• 제목/요약/키워드: the rice blast fungus

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벼 신품종 및 계통의 지역별, 연도별 도열병 발병 차이 (III) (Temporal and Spatial Blast Incidence in New Cultivars and Elite Lines of Rice In Korea (III))

  • 라동수;오정행;한성숙;김장규
    • 한국식물병리학회지
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    • 제11권4호
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    • pp.338-343
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    • 1995
  • Incidence of blast caused by Pyricularia grisea on five new cultivars and four elite lines (C/L) of rice was investigated at different locations, Icheon, Chuncheon, Jecheon and Naju, 1992 to 1994. Disease indices of leaf blast on the tested C/L except Juanbyeo and Keumnambyeo ranged from 0 to 6 in the blast nursery. Under the field conditions, percentages of diseased leaf area of Kuemnambyeo were 6.5% in Jecheon and 2.8% in Icheon in 1993. The incidence of panicle blast on the C/L except Suweon 394 and Milyang 117 differed depending on the locations and years. In case of Unjangbyeo, panicle blast was rarely observed n the fields in Icheon and Naju, but the disease incidences were 21.8% in Jecheon in 1993 and 16.4% in Chuncheon in 1994. Race distribution of the blast fungus was variable according to the locations. The major race in the Jecheon site was KI-197, which was recently identified.

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Sectors from Phyricularia grisea Isolates on Edifenphos and Iprobenfos-Amended Media

  • Kim, Yun-Sung;Baik, Jong-Min;Kim, Eui-Nam;Kim, Ki-Deok
    • The Plant Pathology Journal
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    • 제20권4호
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    • pp.244-246
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    • 2004
  • Sectors of rice blast fungus, Pyricularia grisea, frequently appeared on potato dextrose agar amended with edifenphos and iprobenfos. Thus, we assessed the sector-forming frequency of isolates of P. grisea and compared the fungicide sensitivity between wild types and sectors against the fungicides. The 905 isolates of the fungus were obtained from rice-growing locations in Korea from 1997-1998. When the isolates were grown on potato dextrose agar amended with minimal inhibitory concentrations of edifenphos (20 ${\mu}$g a.i./ml)and iprobenfos (55 ${\mu}$g a.i./ml), they produced sectors that overcame the effect of the fungicides. Among the 905 isolates tested, 9.0% produced sectors against edifenphos and 5.6%, against iprobenfos. Different sector-forming frequencies were also observed among the 11 locations of Korea. Sectors obtained from the fungicide-amended media generally grew more than their counterpart wild types grown on the media with either edifenphos or iprobenfos, regardless of their origins. In this study, greater relative growth of sectors over wild types of tested isolates can support the resistant characteristic of the fungus to survive against the fungicides. Therefore, the results indicate that the sectoring in rice blast fungus, P. grisea, may play a role in the occurrence of fungicide resistance.

접종전 온도처리가 벼도열병균의 조직병리학에 미치는 영향 II. 도열병 병반발현에 미치는 접종전 처리온도의 영향 (Effect of Predisposing Temperatures on The Histopathology of the The Rice Blast Fungus, Pyricularia oryzae II. Effect of Four Predisposing Temperature Regimes on The Symptom Development)

  • 김장규;?크리
    • 한국응용곤충학회지
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    • 제19권1호
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    • pp.21-29
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    • 1980
  • 본 실험중 이병성품종인 Khao-tah-haeng 17에서는 4개 접종전처리온도어디서나 접종에 사용된 6개 균주에 대하여 저항성보다는 이병성병반이 많이 나타났다. Tetep, Carreon, IR36 및 Sensho에서는 이병성병반 보다는 저항성병반이 많이 나타났다. 저항성 및 이병성병반수 공히 접종전 처리온도간, 공시종간에 고도의 유의성이 있었다. 특정품종에서 이병성병반의 발현은 접종전처리온도와 두열병균균주에 의해서 좌우되었으며 저항성병반의 발현은 접종전처리온도보다는 도열병균균주에 의해서 좌우되었다.

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Genome-Wide Analysis of Hypoxia-Responsive Genes in the Rice Blast Fungus

  • Choi, Jaehyuk;Chung, Hyunjung;Lee, Gir-Won;Koh, Sun-Ki;Chae, Suhn-Kee;Lee, Yong-Hwan
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2015년도 춘계학술대회 및 임시총회
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    • pp.13-13
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    • 2015
  • Rice blast fungus, Magnaporthe oryzae, is the most destructive pathogen of rice in the world. This fungus has a biotrophic phase early in infection and switches to a necrotrophic lifestyle after host cell death. During the biotrophic phase, the fungus competes with host for nutrients and oxygen. Continuous uptake of oxygen is essential for successful establishment of blast disease of this pathogen. Here, we report transcriptional responses of the fungus to oxygen limitation. Transcriptome analysis using RNA-Seq identified 1,047 up-regulated genes in response to hypoxia. Those genes were involved in mycelial development, sterol biosynthesis, and metal ion transport based on hierarchical GO terms and well-conserved among three different fungal species. In addition, null mutants of three hypoxia-responsive genes were generated and tested for their roles on fungal development and pathogenicity. The mutants for a sterol regulatory element-binding protein gene, MoSRE1, and C4 methyl sterol oxidase gene, ERG25, exhibited increased sensitivity to hypoxia-mimetic agent, increased conidiation, and delayed invasive growth within host cells, suggesting important roles in fungal development. However, such defects did not cause any significant decrease in disease severity. The other null mutant for alcohol dehydrogenase gene, MoADH1, showed no defect in the hypoxia-mimic condition and fungal development. Taken together, this comprehensive transcriptional profiling in response to a hypoxia condition with experimental validations would provide new insights on fungal development and pathogenicity in plant pathogenic fungi.

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A Procedure for Inducing the Occurrence of Rice Seedling Blast in Paddy Field

  • Qin, Peng;Hu, Xiaochun;Jiang, Nan;Bai, Zhenan;Liu, Tiangang;Fu, Chenjian;Song, Yongbang;Wang, Kai;Yang, Yuanzhu
    • The Plant Pathology Journal
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    • 제37권2호
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    • pp.200-203
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    • 2021
  • Rice blast caused by the filamentous fungus Magnaporthe oryzae, is arguably the most devastating rice disease worldwide. Development of a high-throughput and reliable field blast resistance evaluation system is essential for resistant germplasm screening, resistance genes identification and resistant varieties breeding. However, the occurrence of rice blast in paddy field is easily affected by various factors, particularly lack of sufficient inoculum, which always leads to the non-uniform occurrence and reduced disease severity. Here, we described a procedure for adequately inducing the occurrence of rice seedling blast in paddy field, which involves pretreatment of diseased straw, initiation of seedling blast for the first batch of spreader population, inducing the occurrence of the second batch of spreader population and test materials. This procedure enables uniform and consistent infection, which facilitates efficient and accurate assessment of seedling blast resistance for diverse rice materials.

수도(水稻) 도열병(稻熱病)의 역학적(疫學的) 연구(硏究) III. 시기별(時期別) 포자비산(胞子飛散)과 출수기(出穗期) 잎도열병(病) 발생량(發生量)이 이삭도열병(病) 발생(發生)에 미치는 영향(影響) (Epidemiological Studies of Blast Disease of Rice Plant III. Effects of Conidial Number of Pyricularia oryzae collected in Different Periods and Occurrence Rate of Leaf Blast on the Occurrence of Panicle Blast of Rice)

  • 박종성;김홍기
    • 농업과학연구
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    • 제11권1호
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    • pp.61-67
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    • 1984
  • 출수기(出穗期)를 전후(前後)한 시기별(時期別) 벼 도열병균(病菌) 분생포자(分生胞子)의 비산량(飛散量) 및 잎 도열병(病) 발생량(發生量)과 이삭도열병(病) 발생(發生)과의 관계(關係)를 구명(究明)하여 방제(防除)의 기초자료(基礎資料) 및 병(病) 발생자찰자료(發生子察資料)를 얻고자 실시(實施)한 실험결과(實驗結果)는 다음과 같다. 출수(出穗) 5일전후(日前後)의 포자비산(胞子飛散)이 이삭도열병(病) 발생(發生)과 가장 밀접(密接)한 상관(相關)이 있었으며 출수기(出穗期) 잎도열병(病) 발생량(發生量)은 이병주율(罹病株率), 이병경율(罹病莖率) 모두 이삭도열병(病) 발생(發生)에 큰 영향(影響)이 없었다. 이삭도열병(病)의 방제적기(防除適期)는 도열병균(病菌)의 잠복기간(潛伏期間)을 고려(考慮)할 때 속효성(速效性) 약제(藥劑)는 출수(出穗)5~10일전(日前), 지효성약제(遲效性藥劑)는 10~15일전(日前)으로 추정(推定)된다.

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