• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.245-257
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• 2023

The representative crop in the Republic of Korea, rice, is cultivated over extensive areas every year, which resulting in reduced resistance to pests and diseases. One of the major rice diseases, rice blast disease, can lead to a significant decrease in yields when it occurs on a large scale, necessitating early detection and effective control of rice blast disease. Drone-based crop monitoring techniques are valuable for detecting abnormal growth, but frequent image capture for potential rice blast disease occurrences can consume significant labor and resources. The purpose of this study is to early detect rice blast disease using remote sensing data, such as drone and satellite images, along with weather data. Satellite images was helpful in identifying rice cultivation fields. Effective detection of paddy fields was achieved by utilizing vegetation and water indices. Subsequently, air temperature, relative humidity, and number of rainy days were used to calculate the risk of rice blast disease occurrence. An increase in the risk of disease occurrence implies a higher likelihood of disease development, and drone measurements perform at this time. Spectral reflectance changes in the red and near-infrared wavelength regions were observed at the locations where rice blast disease occurred. Clusters with low vegetation index values were observed at locations where rice blast disease occurred, and the time series data for drone images allowed for tracking the spread of the disease from these points. Finally, drone images captured before harvesting was used to generate spatial information on the incidence of rice blast disease in each field.

• Research in Plant Disease
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• v.21 no.2
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• pp.103-106
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• 2015

Isolates of the rice blast fungus show a range of tissue-specificities infecting leaves, nodes, neck and panicles. Although neck and panicle blast cause significantly greater yield losses than the leaf blast, virulence tests of the blast isolates have been performed only rice leaves instead of neck and panicles. In this study, we have developed a virulence test method for neck and panicle blast. We selected three representative isolates from each of leaf, neck, and panicle blast. We observed that severe disease lesions developed on the neck and the panicles when the infected rice plants were incubated in a dew chamber for 48 h instead of 24 h when tested on leaves. Unlike the leaf blast, a typical lesion on the neck and panicles appeared after 14 days post-infection as opposed to 7 days with leaf blast. This method will be applied to examine tissue-specificity of the rice blast fungus isolates.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.127-127
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• 2003

벼 도열병 저항성 조절과정을 연구하는 효율적인 방법은 돌연변이를 분리하여 해당유전자를 분석하는 것이다. 이를 위하여 벼에서 제조된 4가지 돌연변이 집단을 이용하여 도열병 저항성 돌연변이를 분리하였다. 실험재료로는 1) fast neturon을 처리하여 제조된 Moroberekan 2,000 라인, 2)T-DNA의 형질전환에 의해서 제조된 화영 1,000 라인, 3)DEB처리에 의해서 제조된 RIL260 3,000라인, 4) gamma ray 처리에 의해서 제조된 상해향혈나 10,000 라인 등이 사용되었다. 병 저항성이 감소된 돌연변이의 분리를 위하여 재료로 사용된 벼 품종과 비친화적 상호작용을 보이는 균주의 포자를 2-3주된 벼 잎에 직접 살포하는 방법을 이용하였다. 균주 접종 7 일 후에 blast lesion을 형성하거나 lesion mimic 표현형을 보이는 돌연변이 등 병저항성이 감소된 라인을 선별하였다. 현재까지 1) Moroberakan 5 라인, 2) 화영 4 라인, 3) RIL260 1 라인 등이 선별되었다. 이와 함께 병저항성이 현저히 증가된 돌연 변이를 선별하기 위하여 친화적인 균주를 사용한 실험에서는 상해향렬나 2 라인이 선별되었다. 선별된 돌연변이는 벼 도열병 저항성 유전자의 분리 및 저항성 조절기작을 연구하는데 효과적으로 사용될 것이다.

• Research in Plant Disease
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• v.22 no.3
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• pp.202-207
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• 2016

Rice bacterial blight and blast are devastating rice diseases in worldwide. Riboflavin, vitamin B2, is an essential nutrient for human health, and is known to be as a growth regulator and as a plant defense activator against pathogens in plants. In this study, we investigated possibility of increasing internal vitamin B contents and inducing resistances against rice diseases by external foliar application of a riboflavin-based formulator called BioDoctor. In planta bioassay indicated that pretreatment of the foliar application of 1,000-fold or 500-fold diluted BioDoctor significantly induced disease resistance against rice blast and bacterial blight. In addition, about four fold higher levels of riboflavin contents were detected in the BioDoctor treated rice grain and stem compared to those of untreated rice. Our results indicated that foliar application of the riboflavin has a great potential to control plant diseases and to enhance internal vitamin contents in rice.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.9 no.2
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• pp.66-73
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• 1988

우리나라에서 조사된 벼의 종자전염성 곰팡이는 35종이나 된다. 벼의 종자는 이들 병원체에 의해 감염되어 있다. 종자소득을 실시하면 모잘록병은 물론 도열병, 깨씨무늬병, 키다리병, 이삭마름병등 종자전염성 병의 발생을 미리 막을 수 있다.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.394-400
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• 2008

Blast resistance of one hundred and thirty-one rice cultivars bred in Korea was tested with thirty Korean isolates and twenty-two Philippines isolates using three screening methods. In the blast nursery conducted in Korea and in the Philippines, average disease index of rice cultivars were 4.6 and 2.2, respectively. Seventy-nine cultivars showed different resistance reaction in Korea and in the Philippines, and 19 cultivars showed the same resistant reaction in two locations. In the seedling test, Korean blast isolates displayed different levels of virulence. 93-093, a Korean isolate, was compatible with 90 cultivars whereas 97-057 showed a compatible reaction with 13 cultivars. Twenty-three cultivars showed high level of resistance against Korean and Philippines isolates but Chucheongbyeo, Heugnambyeo, and Manmibyeo showed susceptible reaction to all blast isolates. Through the sequential planting test in Korea and in the Philippines, Palgongbyeo and Seomjinbyeo displayed durable resistance, and Nagdongbyeo and Gihobyeo showed high level of disease infection over the planting time. These results indicate that blast isolates collected in two countries have different genetic background and number of compatible isolates should be considered in definition the durability of rice cultivar to rice blast.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.345-350
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• 1996

작물시험장 등 한국의 3개 기관에서 육성하여 1996년도 신품종으로 명명된 다산벼 등 10개 품종과 수원400호 등 6계통을 공시하여 1993년부터 1995년까지 3년동안 이천 등 4개 지역에서 도열병에 대한 발병정도 차이를 검토하였다. 밭못자리검정 결과, 다산벼, 안산벼 빛 남천벼는 발병정도 0∼7로 중도저항성 반응을 보였다. 본답에서의 잎도열병은 다산벼, 안산벼, 남천벼 일미벼 및 밀양123호에서는 전혀 발생되지 않았고, 이삭도열병 발생은 다산벼 0.7%, 안산벼 및 남천벼 1.3%, 수원400호 1.6%를 제외하고는 지역과 연도에 따라 발병정도가 달랐다. 특히 화신벼, 향남벼, 삼천벼, 일미벼 및 중화벼의 경우 이천, 춘천과 나주에서는 이삭도열병이 경미하거나 전혀 발병되지 않았으나, 1995년도 제천에서 16.1∼55.6%로 지역간, 연차간 발병정도의 차이가 심하였다. 또한 도열병균의 레이스 분포상황은 지역별로 다양하였으나 특히 이천 및 제천에서 최근에 판별된 레이스 KI-197의 분포비율이 높았다.

• Research in Plant Disease
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• v.28 no.3
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• pp.113-121
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• 2022

Rice blast is a major plant disease that occurs worldwide and significantly reduces rice yields. Rice blast disease occurs periodically in Korea, causing significant socio-economic damage due to the unique status of rice as a major staple crop. A disease outbreak prediction system is required for preventing rice blast disease. Epidemiological investigations of disease outbreaks can aid in decision-making for plant disease management. Currently, plant disease prediction and epidemiological investigations are mainly based on quantitatively measurable, structured data such as crop growth and damage, weather, and other environmental factors. On the other hand, text data related to the occurrence of plant diseases are accumulated along with the structured data. However, epidemiological investigations using these unstructured data have not been conducted. The useful information extracted using unstructured data can be used for more effective plant disease management. This study analyzed news articles related to the rice blast disease through text mining to investigate the years and provinces where rice blast disease occurred most in Korea. Moreover, the average temperature, total precipitation, sunshine hours, and supplied rice varieties in the regions were also analyzed. Through these data, it was estimated that the primary causes of the nationwide outbreak in 2020 and the major outbreak in Jeonbuk region in 2021 were meteorological factors. These results obtained through text mining can be combined with deep learning technology to be used as a tool to investigate the epidemiology of rice blast disease in the future.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.339-344
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• 2005

Rice blast, which is caused by the fungus Magnaporthe grisea, is one of the most destructive diseases of rice. To identify genes involving in the signal transduction pathways that mediate rice blast resistance, we screened over 2,000 mutant lines of a highly resistant variety RIL260 that were generated by using a DEB (1, 3-Butadiene diepoxide) treatment method. In the mutant population, the frequency of albino plants was 6.7%, indicating that this population has a high frequency of mutations in the genome. The primary screening identified 29 mutant plants that exhibit a complete or partial loss of the resistance to rice blast. Among them, M5465, the most susceptible line, was subsequently examined by DNA gel-blot experiments using DNA molecular markers of Pi5(t) that has been previously identified as a durable resistance locus in RIL260. The result revealed that a large deletion and rearrangement of genomic DNA occurred in the Pi5(t) locus. The results suggest that DEB can be used as an efficient mutagen to induce large scale mutations in the rice genome. The isolated mutants should be useful for elucidating the Pi5(t)-mediated signaling pathways of rice blast resistance.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.313-319
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• 2007

Nine plant growth regulators (PGRs) were tested for in vivo antifungal activities against on rice blast. They showed higher in vivo antifungal activities when they were applied on rice plants by soil drench rather than foliar spray. Except for 2,4-D at $500\;{\mu}g\;mL^{-1}$, the others showed a very low or no activity against the disease in foliar spray applications. In contrast, 2,4-D, indole butyric acid (IBA) and triiodobenzoic acid, at $500\;{\mu}g\;mL^{-1}$, showed control values of 98.9, 97.8 and 88.9% in soil drench applications. Furthermore, the control activity of IBA was dependent on its concentration against rice blast; IBA suppressed the development of rice blast by 71.7% at $125\;{\mu}g\;mL^{-1}$ and 85.8% at $250\;{\mu}g\;mL^{-1}$. IBA also controlled the development of rice blast on adult plants by 63.9% at a dosage of 2.56 kg/10a. The results revealed that IBA has a good activity against rice blast when it is applied by soil drench.