• The Plant Pathology Journal
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• v.16 no.4
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• pp.236-241
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• 2000

A selective agar medium was developed and tested for the isolation of Acidovorax avenae subsp. avenae, the causal bacterial pathogen of bacterial brown stripe, from rice seeds. The new selective agar medium, designated sorbitol pyroglutamic acid agar (SPA) medium, contained 0.5 g of $K_2$HPO$_4$, 3.0 g of Na$_2$HPO$_4$, 2.0 g of D-sorbitol, 0.2 g of L-pyroglutamic acid, 10.0 $m\ell$ of tween 80, 40.0 mg of victoria blue B, 15.0 g of agar, 150.0 mg of ampicillin and 25.0 mg of vancomycin per litter. Colonies of A. avenae subsp. avenae on SPA medium were smooth, round, convex, shiny, blue and 1.5-2.0 mm in diameter 4 days after incubation at 28$^{\circ}C$. Blue colored colony having dark blue zone was typical type of A. avenae subsp. avenae colonies on the medium. Mean recovery of 8 isolates of A. avenae subsp. avenae on the selective SPA medium was 95.8% in comparison to that on KB medium. The saprophytic bacteria were reduced to 97.9% on SPA medium compared to those on KB medium. Most of other rice seedborne bacteria as well as reported pathogenic bacteria were failed to grow on SPA medium. This medium was highly selective for recovering A. avenae subsp. avenae from rice seed samples, and it could be used to enhance the recovery of this bacterium from rice seed samples, which may be contaminated with large numbers of competing microorganisms.

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.319-324
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• 1994

The monoxenic culture of the fungivorous nematode, Aphelenchus avenae, was applied for the control of soil-borne ginseng pathogens such as Fusarium solani and Rhizoctonia solani. Fungivorous nematode populations were measured in a field to examine relationships between the nematode populations and suppression of ginseng root diseases. Inoculation of A. avenae (5000 nematodes per petri-dish) reduced the colonization of the Fusarium mycelium on root discs of ginseng and carrot by 80.0% and 60.5%, respectively. A. avenae also significantly reduced the occurrence of damping-off of ginseng by R. solani pathogenic to ginseng, and no plant damage by the nematode was noted. In a 3-year-old ginseng field infested with Cylindrocarpon destructans, plant missing caused by root rot positively correlated to the density of potato rot nematode, Ditylenchus destructor, but it was reduced with the population of A. avenae, suggesting that A. avenae might inhibit the occurrence of ginseng root rot.

• Plant Disease and Agriculture
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• v.5 no.2
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• pp.69-76
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• 1999

Acidovorax avenae subsp. avenae is the causal pathogen of several hosts including oats corn foxtail millet wheatgrass sugarcane and rice. The pathogen is a seedborne pathogen of rice and known to occur widely in rice growing countries. The pathogen cause inhibition of germination brown stripe on the leaf curling of the leaf sheath and abnormal elongation of the mesocotyl of irce. Bacterial colonies grow slowly and are convex circular and creamy with tan to brown center. The causal baterium is Gram-negative and rod shape with a single polar flagellum Nonfluorescence poly-$\beta$-hydroxybutyrate accumulation and precipitate formation around the colony on the medium are useful in the differentiation of this bacterium from other subspecies of A. avenae as well as nonfluorescent bacteria pathogenic to rice. This bacterium has belonged to the genus of Psdeudomonas but recently was transferred to the new genus Acidovorax on the basis of bacteriological and molecular biological data. However the difference of biochemical characteristics protein profile of the cell and host range among strains should be more clarified. To develop an effective control strategy for this disease understanding of detailed life cycle of the disease ritical environmental factors affecting disease development on each host and relationship to grain discoloration of rice are prerequisite. Although the affected area has been world-widely reported there is on recent progress on the understanding of the bacteriological and ecological characteristics of the causal bacterium and control means of the disease.

• The Plant Pathology Journal
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• v.32 no.6
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• pp.575-579
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• 2016

Burkholderia glumae (bacterial grain rot), Xanthomonas oryzae pv. oryzae (bacterial leaf blight), and Acidovorax avenae subsp. avenae (bacterial brown stripe) are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae, and transposase A gene sequence for X. oryzae pv. oryzae, three sets of primers had been designed to produce 402 bp for B. glumae, 490 bp for X. oryzae, and 290 bp for A. avenae subsp. avenae with the $63^{\circ}C$ as an optimum annealing temperature. Samples collected from naturally infected fields were detected with two bacteria, B. glumae and A. avenae subsp. avenae but X. oryzae pv. oryzae was not detected. This assay can be used to identify pathogens directly from infected seeds, and will be an effective tool for the identification of the three pathogens in rice plants.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.459-466
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• 2018

In January 2017, discolored black oat seeds were found in the storage depot of a farmhouse in Jeongeup. Pyrenophora sp. was detected in 45% of the oat seeds surveyed. All Pyrenophora isolates obtained from the seeds were identified as Pyrenophora avenae based on the sequences of internal transcribed spacer (ITS) rDNA regions and glyceraldehyde 3-phosphate dehydrogenase (GPDH) gene and validated by morphological and cultural characterization. A phylogenetic tree constructed using the ITS and GPDH sequences showed that the Korean isolates of P. avenae comprise of four genetically distinct groups. Pathogenicity test validated that the fungus is an infectious agent responsible for discolored black seeds and leaf blotch in oat plants. This is the first study report that P. avenae causes leaf blotch disease of oat in Korea.

• Research in Plant Disease
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• v.18 no.3
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• pp.236-239
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• 2012

In July, 2009, proso millet (Panicum miliaceum), which showing the bacterial brown stripes on leaf sheaths, was collected in Miryang in Korea. Symptoms were systemic brown necrotic stripe lesions on the leaf sheaths and stems, and these symptoms were found in the entire field. The causal agent isolated from symptomatic plants was identified as an Acidovorax avenae subsp. avenae, based on its biochemical and physiological characteristics and also confirmed by the Biolog data and 16S rRNA gene sequence analysis. Also it caused hypersensitive response (HR) when it was inoculated onto the tobacco and tomato. It caused similar symptoms when inoculated onto proso millet. This is the first report of A. avenae subsp. avenae, the causal agent of bacterial brown stripe of the proso millet in Korea.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.38-43
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• 1985

A bacterial brown stripe disease new to Korea was noted for the first time on rice seedlings grown in the nursery pots and in a field nursery. Artificial hypodermic injection and pricking inoculation with isolates obtained from lesions of naturally infected plants produced symptoms similar to those occurring under natural condition. Among eleven species of ten genera of gramineous plants Echinochloa crusgalli, Digitaria sanguinalis and Setaria viridis were the new hosts for the pathogen. On the basis of bacteriological and biochemical tests of isolates from infected rice seedlings, the causal bacterium is considered to be Pseudomonas avenae Manns.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1401-1409
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• 2015

The aim of this study was to develop a SYBR Green-based real-time PCR assay for the rapid, specific, and sensitive detection of Acidovorax avenae subsp. citrulli, which causes bacterial fruit blotch (BFB), a serious disease of cucurbit plants. The molecular and serological methods currently available for the detection of this pathogen are insufficiently sensitive and specific. Thus, a novel SYBR Green-based real-time PCR assay targeting the YD-repeat protein gene of A. avenae subsp. citrulli was developed. The specificity of the primer set was evaluated using DNA purified from 6 isolates of A. avenae subsp. citrulli, 7 other Acidovorax species, and 22 of non-targeted strains, including pathogens and non-pathogens. The AC158F/R primer set amplified a single band of the expected size from genomic DNA obtained from the A. avenae subsp. citrulli strains but not from the genomic DNA of other Acidovorax species, including that of other bacterial genera. Using this assay, it was possible to detect at least one genomeequivalents of the cloned amplified target DNA using 5 × 10⁰ fg/µl of purified genomic DNA per reaction or using a calibrated cell suspension, with 6.5 colony-forming units per reaction being employed. In addition, this assay is a highly sensitive and reliable method for identifying and quantifying the target pathogen in infected samples that does not require DNA extraction. Therefore, we suggest that this approach is suitable for the rapid and efficient diagnosis of A. avenae subsp. citrulli contaminations of seed lots and plants.

• Korean Journal Plant Pathology
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• v.3 no.4
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• pp.300.1-300.1
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• 1987

• Research in Plant Disease
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• v.12 no.3
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• pp.185-188
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• 2006

In September and October 2005, melons(Cucumis melo L.) from the commercial greenhouses in Naju and Gwangju exhibited severe foliar necrosis and fruit rot. Leaf symptoms initially appeared as V-shaped, necrotic lesions and extending to the midrib. Symptoms on the fruit were occurred randomly as necrotic and sunken spots. Two isolates from diseased leaves and fruits were identified as Acidovorax avenae subsp. citrulli on the basis of bacteriological and genetic characteristics. Pathogenicity of the isolates was confirmed by inoculating on 3-week-old melon and cucumber seedlings. This is the first report of bacterial fruit blotch of melon in Korea.