing and mild mosaic at Namhae in Korea. This isolate, TMV-St, was differentiated from other tobamoviruses based on biological properties, serological relationships and nucleotide sequence analyses of coat protein genes. TMV-St caused typical symptoms on four indicator plants as compared to the tobamovirus of TMV-U1, Pepper mild mottle virus (PMMoV), and Tomato mosaic virus (ToMV), which caused economic losses in Solanaceous vegetables, tomato, pepper, and eggplant. Remarkably, the TMV-St induced distinctly different symptom of systemic chlorotic spots on Chenophodium murale. On C. murale, Gomphorena globosa, and Nic-otiana rustica, the four viruses were classed by the virulence of systemic or local infections. In serological test TMV-St antiserum showed a precipitation line with each other tabamovirus. The CP gene of TMV-St contain 477 nucleotides, and the nucleotides sequence was the most similar to that of TMV-U1.

• Research in Plant Disease
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• v.23 no.4
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• pp.348-354
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• 2017

To investigate occurrence of root-knot nematode (RKN) in plastic house of central area of Korea, 132 soil samples were collected in cucumber, water melon, tomato, red pepper and strawberry fields from 2013 to 2015. Among 132 soil samples, 65 soil samples (49%) were infested with RKN and mean density of RKN was 178 second-stage juveniles per $100cm^3$ soil (min. 1 ~ max. 3,947). The frequency of RKN by regional was the highest in Chuncheon with 80%, followed by Cheonan (68%), Nonsan (36%), Buyeo (33%) and Yesan (30%). The frequency of RKN by crops was the highest in tomato with 83%, followed by cucumber (61%), strawberry (41%), red pepper (30%), watermelon (26%). To identify the species of RKN, fifteen populations were selected for representative populations. As a phylogenetic analysis of 15 populations, southern root-knot nematode (Meloidogyne incognita), peanut root-knot nematode (M. arenaria) and northern root-knot nematode (M. hapla) were identified with 47%, 20% and 33% ratio, respectively. In crops, M. incognita, M. arenaria and M. hapla were detected in tomato, M. incognita and M. arenaria were detected in cucumber and watermelon, and M. hapla was detected in strawberry and lettuce. Thus, there should be a continuous management to major species of each crops to prevent dispersal of RKN damages.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.319-325
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• 1999

A culture-dependent survey of bacterial community in the soil-root system of red pepper and tomato was conducted by dilution plate count method. The bacterial community within soil was not different from that of rhizoplane. However, the populations of fluorescent, pseudomonads were higher in rhizoplanes than in soils and higher in healthy rhizoplanes than in Phytophthora disease-infested rhizoplanes. The bacterial community of the pepper cropped soil and rhizoplanes was very similar to that of the tomato-cropped soil and rhizoplanes. Among 285 identified bacterial colonies, most colonies were belong to two groups by fatty acid analyses: 52% of the 285 colonies were belong to low G + C gram positive bacteria group. Bacillus spp. and 33% were belong to high G + C gram positive bacteria group. In order to use beneficial microorganisms to agro-ecosystem, these data of field trials should be intensively accumulated.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.194-199
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• 2005

In oder to select an antifungal substance-producing antagonistic bacterium against Fusarium oxysporum casuing fusarium wilt on tomato, strain BK4 was isolated from local soil of Gyeoungbuk and was identified as Bacillus thuringiensis by 16s rDNA analysis, biochemical test, and Mcirolog TM 3.0 System. The antibiotic of B. thuringiensis BK 4 was highly produced at $30^{\circ}C$ in nutrient broth (pH 9.0). The crude antibiotic was even stable at $121^{\circ}C$ and more stable at slight alkalic condition than acid condition. It was also remained $50{\%}$ activity at pH 3.0. B. thuringiensis BK4 showed the inhibition of spore germination and the biocontrol ability against F. oxysporum causing fusarium wilt of tomato in vivo test. According to these results, B. thuringiensis BK4 was enough to use with a microbial agent for biocontrol against fusarium wilt.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.737-741
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• 1999

We surveyed the physiological disorders of fruit vegetables grown in the greenhouse in Kyungbuk province in 1998. Greenhouses used for cultivation were mostly single or multi-span iron pipe houses covered with polyethylene film. Single span greenhouses were used for strawberry, oriental melon and watermelon. Fifty six percent of the surveyed farms was a mono-cropping system for oriental melon and tomato. There were greenhouses used for successive cultivation for 10 years or more for strawberry and oriental melon in Koryeong and Seongju. Varieties of fruit vegetables cultivated were diverse, especially in cucumber and watermelon. In strawberry, malformed fruits were observed most frequently in March and the small fruits at late harvest period. Leaf chlorosis, stunt plants and runner outbreak were also found during the growing season. In tomato, occurrence of malformed fruits was severe from March to May, and occurrence of cracked fruits and blossom- end rot was also severe in October and November. The self topping and abnormal stem in tomato were problem in hydroponic cultures in August and November, respectively. Malformed cucumber fruits, such as curved, club shaped, irregular shaped and narrow necked, occurred at late season. Umbrella-shaped leaf in cucumber in summer were caused by calcium deficiency. Most serious disorders were fermented and malformed fruits occurring from March to May in oriental melon, and cracked fruits occurring from April to May in watermelon. At late growing stage of melons the leaf chlorosis occurred with complex symptoms of leaf disease. Growers had little knowledge on physiological disorders, and also on diagnose and measures to cure the disorders. Most growers pointed out that poor soil environment and temperature management in the greenhouse as the main causes of physiological disorders.