• The Plant Pathology Journal
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• 제31권1호
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• pp.61-66
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• 2015

From study of antifungal actions on the rice sheath blight by using the extract of Ginkgo biloba outer seedcoats, we found that the extracts of Ginkgo biloba outer seedcoats of all treatment concentrations had inhibited the rice sheath blight. Among them, the most effective concentration was 250 mg/l at which the growth of microbe was 26 mm and even at the packaging test, when sprayed the G. biloba outer seedcoats at the level of 250 mg/l, the damage rate of the rice sheath blight was identified as 13%. As a result investigating the antifungal activity by separating polysaccharides from G. biloba outer seedcoats, it showed that the clear zone of 14 mm or more was formed at the concentration of 250 mg/l or higher. Based on these results, we concluded that the G. biloba outer seedcoat is a natural substance with the antifungal activity on the rice sheath blight.

• 농약과학회지
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• 제15권1호
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• pp.1-7
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• 2011

벼의 줄기에 주로 발생하는 잎집무늬마름병에 대한 thifluzamide의 방제 효과를 증진하기 위하여 벼 경엽을 통한 thifluzamide의 침투성을 강화하거나 벼 부착량을 증진할 수 있는 계면활성제를 선발하고 이를 함유하는 제제의 병 방제 효과를 측정하였다. 수화제 현탁액에 dodecaethylene glycol monohexadecyl ether를 첨가함으로써 벼 잎에 대한 thifluzamide의 침투성을 증진할 수 있었으나 병 예방효과는 오히려 감소하였다. 비이온성 계면활성제와 음이온성 계면활성제를 혼합하여 수화제 현탁액에 첨가하였을 때 유효성분 부착량이 약 5배 증대되었으나 잎집무늬마름병 예방효과는 약간 증가하여 $EC_{50}$가 5.8 mg $L^{-1}$에서 각각 4.4 mg $L^{-1}$와 3.4 mg $L^{-1}$로 감소하였다.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.374-383
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• 2021

Rhizoctonia solani is one of the major pathogens that cause sheath blight disease in rice. Sheath blight is one of the most difficult diseases to control. Biological control (with the use of rhizobacteria) is one of the ways to control this disease. Plant Growth Promoting Rhizobacteria (PGPR) is a rhizosphere bacterium that can be used to enhance plant growth. The composition of the rhizobacteria in organic and nonorganic soil is affected by the chemical characteristics of the soil - which influences plant physiology and root exudation patterns. This study aimed to obtain a species of rhizobacteria which shows PGPR activity, from organic and nonorganic rice fields and test their capability to suppress R. solani growth. Out of 23 isolates screened for PGPR activity, the following isolates showed high PGPR activity and were selected for in vitro antagonistic activity testing against R. solani: ISO6, ISO11, ISO15, ISN2, ISN3, and ISN7, The six isolates produced 43,42-75,23 ppm of IAA, possessed phosphorus solubilization capability, and chitinase-producing activity. ISO6 (54.88%) and ISN7 (83.33%) displayed high inhibition capacities against R. solani, in vitro. ISO6 and ISN7 inhibited the growth of R. solani lesions on rice leaves by 89% and 100% (without lesion), respectively, after 7 days of incubation. Analysis of their 16S rRNA sequences revealed that the ISO6 isolate was Citrobacter freundii and ISN7 isolate was Pseudomonas aeruginosa.

• 농약과학회지
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• 제19권4호
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• pp.394-398
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• 2015

본 연구는 잎집무늬마름병에 대한 약제방제수준을 설정하기 위하여 오대벼를 공시하여 시험을 수행하였다. 잎집무늬마름병 발병정도에 따라 수량에 미치는 관계를 분석하였으며, 수량 구성 요소인 주당 이삭수, 이삭당 립수, 등숙률, 천립중과의 관계를 분석하였다. 그 결과 발병주율에 대한 수량과의 관계는 r = -0.93, 이삭당 립수 r = -0.66, 등숙율은 r = -0.77로 고도의 유의성 있는 부의 상관이 있었으나, 주당 이삭수와 천립중은 유의한 상관이 인정되지 않았다. 따라서 본시험에서는 발병과 상관이 높은 수량에 대하여 경제적 방제수준은 발병주율 7.8%로 설정할 수 있었다.

• 한국유기농업학회지
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• 제19권spc호
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• pp.123-126
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• 2011

To investigate the forecasting of plant disease and insect for an agricultural complex and farm in environment-friendly cultivation of Rice, environment-friendly agricultural five complexs and five farms were selected in Youngam and Naju area, Jonnam, Korea. Preventation objects of plant disease and insect were leaf blast, neck blast, sheath blight, bacterial leaf blight, and hopper. Factors of sheath blight occurrence in environment-friendly agricultural complex were a fast transplanting time and a narrow planting density. Bacterial leaf blight in rice occurred severely in the area under water. Rice growth in environment-friendly agricultural complex was decreased heavy drying by hopper appearance.

• 한국응용곤충학회지
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• 제22권1호
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• pp.21-25
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• 1983

벼 잎집무늬마름병의 발생예찰방법을 개발하기 위하여 1976년부터 1981년까지 진흥과 유신을 공시하여 시험하였다. 그 결과 성숙기의 잎집무늬마름병 피해도는 7월중의 병반높이와 병반고율, 9월 11일의 병반지수에 의하여 추정할 수 있었다. 유신품종에 있어서 7월 11일의 최상위병반 높이와 성숙기의 피해도와는 관계는 $Y=4.64\chi-13.2,\;r=.840^{**}$이었다. 한편 약제방제시기와 회수시험결과는 잎집무늬마름병의 발병주율과 발병경율이 7월 11일에서 8월 1일 사이에 급격히 높아지는 사실과 7월중의 병반높이와 성숙기의 피해도와는 상관이 높은 것을 감안할 때 7월 15일과 7월 25일 또는 7월 25일과 8월 5일의 10일간격 2회방제가 가장 효과적이었다.

• The Plant Pathology Journal
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• 제38권6호
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• pp.572-582
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• 2022

Sheath blight disease caused by the necrotrophic, soilborne pathogen Rhizoctonia solani Kuhn, is the global threat to rice production. Lack of reliable stable resistance sources in rice germplasm pool for sheath blight has made resistance breeding a very difficult task. In the current study, 101 rice landraces were screened against R. solani under artificial epiphytotics and identified six moderately resistant landraces, Jigguvaratiga, Honasu, Jeer Sali, Jeeraga-2, BiliKagga, and Medini Sannabatta with relative lesion height (RLH) range of 21-30%. Landrace Jigguvaratiga with consistent and better level of resistance (21% RLH) than resistant check Tetep (RLH 28%) was used to develop mapping population. DNA markers associated with ShB resistance were identified in F₂ mapping population developed from Jigguvaratiga × BPT5204 (susceptible variety) using bulk segregant analysis. Among 56 parental polymorphic markers, RM5556, RM6208, and RM7 were polymorphic between the bulks. Single marker analysis indicated the significant association of ShB with RM5556 and RM6208 with phenotypic variance (R²) of 28.29 and 20.06%, respectively. Co-segregation analysis confirmed the strong association of RM5556 and RM6208 located on chromosome 8 for ShB trait. This is the first report on association of RM6208 marker for ShB resistance. In silico analysis revealed that RM6208 loci resides the stearoyl ACP desaturases protein, which is involved in defense mechanism against plant pathogens. RM5556 loci resides a protein, with unknown function. The putative candidate genes or quantitative trait locus harbouring at the marker interval of RM5556 and RM6208 can be further used to develop ShB resistant varieties using molecular breeding approaches.

• 농업과학연구
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• 제3권1호
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• pp.23-30
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• 1976

수도품종(水稻品種)의 파종기(播種期) 이동(移動)이 문고병(紋枯病) 발생(發生)에 미치는 영향(影響)을 조사(調査)하였던 바 다음과 같은 결과(結果)를 얻었다. 1). 이병경률(罹病莖率) 및 피해도(被害度)는 이앙기(移秧期)가 늦을수록 피해(被害)가 적었다. 2). 조생종(早生種)의 피해도(被害度)가 가장 크고 다음이 중생종(中生種)이며 만생종(晩生種)이 가장 적었다. 3). 7월(月) 28일(日) 조사(調査)한 이병경률(罹病莖率)은 통일계(統一系) 품종(品種)들이 Japonica계(系) 품종(品種)들보다 낮았으나 피해도(被害度)에는 유의성(有意性)이 없었다. 4). 피해도(被害度)는 출수기(出穗期)와 높은 상관(相關)을 보이고 있으며 이는 출수전(出穗前) 10일(日)부터 출수후(出水後) 30일(日)까지의 적산온도(積算溫度)와도 높은 상관(相關)을 보이고 있어, 수도생육후기(水稻生育後期)의 고온(高溫)이 문고병(紋枯病) 피해도(被害度)에 크게 작용(作用)하고 있음을 알 수 있다.

• The Plant Pathology Journal
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• 제37권1호
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• pp.57-71
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• 2021

Rice sheath blight (ShB), caused by Rhizoctonia solani Kühn AG1-IA, is one of the destructive rice diseases worldwide. The aims of this study were to develop biocontrol strategies focusing on field sanitation and foliar application with a biocontrol agent for ShB management. Streptomyces padanus PMS-702 showed a great antagonistic activity against R. solani. Fungichromin produced by S. padanus PMS-702, at 3.07 mg/l inhibited 50% mycelial growth, caused leakage of cytoplasm, and inhibited the formation of infection structures of R. solani. Fungichromin could reach to 802 mg/l when S. padanus PMS-702 was cultured in MACC broth for 6 days. Addition of 0.5% S. padanus PMS-702 broth into soil decreased the survival rate of the pathogen compared to the control. Soil amended with 0.5% S. padanus broth and 0.5% tea seed pomace resulted in the death of R. solani mycelia in the infested rice straws, and the germination of sclerotia was inhibited 21 days after treatment. Greenhouse trials revealed that S. padanus cultured in soybean meal-glucose (SMGC-2) medium after mixing with different surfactants could enhance its efficacy for inhibiting the pathogen. Of six surfactants tested, the addition of 2% tea saponin was the most effective in suppressing the pathogen. S. padanus broth after being fermented in SMGC-2, mixed with 2% tea saponin, diluted 100 fold, and sprayed onto rice plants significantly reduced ShB disease severity. Thus, S. padanus PMS-702 is an effective biocontrol agent. The efficacy of S. padanus PMS-702 for disease control could be improved through formulation.

• 한국응용곤충학회지
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• 제13권3호
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• pp.145-149
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• 1974