• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.388-391
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• 2003

Tobacco mosaic virus (TMV), TMV-common strain, causes severe damage at growth, yield and leaf quality on flue-cured tobacco in Korea. Controlling TMV outbreak with cultivating practices and chemicals are limited, thus, the best way would be developing TMV resistant variety. A new flue-cured hybrid, KF118, was developed from a cross of maternal parent MSTC175 and TC853 at the Agro-tech. Research Group, KT＆G Central Research Institute. KF118 exhibited more vigorous growth characteristics in early stage than that of NC82, standard variety in Korea, while other characters were favorable to those of NC82, It is highly resistant to TMV and bacterial wilt(Ral-stonia solanacerum), and black shank(phytophthora parasitica var. nicotianae) is comparable to that of NC82. It should adapt well to the flue-cured production area, and can reduce premature flowering under unfavorable weather conditions. Yield of KF118 is 1 to 2% higher, and leaf quality is 4% higher than NC82. Fl hybrid, KF118, met acceptable standards for chemical and physical characteristics of cured leaf, and ranked high in good smoking taste by panel members in KT＆G.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.1
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• pp.69-75
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• 1994

A new flue - cured tobacco variety KF113 was developed by Nicotiana africana method from a cross of NC82 and Coker 347 at the Suwon Experiment Station. It was tested in the 0fficial Variety Test in 1991-1992 and the flue - cured Regional Farm Test in 1992. KFl13 flowers 4 days later than WC82 (standard variety in Korea) and its harvestable leaves are 2 more than those of NC82. The leaf type and shape of KFl13 resembles Coker 347. It has high resistance to bacterial wilt (Pseudomonas solanacearum) and black shank (Phytophthora parasitica var. nicotianae), and is susceptible to tobacco mosaic virus. It should adapt well to the flue - cured production area and can reduce premature flowering under unfavorable weather conditions. Yield of KFl13 is 5% higher than that of NC82, and nearly equal in value per kg compare with NC82. This variety met acceptable standards for chemical and physical characteristics of cured leaf and for smoking taste evaluated by panel members in Korea Ginseng & Tobacco Research Institute.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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• pp.41-48
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• 1995

Tobacco mosaic virus (TMV), TMV-common strain, causes severe damage on flue-cured tobacco in Korea. As the results, breeding programs were conducted to transfer the TMV resistance from NC567 to other cultivars. Advantage of F1, hybrid may not lie only in their heterotic value but also in directly combining of valuable dominant traits, e.g. for disease resistance, either in pairs or as groups already assembled in the two parents. A new TMV resistant flue-cured tobacco variety KF114 was developed from a cross as maternal parent MSNC567 and NC82 at the Suwon Experiment Station. KF114 was more vigorous growth characteristics in early stage than that of NC82, standard variety in Korea, and other characters were similar to those of NC82. It os high resistance to TMV, but bacterial wilt(Pseudomonas solanacerum) and black shank (Phytophthora parasitica var. nicotianae) is comparable to NC82. It should adapt well to the flue-cured production area and can reduce premature flowering under unfavorable weather conditions. Yield of KF114 is 1% to 5% higher, and nearly equal in value per KG compared with NC82. This variety, F1 hybrid, met acceptable standards for chemical and physical characteristics of cured leaf and high ranked good smoking taste by panel members in Korea Ginseng and Tobacco Research Institute.

• The Plant Pathology Journal
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• v.38 no.1
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• pp.33-45
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• 2022

To screen antagonistic fungi against plant pathogens, dual culture assay (DCA) and culture filtrate assay (CFA) were performed with unknown soil-born fungi. Among the different fungi isolated and screened from the soil, fungal isolate ANU-301 successfully inhibited growth of different plant pathogenic fungi, Colletotrichum acutatum, Alternaria alternata, and Fusarium oxysporum, in DCA and CFA. Morphological characteristics and rDNA internal transcribed spacer sequence analysis identified ANU-301 as Aspergillus terreus. Inoculation of tomato plants with Fusarium oxysporum f. sp. lycopersici (FOL) induced severe wilting symptom; however, co-inoculation with ANU-301 significantly enhanced resistance of tomato plants against FOL. In addition, culture filtrate (CF) of ANU-301 not only showed bacterial growth inhibition activity against Dickeya chrysanthemi (Dc), but also demonstrated protective effect in potato tuber against soft rot disease. Gas chromatography-tandem mass spectrometry analysis of CF of ANU-301 identified 2,4-bis(1-methyl-1-phenylethyl)-phenol (MPP) as the most abundant compound. MPP inhibited growth of Dc, but not of FOL, in a dose-dependent manner, and protected potato tuber from the soft rot disease induced by Dc. In conclusion, Aspergillus terreus ANU-301 could be used and further tested as a potential biological control agent.

• Research in Plant Disease
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• v.8 no.3
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• pp.146-161
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• 2002

Incidence of soilborne diseases, as a major cause of failure of continuous monocropping becomes severe in recent years. For examples, recent epidemics of club root of chinese cabbage, white rot of garlic, bacterial wilt of potato, pepper phytophthora blight, tomato fusarium wilt and CGMMV of watermelon are the diseases that require urgent control measures. Reasons for the severe incidence of soilborne diseases are the simplified cropping system or continuous monocropping associated with allocation of major production areas of certain crop and year-round cultivation system that results in rapid degradation of soil environment. Neglect of breeding for disease resistance relative to giving much emphasis on high yield and good quality, and cultural methods putting first on the use of chemical fertilizers are thought to be the reason. Counter-measures against soilborne disease epidemics would become most effective when the remedies are seeded for individual causes. As long-term strategies, development of rational cropping system which fits local cropping and economic condition, development and supply of cultivars resistant to multiple diseases, and improvement of soil environment by soil conditioning are suggested. In short-term strategies, simple and economical soil-disinfestation technology, and quick and accurate forecasting methods for soilborne diseases are urgent matter far development. for these, extensive supports are required in governmental level for rearing soilborne disease specialists and activation of collaborating researches to solve encountering problems of soilborne diseases.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.40-47
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• 2005

In order to develop a multi-microbial biofungicide against several important plant pathogenic fungi, strains were isolated from the phtophthora blight suppressive red-pepper field soil of Gyeongsangbuk-do, Korea. Strains AY1, AY6, AB1, BB2 and F4, which had strong antagonistic ability against Phytophthota capsici and Fusarium oxysporum, were selected for their involvement with strains of biocontrol fungicide. There were no antagonism among the selected strains and were compatible for making the biofungicide. Their antagonistic mechanisms, except for strain BB2, were an antibiosis by the production of antibiotic, while BB2 produced not only an antibiotic but also cellulase as an antagonistic mechanism against blight causing P. capsici. They were identified as Halobacterium sp. AB1, Xenorhadus sp. AY1, Bacillus sp. AY6, Bacillus sp. BB2, Zymomonas sp. F4 by various cultural, biochemical test and $Biolog^{TM}$ System 4.0. The highest levels of antifungal antibiotic could be produced after 48 hrs of incubation under the optimal medium which were 0.1% galactose, 0.1% $NaNO_2$, 5 mM $Na_2{\cdot}HPO_4$ (pH 5.5). The cultured multi-microbial biofungicide showed strong biocontrol activity against bacterial wilt disease and fusarium wilt disease in cucumber and tomato fields.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.779-789
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• 2016

A total of 33 accessions of pepper (Capsicum spp.), including previously reported and newly discovered sources of resistance to bacterial spot caused by Xanthomonas euvesicatoria, were evaluated for their resistance to bacterial spot. The selected accessions were then grown and their horticultural characteristics were recorded. In a test for hypersensitive resistance (HR) to four races (P1, P3, P7, P8) of the pathogen found in Korea, KC00939 and Chilbok No.2, which carry the Bs2 gene, exhibited a hypersensitive response to all four races, as expected. Chilbok No.3, which carries the Bs3 gene, showed a hypersensitive reaction to race 1 and 7, as expected. KC00939 exhibited a high ASTA color value and tolerance to multiple infections from a viral complex of Cucumber mosaic virus (CMV) and Broad bean wilt virus (BBWV). Thus, this accession represents a promising genetic resource for breeding cultivars with multiple disease resistance and strong red coloration. KC01327, KC01617, KC01015, KC01760, KC01779, KC01137, KC01328, KC01006, KC00127, KC01704, and KC00995 did not exhibit hypersensitivity but showed a high level of general resistance when evaluated by spray inoculation. KC01617, KC01760, KC01779, KC01137, KC01704, and KC01777 are newly identified sources of resistance to bacterial spot. The previously and newly identified sources of resistance to bacterial spot evaluated in this study, including information about their resistance to CMV and BBWV complex in the field, the contents of pungent and sweet taste components, and the color values of dry fruits, will be useful for breeding pepper cultivars with resistance to bacterial spot.

• Journal of Environmental Science International
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• v.21 no.7
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• pp.797-804
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• 2012

A dielectric barrier discharge (DBD) plasma reactor was investigated for the inactivation of Ralstonia Solanacearum which causes bacterial wilt in aquiculture. The DBD plasma reactor of this study was divided into power supply unit, gas supply unit and plasma reactor. The plasma reactor consisted of a quartz dielectric tube, discharge electrode (inner) and ground electrode (outer). The experimental results showed that the optimum 1st voltage, 2nd voltage, air flow rate and pH were for 100 V (1st voltage), 15 kV (2nd voltage), 4 L/min, and pH 3, respectively. At a low 1st voltage, shoulder and tailing off phenomena was observed. The shoulder phenomenon was decreased as the increase of 1st voltage. R. Solanacearum disinfection in the lower air flow rate was showed shoulder and tailing off phenomenon because the active species generated less. Under optimum condition, shoulder and tailing off phenomenon was reduced. When the 2nd voltage was less than 7.5 kV, tailing off phenomenon was observed and this was not vanishes even though the increase of the disinfection time. The inactivation efficiency increased as the increase of air flow rate, however, the efficiency decreased when the air flow rate was above 4 L/min. R. Solanacearum disinfection at pH 3 showed somewhat higher than in pH 11. The pH effect of R. Solanacearum deactivation is less than the impact on other factor.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2011.10a
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• pp.14-14
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• 2011

Polyamines (putrescine, spermidine and spermine) play pivotal roles in plant defense to different abiotic and biotic stresses. In order to understand the function of ginseng spermidine synthase gene, a key gene involved in biosynthesis of polyamines, transgenic plant was generated in Arabidopsis. The transgenic plants exhibited high levels of polyamines compared to the untransformed control plants. We investigated the tolerance capacity of transgenic plants to abiotic stresses such as salinity and copper stress. In addition, transgenic plants also showed increased resistance against one of the important fungal pathogens of ginseng, the wilt causing Fusarium oxysporum and one of important bacteria, bacterial blight causing Pseudomonas syringae. However, an activity of the polyamine catabolic enzyme, diamine oxidase (DAO) was increased significantly in F. oxysporum and P. syringae infected transgenic plant. Polyamine catabolic enzymes which may trigger the hypersensitive response (HR) by producing hydrogen peroxide ($H_2O_2$) seem act as an inducer of PR proteins, peroxidase and phenyl ammonium lyase activity. The transgenic plants also contained higher antioxidant enzyme activities, less MDA and $H_2O_2$ under salt and copper stress than the wild type, implying it suffered from less injury. These results strongly suggest an important role of spermidine as a signaling regulator in stress signaling pathways, leading to build-up of stress tolerance mechanisms.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.203-209
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• 1987

The substances obtained from the leaf, stem and root of tobacco plants inoculated with avirulent and virulent isolates of Pseudomonas solanacearum were at R_f\;0.6$ and R_f\;0.9$ on TLC plate, respectively. Both substances showed antibacterial activities not only on P. solanacearum but also on Erwinia carotovora subsp. carotovora and Escherichia coli in vitro. However, the antibacterial substances were not detectable from the filtrate of the autoclaves tobacco sap medium, in which the avirulent or virulent bacterium was cultured for 3 days. Peroxidase and poly phenoloxidase activities and their isozyme patterns did not differ significantly between plants treated with the virulent and avirulent isolates, or between the susceptible cultivar BY 4 and the resistant cultivar NC 82. However, activities of the two enzymes were increased in leaves of the susceptible cultivar BY 4 treated with either the virulent or the avirulent isolate.