• Applied Biological Chemistry
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• v.48 no.1
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• pp.48-52
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• 2005

Six stains of plant growth promoting rhizobacteria were selected through germinating seed assay and root colonization assay. Among them, SKU-78 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 60% reduction of bacterial wilt disease compared with the control. It was suggested that SKU-78 strain activated the host defense systems in plants, based on lack of direct antibiosis against pathogen. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, SKU-78 stain was identified as Bacillus sp. SKU-78.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.97-103
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• 1992

KB 101 is a bacterial wilt(Pseudomonas solanaceamm E.F. Smith) and black shank (Phytophthora nicotianae Breda de Haan Var. nicotianae Waterhouse) resistant cultivar of burley tobacco (Nicotiana tabacum L.) KB 101 was developed by the Korea Ginseng&Tobacco Research Institute, and released in 1987. KB 101 was developed from a single plant selection in the F2 generation derived from the double cross, [(Burley 21X Burley 37) X (Burley 64X Ky 16)]. Burley 37 and Burley 64 were the source of resistance to bacterial wilt and black shank. Yield trials were conducted in the Fs through F6 generations at the four Exp. Stn. of Korea Ginseng &Tobacco Research Institute as JB 7705-1. On-farm yield trials were conducted in the F7 through F9 generations at the 45 locations of burley tobacco growing area from 1984 to 1986 as KB 101. KB 101 has an erect growth habit similar to that of Burley 21: plant size is larger and has more leaves than those of Burley 21. It is late maturing cultivar that flowers approximately 3 days later than Burley 21. The physical characteristics and chemical composition of KB 101 were similar to those of Burley 21.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.149-155
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• 1989

This study was conducted to obtain the breeding information for the leaf breakdown, and correlation coefficients between leaf breakdown and some agronomic characters in flue-cured tobacco at Taegu Experiment Station, Korea Ginseng & Tobacco Research Institute. NC 95 and NC 2326 were used as parents. The bulk method procedure was used from the F2 to the F4 generations, 54 plants were selected among F4, and 11 lines were selected among 54 F5 which based on high resistance to bacterial wilt compared with NC2326. The entries were composed of parents and 11 F6 advanced lines, and designed in randomized block with 3 replications. Plant seedlings were transplanted in 16 April. The number of breakdown leaf were investigated at flowering stage, 18 June. There were significant difference between NC 95 and NC 2326 for the number of breakdown leaf, number and weight of ground suckers, days to flower, yield and resistance to bacterial wilt, and similar results were appeared among lines. Estimated heritability in the broad-sense ranged from 59.3% to 87.4% for all characters. Most of genetic correlations were higher than phenotypic coefficients between characters. Number of breakdown leaf was positively correlated with days to flower, the number and weight of ground suckers, while it was negative to yield. One line among 11 had few breakdown leaf, low producted ground suckers and high resistance to bacterial wilt. Above results suggest that the number and weight of ground suckers can be use as a selection criterion for leaf breakdown even under the condition without leaf breakdown.

• Research in Plant Disease
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• v.13 no.1
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• pp.1-5
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• 2007

Major diseases of tobacco and farmer's control practices were surveyed in the Kyeongbuk province area from 2005 to 2006. Mosaic caused by potato virus Y and bacterial wilt caused by Ralstonia solanacearum were most severe during the harvest season. Compared with the disease occurrence of ten years ago, the damage by tobacco mosaic virus reduced but bacterial wilt increased. These changes in the disease occurrences may probably be due to releasing the resistant tobacco cultivar to the mosaic virus but susceptible to the bacterial wilt pathogen. More than thirty percentage of the farmers have misused fungicides and also have applied the continuous mono-cropping system for more than ten years, and have chosen the incorrect crops for the rotation.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.212-217
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• 2019

Bacterial wilt caused by Ralstonia solanacearum is a major disease that affects tomato plants widely. R. solanacearum is a soil born pathogen which limits the disease control measures. Therefore, breeding of resistant tomato variety to this disease is important. To identify the susceptible variety, degree of disease resistance has to be determined. In this study, micro sap flow sensor is used for accurate prediction of resistant degree. The sensor is designed to measure sap flow and water use in stems of plants. Using this sensor, the susceptibility to bacterial wilt disease can be identified two to three days prior to the onsite of symptoms after innoculation of R. solanacearum. Thus, this find of diagnosis approach can be utilized for the early detection of bacterial wilt disease.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.1-11
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• 2001

Climate in the year of 2000 was characterized as a long severe drought in tile spring, unusually high and low temperature in summer, two times of typoons, and floods by heavy rains in fall. Rice leaf and panicle blast and bacterial grain rot occurred severely comparing with 1999 and Bipolaris leaf spot spread over tile country. Phytophthora blight and anthracnose in red-pepper became epidemic especially in the late season causing severe yield losses. Tomato fusaruim wilt, CGMMV, powdery mildew, and sudden wilt syndrom of cucurbits and strawberry powdery mildew were also severe in 2000. In garlic, sclerotium rot occurred severely mainly due to the frequent rainfalls in planting time and much snowfalls in 1999's winter. Spring potato had severe infection of viruses due to a long spring drought, and fall potato had high incidence of bacterial soft rot and bacterial wilt due to fall floods by heavy rains. In sweet potato fusarium wilt was the most severe as in other year. Disease incidence of apple and pear trees was rotatively mild compared with previous years. In wheat and barley, Gibberella petch rarely occurred because of spring drought.

• The Plant Pathology Journal
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• v.34 no.2
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• pp.104-112
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• 2018

Accurate and rapid detection of bacterial plant pathogen is the first step toward disease management and prevention of pathogen spread. Bacterial plant pathogens Clavibacter michiganensis subsp. nebraskensis (Cmn), Pantoea stewartii subsp. stewartii (Pss), and Rathayibacter tritici (Rt) cause Goss's bacterial wilt and blight of maize, Stewart's wilt of maize and spike blight of wheat and barley, respectively. The bacterial diseases are not globally distributed and not present in Korea. This study adopted comparative genomics approach and aimed to develop specific primer pairs to detect these three bacterial pathogens. Genome comparison among target pathogens and their closely related bacterial species generated 15-20 candidate primer pairs per bacterial pathogen. The primer pairs were assessed by a conventional PCR for specificity against 33 species of Clavibacter, Pantoea, Rathayibacter, Pectobacterium, Curtobacterium. The investigation for specificity and sensitivity of the primer pairs allowed final selection of one or two primer pairs per bacterial pathogens. In our assay condition, a detection limit of Pss and Cmn was $2pg/{\mu}l$ of genomic DNA per PCR reaction, while the detection limit for Rt primers was higher. The selected primers could also detect bacterial cells up to $8.8{\times}10^3cfu$ to $7.84{\times}10^4cfu$ per gram of grain seeds artificially infected with corresponding bacterial pathogens. The primer pairs and PCR assay developed in this study provide an accurate and rapid detection method for three bacterial pathogens of grains, which can be used to investigate bacteria contamination in grain seeds and to ultimately prevent pathogen dissemination over countries.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.61-63
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• 1999

Bacterial soft rot was observed on radish grown in Hongcheon, Kanwon-Do, Korea. The soft rot symptoms began as small water-soaked lesions. The water-soaked lesions enlarged rapidly in roots and produced a foul odor. When roots were affected in the field, the shoots also became infected and watery, causing infected plants to wilt, disorganize, and die. The causal organism was isolated from the lesions, and the identified as Erwinia chrysanthemi based on the morphological, physiological and biochemical characteristics. E. chrysanthemi is first described bacterium which causes bacterial soft rot on radish in Korea.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.548-550
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• 1998

Bacterial soft rot caused damage to beets massively grown in Pyungchang, Kangwon province, Korea. The affected roots and stems became cream colored and slimy, and turned black, causing the plants to become wilt and die. The casual organism isolated from the infected plants was identified as Erinia carotovora subsp. carotovora based on physiological and biochemical characteristic, and the results of the Biolog program (Biolog Inc., U.S.A.). E. carotovora subsp. carotovora is the first discribed bacterium which causes bacterial soft rot on beet in Korea.

• The Plant Pathology Journal
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• v.35 no.2
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• pp.137-148
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• 2019

In search of an effective biological control agent against the tomato pathogen Fusarium oxysporum f. sp. lycopersici, rhizospheric soil samples were collected from eight agro-ecological zones of Bangladesh. Among the bacteria isolated from soil, 24 isolates were randomly selected and evaluated for their antagonistic activity against F. oxysporum f. sp. lycopersici. The two promising antagonistic isolates were identified as Brevundimonas olei and Bacillus methylotrophicus based on morphological, biochemical and molecular characteristics. These two isolates were evaluated for their biocontrol activity and growth promotion of two tomato cultivars (cv. Pusa Rubi and Ratan) for two consecutive years. Treatment of Pusa Rubi and Ratan seeds with B. olei prior to inoculation of pathogen caused 44.99% and 41.91% disease inhibition respectively compared to the untreated but pathogen-inoculated control plants. However, treatment of Pusa Rubi and Ratan seeds with B. methylotrophicus caused 24.99% and 39.20% disease inhibition respectively. Furthermore, both the isolates enhanced the growth of tomato plants. The study revealed that these indigenous bacterial isolates can be used as an effective biocontrol agent against Fusarium wilt of tomato.