• 한국육종학회지
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• 제43권4호
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• pp.241-251
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• 2011

Bacterial blight(BB) caused by Xanthomonas oryzae pv. oryzae(Xoo) is one of the most economically destructive bacterial diseases of rice in worldwide. Utilization of resistant cultivars carrying resistant gene(s) is relatively an effect method to control this disease. About 34 resistant genes for BB resistance have been identified in many countries. Among them, Xa1 and Xa3 genes against bacterial blight have been incorporated into improved korean japonica rice varieties. Now, Ilmi carrying Xa1 gene and severial cultivars carrying Xa3 gene are widely grown in our country. In recent year, xa5, Xa21 and Xa23 genes are using in rice breeding programs for japonica resistant cultivars to bacterial blight. Resistant cultivars incorporated with a diverse single gene and two, three, or the more major gene necessite in the future.

• The Plant Pathology Journal
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• 제38권5호
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• pp.490-502
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• 2022

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight (BLB) disease in rice (Oryza sativa L.) and it is among the most destructive pathogen responsible for severe yield losses. Potential bacterial biocontrol agents (BCAs) with plant growth promotion (PGP) abilities can be applied to better manage the BLB disease and increase crop yield, compared to current conventional practices. Thus, this study aimed to isolate, screen, and identify potential BCAs with PGP abilities. Isolation of the BCAs was performed from internal plant tissues and rhizosphere soil of healthy and Xoo-infected rice. A total of 18 bacterial strains were successfully screened for in vitro antagonistic ability against Xoo, siderophore production and PGP potentials. Among the bacterial strains, 3 endophytes, Bacillus sp. strain USML8, Bacillus sp. strain USML9, and Bacillus sp. strain USMR1 which were isolated from diseased plants harbored the BCA traits and significantly reduced leaf blight severity of rice. Simultaneously, the endophytic BCAs also possessed plant growth promoting traits and were able to enhance rice growth. Application of the selected endophytes (BCAs-PGP) at the early growth stage of rice exhibited potential in suppressing BLB disease and promoting rice growth.

• 한국육종학회지
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• 제43권5호
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• pp.383-390
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• 2011

Near-isogenic lines (NILs) carrying bacterial blight resistance genes (Xa4, xa5 and Xa21) were developed in japonica rice using Suweon345 as genetic background. NILs were selected by gene specific DNA markers and inoculation of K1 or K3a race. NILs conferring Xa4 were resistant to K1, K2, K3, and moderately resistant to K3a. NILs conferring xa5 were resistant to K1, K2, K3, and K3a. NILs having Xa21 were susceptible to K1, while resistant to K2, K3 and K3a. Target genes of NILs with the genetic background of Suweon345 were also confirmed by using eleven Philippines races and International Rice Bacterial Blight (IRBB) NILs carrying Xa4, xa5 and Xa21. All NILs had no significant difference from their recurrent parents in the major agronomic traits except for panicle length and brown rice 1,000 grain weight. Heading date of NILs ranged from Aug. 10 to Aug. 11, which was similar to that of recurrent parent, Suweon345. Culm length, number of grains per panicle and ratio of ripened grain of NILs were similar to those of Suweon345. Milled rice of NILs was ranged from 4.82 to 4.93MT/ha. These NILs will be useful for improving resistance to K3a race of bacterial blight pathogens in Korean japonica cultivars.

• Journal of Applied Biological Chemistry
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• 제59권2호
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• pp.149-154
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• 2016

An endophytic bacterial strain was isolated from kimchi, a Korean traditional fermented Brassica campestris and identified as Bacillus subtilis MJMP2 based on the 16S rRNA sequence. This strain showed strong antagonistic activity against Xanthomonas oryzae pv. oryzae (Xoo) KACC10331, the pathogen of bacterial rice blight disease, as well as activity against some other rice phytopathogenic fungi. The active compound was purified through size-exclusion chromatography and preparative High-performance liquid chromatography. The molecular weight was determined as m/z 1043 by mass spectroscopy, which is identical to that of iturin A. Furthermore, a crude extract from the culture supernatant of Bacillus subtilis MJMP2 showed inhibitory activity against rice blight disease in both a rice leaf explant assay and a pot assay. The crude extract also enhanced the length of roots of Arabidopsis thaliana. These results suggest that the strain Bacillus subtilis MJMP2 could be used as a biological agent to control rice blight disease.

• The Plant Pathology Journal
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• 제17권5호
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• pp.249-256
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• 2001

Xanthomonas axonopodis pv. glycines 8ra produces a bacteriocin called glycinecinA, which specifically inhibits the growth of bacteria belonging to Xanthomonas species. GlycinecinA was produced by culturing Escherichia coli DH5 containing biosynthetic genes for glycinecinA, and was tested for its control effect against X. vesicatoria on red pepper and X. oryzae pv. oryzae on rice. The bacteriocin activity was much higher in the cell extract than in the supernatant. It reached a maximum level at the stationary phase, ws maintained up to 2 months at room temperature and approximately 10 months at $4^{\circ}$. The optimum concentration of glycinecinA for the control in the greenhouse and in the field was 12,800 AU/ml. In this study, the activity of glycinecinA on rice and red pepper leaves continued for 7-8 days, during which the pathogen populations remained at low levels. Bacterial leaf spot of red pepper and bacterial leaf blight of rice were significantly reduced by the bacteriocin treatments. The control efficacy was as high as, or even higher than, the chemical treatment of copper hydroxide. These results suggest that the bacteriocin is a potential control agent for bacterial diseases.

• 한국육종학회지
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• 제49권3호
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• pp.235-244
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• 2017

'만백'은 농촌진흥청 국립식량과학원에서 벼흰잎마름병에 대한 저항성이 증진된 고품질 중만생 벼 품종을 개발하고자 육성되었다. 최고품질 중만생 벼 '호품'을 반복친으로하고 벼흰잎마름병 저항성 유전자가 집적된 육성계통 'SR30075'를 수여친으로 하여 작성된 여교배 $BC_1F_1$ 식물체를 약배양하여 계통육성과정, 생산력 검정시험 및 지역적응성 검정시험을 거쳐 육성되었다. '만백'은 벼흰잎마름병 저항성 유전자 Xa3와 xa5 두 개가 집적되어 있어 병원성이 강한 벼흰잎마름병 K3a 균계에 저항성이면서 국내 수집 16개 균주에도 모두 강한 광범위 저항성을 나타냈다. '만백'의 출수기는 평균 8월 19일로 '남평'보다 5일 늦은 중만생종이다. '만백'은 엽색이 진한 녹색을 띄며 간장이 '남평'보다 작은 단간 내도복 품종이다. 또한 수발아 내성을 가지고 있어 수발아에 대한 안정성 확보를 위한 육종소재로 활용될 수 있을 것으로 생각된다. 벼흰잎마름병 및 줄무늬잎마름병에는 저항성이나 도열병, 기타 바이러스병 및 해충에 대한 저항성은 없다. 쌀의 수량성은 '남평'과 비슷한 수준을 나타냈다. 쌀의 외관품위가 좋고 밥맛이 양호하여 벼흰잎마름병 저항성 품종의 품질 향상에 기여하였다. '만백'은 벼흰잎마름병에 대한 저항성이 증진된 고품질 벼 품종으로 벼흰잎마름병 발병상습지 재배에 접합하며 벼흰잎마름병 저항성 향상을 위한 육종사업에 활용되고 있다.

• 한국식물병리학회지
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• 제1권2호
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• pp.115-121
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• 1985

벼 흰빛잎마름병에 대한 새로운 포장 저항성 검정법을 모색하기 위하여 검정 식물체 접종법과 인접 식물체 접종법을 비교 검토하였다. 새로운 검정법인 검정 식물체 접종법에서는 포장 저항성 검정 식물체를 전엽접종한 발병엽으로부터 새로 출엽된 잎에 이차전염된 발병 엽면적율을 측정하였다. 검정 식물체 접종으로 검정된 포장 저항성 정도는 인접 식물체 접종 결과와 높은 상관이 인정되었으나 포장 저항성 정도는 검정 식물체 접종법에서 명확히 구분되었다. 공시한 33품종 중에서는 밀양 42호, 삼강벼, 태백벼, 한강찰벼, 섬진벼, 70 X-46, 중국 45호 등이 강한 포장 저항성을 보였다. 새로운 포장 저항성 검정법은 품종의 질적 저항성 및 포장 저항성을 동시에 검정할 수 있을 뿐만 아니라 다른 검정법에 비하여 노력과 포장 면적이 적게 들기 때문에 유용한 검정법으로 이용될 수 있을 것으로 생각된다.

• 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.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1236-1242
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• 2011

Xanthomonas oryzae pv. oryzae (Xoo) is the most devastating pathogen to Oryza sativa and has been shown to cause bacterial blight. Two bioactive compounds showing antimicrobial activities against Xoo strain KACC 10331 were isolated from a Streptomyces bottropensis strain. The ethyl acetate extract was fractionated on a Sephadex LH-20 column, and then purified by preparative HPLC. The purified compounds were identified as bottromycin A2 and dunaimycin D3S by HR/MS and $^1H$ NMR analyses. The MIC value against Xoo and the lowest concentration still capable of suppressing rice bacterial blight were 2 ${\mu}g$/ml and 16 ${\mu}g$/ml for bottromycin A2, and 64 ${\mu}g$/ml and 0.06 ${\mu}g$/ml for dunaimycin D3S, respectively. These two compounds were shown to exert different bioactivities in vitro and in rice leaf explants.

• 한국작물학회지
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• 제35권2호
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• pp.132-136
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• 1990

수도 흰잎마름병(Xanthomonas campestris pv. oryzae) 병원세균(K1)의 조직내에서의 증식과 이동 그리고 수공을 통해 추출되는 병원세균의 농도를 조사한 결과를 요약하면 다음과 같다. 1. 저항성 품종에서는 접종 3일후에 약 $10^3$cfu/$\textrm{cm}^2$로 12일까지 큰 변화가 없었으나 리병성 품종에서는 접종 6일에 약 $10^4$cfu/$\textrm{cm}^2$에서 접종 12일에는 약 $10^{8}$-$10^{9}$cfu/$\textrm{cm}^2$로 계속 증식하였다. 2. 병원세균의 접종부위로부터 상, 하향 이동속도 및 증식속도는 상향이동이 약간 빠른 경향이었으며 리병성 품종에서 빠른 증식과 이동속도를 보여 저항성과 밀접한 관계가 있었다. 3. 병원세균의 증식 및 이동은 생육시기에 따른 차이는 없었다. 4. 감염된 잎의 수공을 통해 나오는 병원세균의 농도는 조직내에서 병원세균의 증식 및 이동과 일치하였으며 저항성과도 밀접한 관계가 있었다.