• The Plant Pathology Journal
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• v.38 no.3
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• pp.254-260
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• 2022

Fusarium incarnatum-equiseti species complex (FIESC) contain over 40 members. The primer pair Smibo1FM/Semi1RM on the RPB2 partial gene has been reported to be able to identify Fusarium semitectum. The F. fujikuroi species complex (FFSC) contains more than 50 members. The F. verticillioides as a member of this complex can be identified by using VER1/VER2 primer pair on the CaM partial gene. In this research, the Smibo1FM/Semi1RM can amplify F. sulawesiense, F. hainanense, F. bubalinum, and F. tanahbumbuense, members of FIESC at 424 bp. The VER1/VER2 can amplify F. verticillioides, F. andiyazi, and F. pseudocircinatum, members of FFSC at 578 bp. Polymerase chain reaction-restriction fragment length polymorphism by using the combination of three restriction enzymes EcoRV, MspI, and HpyAV can differentiate each species of FIESC used. The two restriction enzymes HpaII and NspI can distinguish each species of FFSC used. The proper identification process is required for pathogen control in the field in order to reduce crop yield loss.

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

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.297-312
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• 2020

Wilted soybean plants were collected from soybeans cultivation fields in Korea from 2014 to 2016. Fusarium spp., Colletotrichum spp., Rhizoctonia spp., Macrophomina sp., Phytophthora spp., and Calonectria ilicicola were obtained from the infected samples. Out of these, Fusarium spp. were the dominant species (79.1%). In total, 53 isolates were identified as F. solani species complex, F. oxysporum species complex, F. graminearum species complex, and F. fujikuroi species complex based on mycological characteristics. Sequence typing analysis was conducted using translation elongation factor 1 alpha (TEF) to confirm the identification of isolates. All isolates were identified as F. solani, F. oxysporum, F. commune, F. asiaticum, and F. fujikuroi based on phylogenetic analysis of TEF sequences. Pathogenicity of 44 isolates was tested on three cultivars of soybean using the root dip inoculation method. Out of 5 Fusarium species, only F. asiaticum could not cause the symptoms or be weak. Ten isolates were selected based on pathogenic characters and species identification to investigate the host range and screen soybean cultivars for resistance. Fusarium solani, F. oxysporum, and F. commune were aggressive only to soybean, and F. fujikuroi was aggressive to kidney bean, yellow cowpea, black cowpea, adzuki bean as well as soybean. All 13 Korean soybean cultivars were susceptible to F. commune and F. fujikuroi. Out of 13 cultivars, cv. Janggi, cv. Poongsannamul, and cv. Socheongja were resistant to Fusarium wilt, while cv. Hwanggeumol and Chamol were susceptible to Fusarium wilt.

• Research in Plant Disease
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• v.24 no.4
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• pp.313-320
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• 2018

Fusarium infection rate of the paddy rice grain after harvest seemed to be influenced by the average temperature from late July (before heading) to the end of September (during ripening). In case of 2010 and 2013 in which average temperature of the same period was similar, Fusarium infection was related to cumulative precipitation, cumulative precipitation days, and precipitation durations over two days. The distribution ratio of Fusarium species complex isolated from paddy rice grains after harvest was 57% in 2010 and 45% in 2013 for Fusarium graminearum species complex (FGSC), 35% and 50% for Fusarium incarnatum-equiseti species complex, and 8% and 5% for Fusarium fujikuroi species complex (FFSC). The distribution ratios of FGSC and FFSC were higher in 2010 than 2013. Among the total 26 promoted rice varieties, the 'Mihyang' showed resistant response against the natural infection with Fusarium species belonging to FGSC and the varieties of 'Nampyeong', 'Hi-ami'and 'Younghojinmi' showed resistant response against the natural infection with overall Fusarium pathogens. Majority of the promoted rice varieties could not be classified for resistance or susceptibility. These results are valuable as basic data to determine the resistance and susceptibility of rice variety against Fusarium spp. infection in the field.

• Mycobiology
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• v.30 no.3
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• pp.139-145
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• 2002

Gibberella fujikuroi is species complex. This species complex includes Fusarium tabacinum, F. moniliforme(=F. verticillioides), F. nygamai, F. proliferatum as well as F. subglutinans. Our objective was to develop a technique to differentiate between isolates of F. subglutinans, F. proliferatum and F. verticillioides. Thirty-two strains of F. subglutinans, six strains from F. verticillioides and five strains of F. Proliferatum isolated from maize in Austria were studied using random amplified polymorphic DNA(RAPD). F. subglutinans strains clustered very closely, with similarity ranging from $87{\sim}100%$. On the other hand, all the amplification patterns of F. verticillioides were identical, as well as in the case of F. proliferatum. Our results indicated that these Fusaria species are distinct species and hence RAPD markers can be quick and reliable for differentiating them.

• The Plant Pathology Journal
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• v.33 no.2
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• pp.118-124
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• 2017

Bell pepper is an economically important crop worldwide; however, production is restricted by a number of fungal diseases that cause significant yield loss. Chemical control is the most common approach adopted by growers to manage a number of these diseases. Monitoring for the development to resistance to fungicides in pathogenic fungal populations is central to devising integrated pest management strategies. Two fungal species, Fusarium incarnatum-equiseti species complex (FIESC) and Colletotrichum truncatum are important pathogens of bell pepper in Trinidad. This study was carried out to determine the sensitivity of 71 isolates belonging to these two fungal species to fungicides with different modes of action based on in vitro bioassays. There was no significant difference in log effective concentration required to achieve 50% colony growth inhibition ($LogEC_{50}$) values when field location and fungicide were considered for each species separately based on ANOVA analyses. However, the $LogEC_{50}$ value for the Aranguez-Antracol locationfungicide combination was almost twice the value for the Maloney/Macoya-Antracol location-fungicide combination regardless of fungal species. $LogEC_{50}$ values for Benomyl fungicide was also higher for C. truncatum isolates than for FIESC isolates and for any other fungicide. Cropping practices in these locations may explain the fungicide sensitivity data obtained.

• Research in Plant Disease
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• v.18 no.4
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• pp.310-316
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• 2012

Gibberellea fujikuroi species (Gf) complex comprises at least 15 species, most of which not only causes serious plant diseases, but also produces mycotoxins including fumonisins. Here, we focused on the abilities of the field isolates belonging to the Gf complex associated with rice and corn, respectively in Korea to produce fumonisin, all of which were confirmed to carry FUM1, the polyketide synthase gene essential for fumonisin biosynthesis. A total of 88 Gf complex isolates (55 F. fujikuroi, 10 F. verticillioides, 20 F. proliferatum, 2 F. subglutinans, and 1 F. concentricum), and 4 isolates of F. commune, which is a non-member of Gf complex, were grown on rice substrate and determined for their production levels of fumonisins by a HPLC method. Most isolates of F. verticillioides and F. proliferatum, regardless of host origins, produced fumonisin $B_1$ and $B_2$ at diverse ranges of levels ($0.5-2,686.4{\mu}g/g$, and $0.7-1,497.6{\mu}g/g$, respectively). In contrast, all the isolates of F. fujikuroi and other Fusarium species examined produced no fumonisins or only trace amounts ($<10{\mu}g/g$) of fumonisins. Interestingly, the frequencies of relatively high fumonisin-producers among the F. proliferatum and F. fujikuroi isolates derived from corn were higher than those among the fungal isolates from rice. In addition, it is a first report demonstrating the ability of the FUM1-carrying F. commune isolates from rice to produce fumonisins.

• Research in Plant Disease
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• v.17 no.3
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• pp.369-375
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• 2011

Fusarium verticillioides (teleomorph: Gibberella moniliformis), a member of the Gibberellea fujikuroi species complex, causes rots of corn stalks and ears, and produces a group of mycotoxins known as fumonisins that are harmful to animals and humans. Here, we focus on the development of a species-specific PCR primer set for differentiating F. verticillioides from other fumonisin-producing Fusarium species belonging to the species complex, such as F. proliferatum, F. fujikuroi, and F. subglutinans that are frequently associated with corn. The specific primers (RVERT1 and RVERT2) derived from the nucleotide sequences of RNA polymerase II beta subunit (RPB2) gene amplified a 208 bp-DNA fragment from only F. verticillioides isolates among the potential fumonisin-producing species examined; all of these isolates were shown to carry FUM1 required for fumonisin biosynthesis. The PCR detection limit using this specific primer set was approximately 0.125 pg/${\mu}l$ genomic DNA of F. verticillioides. In addition, the F. verticillioides-specfic fragment was successfully amplified from genomic DNAs of corn samples contaminated with Fusarium spp. This primer set would provide a useful tool for the detection and differentiation of potential fumonisin-producing F. verticillioides strains in cereal samples.

• The Plant Pathology Journal
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• v.28 no.3
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• pp.311-316
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• 2012

Fusarium root disease can be a serious problem in forest and conservation nurseries in the western United States. Fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. Fusarium spp. within the F. oxysporum species complex have been recognized as pathogens for more than a century, but attempts to distinguish virulence by correlating morphological characteristics with results of pathogenicity tests were unsuccessful. Recent molecular characterization and pathogenicity tests, however, revealed that selected isolates of F. oxysporum are benign on Douglas-fir (Pseudotsuga menziesii) seedlings. Other morphologically indistinguishable isolates, which can be virulent, were identified as F. commune, a recently described species. In a replicated greenhouse study, inoculating Douglas-fir seedlings with one isolate of F. oxysporum prevented expression of disease caused by a virulent isolate of F. commune. Moreover, seedling survival and growth was unaffected by the presence of the F. oxysporum isolate, and this isolate yielded better biological control than a commercial formulation of Bacillus subtilis. These results demonstrate that an isolate of nonpathogenic F. oxysporum can effectively reduce Fusarium root disease of Douglas-fir caused by F. commune under nursery settings, and this biological control approach has potential for further development.

• Research in Plant Disease
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• v.29 no.2
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• pp.118-129
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• 2023

Fusarium sambucinum species complex (FSAMSC) is an important taxonomic group, causing severe plant diseases. Many studies were carried out on FSAMSC plant diseases in Korea, but only 2 species (F. graminearum, F. sambucinum) from 14 host plants were registered in the List of Plant Disease in Korea. To clarify FSAMSC diversity and their pathogenecity, we examined FSAMSC isolates preserved in the Korean Agricultural Culture Collection. Fifty-seven strains were reidentifed as 7 species (F. asiaticum, F. graminearum, F. vorosii, F. meridionale, F. boothii, F. kyushuense, F. armeniacum) based on multi-locus sequence typing analysis. According to previous reports and result of this study, 5 species (F. asiaticum, F. graminearum, F. vorosii, F. armeniacum, F. sambucinum) were pathogenic on 24 host plants in FSAMSC, while the pathogenicity of 3 species (F. meridionale, F. boothii, F. kyushuense) were not clear.