• The Korean Journal of Mycology
• /
• v.33 no.2
• /
• pp.92-94
• /
• 2005

A orchid rotting fungus was isolated and identified. The isolate was consistent with the genus Fusarium in morphological and cultural characteristics. The partial 18S rRNA sequence of the isolate showed high similarity with anamorph or telemorph of Fusarium and other Fusarium species. In phylogenetic analysis, the isolates was poorly related to other Fusarium species. The isolate closely related to Fusarium sp. LP-A2/3.

• Korean Journal Plant Pathology
• /
• v.12 no.1
• /
• pp.47-57
• /
• 1996

병원성 Fusarium에 의한 아스파라거스 감염은 비병원성 Fusarium을 5일과 7일 전에 접종하였을 때 방제효과가 있었다. 비병원성 F. oxysporum은 F. moniliforme에 대하여 방제효과가 있었고, F. solani는 F. oxysproum에 대하여 방제효과가 있음이 밝혀졌다. 실험에 사용된 Fusarium 균들은 모두 주근과 측근의 말단 부위, 상처부위, 그리고 표피의 세포벽 사이를 통하여 감염하였다. 경우에 따라 감염하는 동안 appressorium과 유사한 구조를 형성하기도 하였고, 직접 감염하는 경우도 있었다. 병원성 그리고 비병원성 Fusarium 균 모두 공통적으로 생장점 부위를 통하여 감염하였다. 병원성이 강한 Fusarium 균의 경우 비병원성 균들보다 감염의 속도가 빨랐고 더욱 생장이 왕성하였다. F. solani는 생장속도나 기주 조직 침입속도가 매우 느렸다. 기주 감염의 결과 처음에는 cortical rot을 유발시켰고 나중에는 tracheary elements를 감염하고 결국은 조직의 괴사를 유발하는 것이 관찰되었다. 비병원성 F. oxysporum은 표피조직에 두터운 균사층을 형성하였고, 이는 병원성 Fusarium 균에 대한 방제효과를 나타내는 원인을 제공한 것으로 여겨진다. F. solani는 측근의 생성을 촉진시켜 표면적을 증대시킨 것으로 여겨진다. 결론적으로 AVFO와 F. solani를 이용하여 아스파라거스에 발생하는 병원성 Fusarium균의 침입을 저지할 수 있는 생물적 방제가 가능함이 밝혀졌다.

• The Plant Pathology Journal
• /
• v.25 no.3
• /
• pp.256-262
• /
• 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.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.260-267
• /
• 2004

Fusarium spp. were isolated from the postharvest fruit rot of oriental melon fruits at commercial fruit markets in Korea during 2001 to 2003. The decayed fruits were covered with the fungal mycelia and eventually soft rotted. The disease started at the fruit stalk area, the calyx end of the fruit and skin of fruit. As the disease advanced, white to pinkish mycelia covered with the surface of decayed fruit. The cultural and morphological characteristic of Fusarium spp. were compared with descriptions of those reported previously, and identified as Fusarium equiseti, F. graminearum, F. moniliforme, F. proliferatum, F. sambucinum, and F. semitectum. Pathogenicity of the isolates was proved by artificial wound and unwound inoculation onto the healthy fruits. Two days after inoculation, aerial mycelia were noticed on the wound inocultion region of the fruit and developed soft rot symptoms. Although Fusarium spp. causing fruit rot disease in oriental melon have been reported in Korea, identification of the those species was not described. Therefore, this is the first report of Fusarium spp. causing postharvest fruit rot on oriental melon in Korea.

• Mycobiology
• /
• v.44 no.3
• /
• pp.121-130
• /
• 2016

Recently, the Fusarium genus has been narrowed based upon phylogenetic analyses and a Fusarium-like clade was adopted. The few species of the Fusarium-like clade were moved to new, re-installed or existing genera or provisionally retained as "Fusarium." Only a limited number of reference strains and DNA marker sequences are available for this clade and not much is known about its actual species diversity. Here, we report six strains, preserved by the Belgian fungal culture collection BCCM/IHEM as a Fusarium species, that belong to the Fusarium-like clade. They showed a slow growth and produced pionnotes, typical morphological characteristics of many Fusarium-like species. Multilocus sequencing with comparative sequence analyses in GenBank and phylogenetic analyses, using reference sequences of type material, confirmed that they were indeed member of the Fusarium-like clade. One strain was identified as "Fusarium" ciliatum whereas another strain was identified as Fusicolla merismoides. The four remaining strains were shown to represent a unique phylogenetic lineage in the Fusarium-like clade and were also found morphologically distinct from other members of the Fusarium-like clade. Based upon phylogenetic considerations, a new genus, Pseudofusicolla gen. nov., and a new species, Pseudofusicolla belgica sp. nov., were installed for this lineage. A formal description is provided in this study. Additional sampling will be required to gather isolates other than the historical strains presented in the present study as well as to further reveal the actual species diversity in the Fusarium-like clade.

• 한국균학회소식:학술대회논문집
• /
• 2016.05a
• /
• pp.33-33
• /
• 2016

Mycotoxins are toxic secondary metabolites produced by fungi. They can be present in where agricultural-based commodities are contaminated with toxigenic fungi. These mycotoxins cause various toxicoses in human and livestock when consumed. Small grains including corn, barley, rice or wheat are frequently contaminated with mycotoxins due to infection mainly by toxigenic Fusarium species and/or under environment favorable to fungal growth. One of the most well-known Fusarium toxin groups in cereals is trichothecenes consisting of many toxic compounds. Deoxynivalenol (DON), nivalenol (NIV), T-2 toxin, and various derivatives belong to this group. Zearalenone and fumonisin (FB) are also frequently produced by many species of the same genus. In order to monitor Korean cereals for contamination with Fusarium and other mycotoxigenic fungal species as well, barley, corn, maize, rice grains, and soybean were collected from fields at harvest or during storage for several years. The fungal colonies outgrown from the grain samples were identified based on morphological and molecular characteristics. Trichothecene chemotypes of Fusarium species or presence of FB biosynthetic gene were determined using respective diagnostic PCR to predict possible toxin production. Heavy grain contamination with fungi was detected in barley, rice and wheat. Predominant fungal genus of barley and wheat was Alternaria (up to 90%) while that of rice was Fusarium (~40%). Epicoccum also appeared frequently in barley, rice and wheat. While frequency of Fusarium species in barley and wheat was less than 20%, the genus mainly consisted of Fusarium graminearum species complex (FGSC) which known to be head blight pathogen and mycotoxin producer. Fusarium composition of rice was more diverse as FGSC, Fusarium incarnatum-equiseti species complex (FIESC), and Fusarium fujikuroi species complex (FFSC) appeared all at considerable frequencies. Prevalent fungal species of corn was FFSC (~50%), followed by FGSC (<30%). Most of FFSC isolates of corn tested appeared to be FB producer. In corn, Fusarium graminearum and DON chemotype dominate within FGSC, which was different from other cereals. Soybeans were contaminated with fungi less than other crops and Cercospora, Cladosporium, Alternaria, Fusarium etc. were detected at low frequencies (up to 14%). Other toxigenic species such as Aspergillus and Penicillium were irregularly detected at very low frequencies. Multi-year survey of small grains revealed dominant fungal species of Korea (barley, rice and wheat) is Fusarium asiaticum having NIV chemotype.

• Korean Journal of Agricultural Science
• /
• v.49 no.1
• /
• pp.121-128
• /
• 2022

Fusarium wilt disease caused by Fusarium species is a major problem affecting cultivated cucurbit plants worldwide. Fusarium species are well-known soil-borne pathogenic fungi that cause Fusarium wilt disease in several cucurbit plants. In this study, we aimed to identify and classify pathogenic Fusarium species from cultivated Korean cucurbit plants, specifically watermelon and cucumber. Thirty-six Fusarium isolates from different regions of Korea were obtained from the National Institute of Horticulture and Herbal Science Germplasm collection. Each isolate was morphologically and molecularly identified using an internal transcribed spacer of ribosomal DNA, elongation factor-1α, and the beta-tubulin gene marker sequence. Fusarium species that infect the cucurbit plant family could be divided into three groups: Fusarium oxysporum (F. oxysporum), Fusarium solani (F. solani), and Fusarium equiseti (F. equieti). Among the 36 isolates examined, six were non-pathogenic (F. equiseti: 15-127, F. oxysporum: 14-129, 17-557, 17-559, 18-369, F. solani: 12-155), whereas 30 isolates were pathogenic. Five of the F. solani isolates (11-117, 14-130, 17-554, 17-555, 17-556) were found to be highly pathogenic to both watermelon and cucumber plants, posing a great threat to cucurbit production in Korea. The identification of several isolates of F. equiseti and F. oxysporum, which are both highly pathogenic to bottle gourd, may indicate waning resistance to Fusarium species infection.

• Journal of Ginseng Research
• /
• v.14 no.1
• /
• pp.50-56
• /
• 1990

Root-rot of ginseng caused by Fusarium solani is one of the most obstacles to ginseng cultivation. We evaluated some inoculating techniques of ginseng with Fusarium solani, for selection of disease resistant breeding lines. The most effective inoculating techniques evaluated were inserting toothpicks colonized by F. solani into the seedling roots in laboratory test and dusting seedlings with vermiculite after dipping in conidial sllspension and then replanting method in field test. The resistance to diseased by F. solani was lines of 82022 and 82066 in laboratory test. 82920-1 and 78093 in field test.

• Korean Journal of Microbiology
• /
• v.29 no.2
• /
• pp.123-129
• /
• 1991

In order to develop the protoplast fusion method of the strains of Fusarium, the interspecific protoplast fusion was attempted between Fusarium poae and F. sporotrichioides. Various auxotrophic mutants were isolated by the treatment of N-Methyl-N'-Nitro-N-Nitrosoguanidine. The optimal conditions for the formation and regeneration of protoplasts were examined and the characteristics of a fusant were studied. As a results, protoplasts were readily obtained from 18 hours cultured mycelia by the treatment of driselase for 3 hours and 0.6 M KCl as a best osmotic stabilizer at pH 6.0 for the formation of protoplast. Sucrose was the most suitable for the regeneration. Polyetylene glycol (M.W. 8,000) in $CaCl_{2}$-glycine solution was used to induce the protoplast fusion. The interspecific fusion frequency between protoplasts among the auxotrophic mutants of the two strains ranged from $2.7*10^{-2}$ to $5.7*10^{-3}$ . DNA content and cellulase activity were rather increased in the interspecific fusant. The lag phase of growth curve was slightly elongated in the fusant.

• Korean Journal of Organic Agriculture
• /
• v.12 no.2
• /
• pp.183-196
• /
• 2004

This study was carried out to screen and select the effects of antifungal bacterial strains which inhibit the growth of plant pathogen, Fusarium oxysporum(fusarium wilt) occurred in carnation plants in greenhouse. We isolated an effective bacterial strains and investigated into the antifungal activity of the antagonistic microorganism and it's identification. Twenty bacterial strains which strongly inhibited Fusarium oxysporum were isolated from roots of carnation plants and the soil in greenhouse, and the best antifungal bacteria designated as C121, was finally selected. Antagonistic bacterial strain, C121 was identified to be the genus Bacillus sp. based on the morphological, biochemical and cultural characterizations. The Bacillus sp. C121 showed 58.1% of antifungal activity against the growth of Fusarium oxysporum. By the bacterialization of the cultural broth and the heat bacterialization culture filtrate of it, Bacillus sp. C121 was shown 92.1% and 21.0% of antifungal activity, respectively.