• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.117.3-118
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• 2003

We tested for the presence of double-stranded RNA (dsRNA) mycovirus in 827 Fusarium graminearum isolated from diseased barley and maize. dsRNA mycoviruses with various sizes were isolated. Of them, it was previously reported that dsRNA from DK2l isolate had pronounced morphological changes, including reduction in mycelial growth, increased to red pigmentation, reduced virulence and sporulation. (Chu et al., Appl. Environ. Microbiol. 2002). For better understanding of this hypovirulence associated with DK2l dsRNA virus, we determined the complete nucleotide sequence of dsRNA genome and named Fusarium hypovirus DK2l strain (Fhv-DK2l ). Genomic RNA of Fhv-DK2l was determined to be 6625 nucleotides in length excluding the poly (A) tail and contained three putative open reading frame. RNA-dependent RNA polymerase (RdRp) and helicase domain were expected in ORF A, 54 to 4709 nucleotide position. ORE B, 4752 to 5216 nucleotide position, and ORF C, 5475 to 6578 nucleotide position, were predicted to encode 16.7kDa and 41.3kDa protein respectively each. We could not detect any conserved domains from these two proteins. Phylogenetic analysis showed Fhv-DK2l was related to Cryphonectria hypovirus 3. Ten additional isolates were found that were infected with dsRNA mycoviruses. These mycoviruses contain 2 to 4 different segments of dsRNAs with the size range of approximately 1.7 to 10-kbp in length. The presence of dsRNAs isolates did not affect colony morphology and were transmissible through conidia and ascospore with incidence of 30-100％. These results indicate that there is genomic diversity of dsRNA mycoviruses that infect F. graminearum isolates and that impact of virus infection on host's morphology and virulence is determined by the interaction between dsRNAs and the fungal host, not by the mere presence of the dsRNAs

• 한국균학회지
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• 제37권2호
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• pp.121-129
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• 2009

In 2007, a total of 77 isolates of Fusarium spp. were obtained from ear rot symptoms of corns collected from 5 locations in Gangwon Province, Korea. The fungal isolates were identified based on their morphological features. Out of the isolates, fifteen isolates were identified as Fusarium verticillioides which formed microconidia in long chains on monophialides. Four isolates were identified as F. subglutinans which formed microconida only on false heads. Six isolates were identified as F. graminearum which produced red pigment in PDA culture. Besides these Fusarium species, F. napiform, F. nygamai, and F. oxysporum were identified from the rest isolates. To assess for genetic diversity of the isolates, a random amplified polymorphic DNA(RAPD) technique was carried out using URP primers. The results from the RAPD analysis showed that the isolates from corn were divided into 6 groups. These RAPD groups of the Fusarium species corresponded to morphological characters of the Fusarium species. The phylogenetic analysis of most isolates by DNA sequencing of EF-1$\alpha$ gene corresponded to morphological characters of the Fusarium species. The results of pathogenicity tests by two inoculation methods revealed that F. verticillioides, F. graminearum and F. subglutinans are strongly pathogenic to corn stalks.

• The Plant Pathology Journal
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• 제37권5호
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• pp.455-464
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• 2021

Forty-eight spring barley genotypes were evaluated for deoxynivalenol (DON) concentration under natural infection across 5 years at Harrington, Prince Edward Island. These genotypes were also evaluated for Fusarium head blight (FHB) severity and DON concentration under field nurseries with artificial inoculation of Fusarium graminearum by the grain spawn method across 2 years at Ottawa, Ontario, and one year at Hangzhou, China. Additionally, these genotypes were also evaluated for FHB severity under greenhouse conditions with artificial inoculation of F. graminearum by conidial suspension spray method across 3 years at Ottawa, Ontario. The objective of the study was to investigate if reactions of barley genotypes to artificial FHB inoculation correlate with reactions to natural FHB infection. DON concentration under natural infection was positively correlated with DON concentration (r = 0.47, P < 0.01) and FHB incidence (r = 0.56, P < 0.01) in the artificially inoculated nursery with grain spawn method. Therefore, the grain spawn method can be used to effectively screen for low DON. FHB severity, generated from greenhouse spray, however, was not correlated with DON concentration (r = 0.12, P > 0.05) under natural infection and it was not correlated with DON concentration (r = -0.23, P > 0.05) and FHB incidence (r = 0.19, P > 0.05) in the artificially inoculated nursery with grain spawn method. FHB severity, DON concentration, and yield were affected by year, genotype, and the genotype × year interaction. The effectiveness of greenhouse spray inoculation for indirect selection for low DON concentration requires further studies. Nine of the 48 genotypes were found to contain low DON under natural infection. Island barley had low DON and also had high yield.

• The Plant Pathology Journal
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• 제40권2호
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• pp.106-114
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• 2024

Fusarium head blight (FHB), predominantly caused by Fusarium graminearum and F. asiaticum, is a significant fungal disease impacting small-grain cereals. The absence of highly resistant cultivars underscores the need for vigilant FHB surveillance to mitigate its detrimental effects. In 2023, a notable FHB outbreak occurred in the southern region of Korea. We assessed FHB disease severity by quantifying infected spikelets and grains. Isolating fungal pathogens from infected samples often encounters interference from various microorganisms. We developed a cost-effective, selective medium, named BGT (Burkholderia glumae Toxoflavin) medium, utilizing B. glumae, which is primarily known for causing bacterial panicle blight in rice. This medium exhibited selective growth properties, predominantly supporting Fusarium spp., while substantially inhibiting the growth of other fungi. Using the BGT medium, we isolated F. graminearum and F. asiaticum from infected wheat and barley samples across Korea. To further streamline the process, we used a direct PCR approach to amplify the translation elongation factor 1-α (TEF-1α) region without a separate genomic DNA extraction step. Phylogenetic analysis of the TEF-1α region revealed that the majority of the isolates were identified as F. asiaticum. Our results demonstrate that BGT medium is an effective tool for FHB diagnosis and Fusarium strain isolation.

• 한국균학회지
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• 제39권3호
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• pp.217-222
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• 2011

율무(Coix lacryma-jobi)는 동아시아에 자생하는 작물로, 종실은 주로 건강식품이나 의약용으로 사용되고 있다. 2006년부터 2008년까지 국내 율무 재배 지역에서 이삭마름 증상이 관찰되었다. 병징은 겉껍질이 변색되고, 내부의 속씨는 마르고 쭉정이가 되는 것이다. 159개의 Fusarium균을 분리하였고, 분리 빈도별로 F. graminearum(34%), F. proliferatum(14.5%), F. verticillioides(10.1%), F. equiseti(6.9%), F. fujikuroi(6.3%) 순으로 분리되었고, 그 밖에 F. subglutinans, F. semitectum, F. poae, F. sporodochioides가 분리되었다. 분리균주의 elongation factor 1 alpha 유전자의 염기서열 분석을 통한 계통분석을 수행한 결과, NCBI GenBank에 등록된 균주와 동일한 것을 확인하였다. 분리균주의 병원성 검정을 수행한 결과, F. graminearum, F. proliferatum, F. verticillioides가 병원성이 강하였다. 이 연구는 Fusarium균에 의해 발생한 율무 이삭마름 증상에 대한 첫 번째 보고이다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2018년도 춘계학술대회 및 임시총회
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• pp.33-33
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• 2018

Air-borne plant pathogenic fungus Fusarium graminearum and seed-borne plant pathogenic bacterium Burkholderia glumae are cause similar disease symptoms in rice heads. Here we showed that two pathogens frequently co-isolated in rice heads and F. graminearum is resistant to toxoflavin produced by B. glumae while other fungal genera are sensitive to the toxin. We have tried to clarify the resistant mechanism of F. graminearum against toxoflavin and the ecological reason of co-existence of the two pathogens in rice. We found that F. graminearum carries resistance to toxoflavin as accumulating lipid in fungal cells. Co-cultivation of two pathogens resulted in increased conidia and enhanced chemical attraction and attachment of the bacterial cells to the fungal conidia. Bacteria physically attached to fungal conidia, which protected bacterium cells from UV light and allowed disease dispersal. Chemotaxis analysis showed that bacterial cells moved toward the fungal exudation compared to a control. Even enhanced the production of phytotoxic trichothecene by the fungal under presence of toxoflavin and disease severity on rice heads was significantly increased by co-inoculation rather than single inoculation. This study suggested that the undisclosed potentiality of air-born infection of bacteria using the fungal spores for survival and dispersal.

• 한국균학회지
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• 제41권3호
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• pp.142-148
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• 2013

국내의 수수재배는 주로 소면적으로 이루어지며, 대부분 식용이나 사료용으로 사용되고 있다. 2007년부터 2009년까지 전국의 수수 재배 포장을 조사한 결과, 이삭에 곰팡이가 발생하는 증상을 다수 관찰하였다. 병징은 매우 다양한데, 심하게 감염된 이삭의 경우 곰팡이가 발생하였고, 부분적으로 감염된 경우에는 수수 종실이 변색되거나 불임립이 형성되었다. 총 90개의 Fusarium균을 분리하였으며, 형태적 배양적 특성 조사에 의한 동정 결과, F. thapsinum이 41개, F. proliferatum이 23개, F. graminearum이 12개 분리되었으며, F. incarnatum과 F. equiseti가 각각 5개, 3개 분리되었다. Elongation factor 1 alpha 유전자의 염기분석을 이용한 계통분석 결과, 대부분이 NCBI GenBank에 등록된 각 유전자와 일치하는 결과를 나타냈다. 분리된 병원균의 병원성 검정 결과, 우점종인 F. thapsinum, F. proliferatum, F. graminearum종이 병원성이 강한 것으로 조사되었다. 이 연구는 Fusarium균에 의해 발생한 수수 이삭곰팡이증상에 대한 첫 번째 보고이다.

• 식물병연구
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• 제26권4호
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• pp.250-255
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• 2020

페룰산 함량이 붉은곰팡이병과 곰팡이독소 저항성 곡류 육종의 선발지표가 될 수 있는지 알기 위해 밀, 보리, 벼 육성 품종 80점의 페룰산 함량을 조사하였다. 페룰산 함량은 보리 20품종이 1.66-2.77 mg/g, 밀 40품종이 0.56-1.53 mg/g이었으며 벼 20품종은 0.91-2.13 mg/g이었다. 이 중 페룰산 함량이 다른 밀과 보리 각 7품종을 선정하여 F. graminearum과 F. asiaticum 각 2균주의 붉은곰팡이병과 독소 생성량을 분석하였다. 밀 품종의 평균 병원성은 페룰산 함량이 높은 보리에 비해 유의하게 낮았고 밀 품종 간에는 상관관계가 없었다. 곰팡이독소도 병원성과 같이 페룰산 함량이 낮은 밀이 보리보다 생성량이 낮았다. 그러나 보리에서는 F. asiaticum 균주의 병원성과 독소 생성량이 페룰산 함량과 음의 상관관계를 나타내었다. 이 결과는 페룰산 함량이 밀과 보리에서 F. graminearum과 F. asiaticum에 의한 붉은곰팡이병과 독소 생성에 저항성 요인이 아님을 보여준다.

• The Plant Pathology Journal
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• 제17권6호
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• pp.389.4-389
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• 2001

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2002년도 총회 및 추계학술발표회
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• pp.124.1-124
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• 2002