• Applied Biological Chemistry
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• v.6
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• pp.37-43
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• 1965

8-Hydroxyquinoline, known to have the therapeutic effect to fusarium; and to diminish the amount of evaporation because of reducing the size of the stomata, and a new compound, phenylmercuric 8-oxyquinolinate, were synthesized. The fungicidal effect and diminishing effect of evaporation in phenylmercuric 8-oxyquinolinate were studied and the results are as follows. 1) 8-Hydroxyquinoline(m.p. $74{\sim}75^{\circ}C$, white needle crystalline) was synthesized by Skraup's method, 2) Phenylmercuric 8-oxyquinolinate(m.p. $159{\sim}160^{\circ}C$, yellowish brown needle crystalline) was synthesized by reacting phenylmercuricacetate to 8-hydroxyquinoline. 3) The orders of the fungicidal effects are; a) To Cochliobolus miyabeanus P.M.A.

• The Korean Journal of Mycology
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• v.47 no.3
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• pp.259-269
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• 2019

Brown spot and sheath rot of rice are caused by fungal pathogens such as Curvularia lunata, Cochliobolus miyabeanus, and Sarocladium oryzae, and cause losses such as reduced rice yield and quality, which is an enormous problem with serious long-term effects. To search biological control agents of phytopathogenic fungi, five kinds of useful Bacillus-like isolates which are excellent in extracellular enzyme activity and produce siderophore were selected from paddy soil of Sunchang in Korea. The selected isolates were tested for excellent antifungal activity against three of the phytopathogenic fungi that frequently occur in rice, and JSRB 177 strain had the most excellent antifungal activity. Based on the experimental results, JSRB 177 is finally selected as a candidate for biological control and identified to Bacillus subtilis through 16S rRNA sequence analysis. In addition, physiological characteristics of JSRB 177 confirmed by analysis of carbohydrate fermentation patterns and enzyme production ability. Based on the above results, JSRB 177 is expected to be used as a biological control agent for the rice pathogenic fungi. In the future, further studies related to industrialization such as port test and establishment of mass production process are needed.

• Research in Plant Disease
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• v.15 no.1
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• pp.41-45
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• 2009

In order to study a relationship between soil nutrients and rice brown spot occurrence, paddy field soils, rice grains and straws collected from different paddy fields with different disease degrees of brown spots were analyzed for inorganic nutrients. Brown spot was prevalent in the rice grown in nutrient-deficient soils, which is especially low in macronutrient elements (phosphoric acid, potassium, silicic acids) and micronurients (calcium, magnesium). The soil, however, was high in sodium while organic nutrients and pH level were similar to others. The rice straws with severe brown spot were low in inorganics such as ferrous, copper, T-N, and $P_{2}O_{5}$ while the rice grains with brown spot were low in ferrous, MgO, Zn, and Mn. In the analysis of field type and nitrogen level, the highest disease severity was found in sandy-type field soil, followed by salty-type field soil and disease severity decreased as application level of nitrogen fertilizer increased. As a summary, the most important factor for effective brown spot control in rice is maintenance of proper nutrients in sandy-type field and control of sodium level in salty-type field soil.