• The Plant Pathology Journal
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• v.35 no.6
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• pp.698-704
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• 2019

Phytophthora root and stem rot (PRSR) caused by Phytophthora sojae is one of the most destructive diseases of soybean. PRSR recently became an issue as soybean cultivation in paddy fields increased in South Korea. The management of PRSR mainly involves R-gene-mediated resistance, however, little is known about the resistance in Korean cultivars. Major Korean soybean cultivars were investigated for the presence or absence of R-gene-mediated resistance to four P. sojae isolates, two of which were new isolates. Isolate-specific reactions were observed following P. sojae inoculation. Of 21 cultivars, 15-20 cultivars (71.4-95.2%) showed susceptible reaction for each isolate. Ten cultivars were susceptible to all the isolates, and six cultivars were identified to have R-gene-mediated resistance to one or two isolates. The results of this study would provide a framework for the discovery of resistant cultivars, development of new cultivars resistant to P. sojae, and investigation of pathogenic diversity of P. sojae population in South Korea.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.99-103
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• 2016

In perennial ginseng plantations, the effective control of various diseases is one of the most critical factors for increasing yields. Enhancing the resistance to disease through induced systemic resistance (ISR) and anti-microbial activity of beneficial soil bacteria, is currently considered to be a potential promising approach to integrate pathogen management for sustainable agriculture. However, the effective in vitro culture systems for testing ISR in ginseng plants have been rarely reported. In this study, I have successfully developed an in vitro germ-free culture system of Panax ginseng seedling for diverse purposes. With this useful system, we also tested BTH-induced priming effects against Botrytis cinerea and Colletotrichum panacicola. Compared to the drain method for enhancing ISR effects to ginseng seedlings, the direct method of spraying leaves somewhat increased the defense activity to these major fungal pathogens. Consistently, the expression of pathogen related PgPR10 and PgCAT were greatly and rapidly enhanced in the BTH-treated ginseng seedlings by treatment with C. panacicola. Our results revealed that the in vitro culture system can be used for developing eco-friendly and versatile bio-control agents for harmful diseases in ginseng cultivation.

• The Plant Pathology Journal
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• v.32 no.5
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• pp.481-488
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• 2016

Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.101-111
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• 2012

Soybean cyst nematode(SCN) (Heterodera glycines Ichinohe) causes the greatest yield loss to soybean compared to any other pest worldwide. Yield loss due to SCN is estimated 7.6 million megagrams in the USA and nearly 9 million worldwide. SCN causes yield reductions by feeding on plant nutrients, retarding root growth, and inhibiting Bradyrhizpbium japonicum(Kirchner) Buchanan nodulation. The primary methods for controlling SCN include planting resistant cultivars and rotation with nonhost crops. Genetically diverse field populations of SCN combined with the limited germplasm base of commercial soybean for resistance could potentially leads to population shifts over time, and this makes controlling H. glycines more difficult. This paper reviewed the importance of soybean, soybean cyst nematode, researches on resistance to SCN, and prospects. Tremendous effort must still be endeavored for elucidating resistance mechanisms and managing H. glycines in the soybean field.

• Journal of Digital Convergence
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• v.19 no.3
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• pp.115-125
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• 2021

This study aims to investigate the effects of self-service technology (SST) characteristics and consumer characteristics on consumer resistance and satisfaction with SST in restaurants. An online survey was conducted for consumers in their 20s and 50s who used SST at restaurants, and 343 data were used for analysis. As a result, convenience and tech-controllability have a negative effect on consumer resistance with SST, whereas complexity, social risk and relationship orientation have a positive effect. In addition, convenience, entertainment, and tech-controllability have a positive effect on consumer satisfaction with SST, whereas social risk and relationship orientation have a negative effect. This study contributes practically and academically in that it proposes a practical strategy to reduce consumer resistance and increase satisfaction, and identifies the determinants of consumer response to SST. In future studies, an in-depth analysis of consumers' ambivalent responses to SST is required.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.652-661
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• 2021

Xanthomonas citri pv. glycines (Xcg) is a major pathogen of soybean (Glycine max) in South Korea, despite the availability of soybean varieties with some resistance. We conducted a nationwide survey of the incidence and severity of bacterial pustule caused by Xcg. The percentage of infected fields was 7% to 17% between 2015 and 2017. We characterized the diversity of a nationwide collection of 106 Xcg isolates based on avrBs3 banding patterns. The isolates fell into 11 groups, each represented by a type strain; only two of these were similar to isolates collected from 1999 to 2002. The diversity of Xcg strains increased and the dominant strains changed between 1999 and 2017, with three new type strains comprising 44% of the isolates examined in 2012 to 2017. Pathogenicity tests did not show evidence for a shift in the races or aggressiveness of Xcg strains. Korean soybean cultivars, including the widely-grown Daewon cultivar, were susceptible to the 11 new type strains. The cultivar CNS, which carries the rxp resistance gene, was susceptible to most type strains, including two representing 83% of the Korean Xcg strains. In contrast, Williams 82, which also carries rxp, showed resistance to at least five type strains. Collectively, these results suggest that Williams 82 has resistance loci in addition to rxp. The widespread distribution of Xcg, the high virulence of the current endemic strains, and the low resistance of most Korean soybean cultivars collectively favor widespread disease in Korea in years that are favorable to pustule development.

• The Plant Pathology Journal
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• v.39 no.4
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• pp.351-360
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• 2023

Citrus melanose, caused by Diaporthe citri, has been one of the serious diseases, and chemical fungicides were used for protection in many citrus orchards of Jeju Island. Establishing a disinfectant resistance management system and reducing pesticide usage would be important for contributing to safe agricultural production. In this study, monitoring of chemical resistance was performed with 40 representative D. citri isolates from many citrus orchards in Jeju Island. Four different fungicides, kresoxim-methyl, benomyl, fluazinam, and prochloraz manganese, with seven different concentrations were tested in vitro by growing the mycelium of the fungal isolates on the artificial medium potato dextrose agar. Among the 40 fungal isolates, 12 isolates were investigated as resistant to kresoxim-methyl which could not inhibit the mycelium growth to more than 50%. Especially isolate NEL21-2 was also resistant against benomyl, whose hyphae grew well even on the highest chemical concentration. However, any chemical resistance of fungal isolates was found against neither fluazinam nor prochloraz manganese. On the other hand, in vivo bio-testing of some resistant isolates was performed against both kresoxim-methyl and benomyl on young citrus leaves. Typical melanose symptoms developed on the citrus leaves pre-treated with both agrochemicals after inoculation with the resistant isolates. However, no or less symptoms were observed when the susceptible isolates were inoculated. Based on these results, it was suggested that some resistant isolates of D. citri occurred against both systemic fungicides, which may be valuable to build a strategy for protecting citrus disease.

• Information Systems Review
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• v.25 no.1
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• pp.165-187
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• 2023

The continuous increase in life expectancy and high interest in health has brought about significant changes in the use of health information by the public according to the development of information technology represented by the Internet and smartphones. As the medical market expands to the mobile health environment, many health-related apps have been created and distributed, but the acceptance rate is slow as it has become challenging to provide services due to various regulations. In this study, perceived value, perceived risk factors (psychological risk, risk of time-loss, legal risk), and perceived benefits (usefulness, interaction, autonomy) were derived and verified as factors that affect the acceptance resistance of personal health record apps based on the privacy calculation model. In addition, by analyzing the moderating effect of trust in the manufacturer, how the perceived risk and perceived benefit affect the perceived value was verified. A survey was conducted on Korean college students who recognized the personal health record apps but did not use them, and 127 samples were analyzed using structural equations. As a result of hypothesis verification, perceived value has a negative effect on acceptance resistance, perceived risk (risk of time-loss) has a negative effect on perceived value, and perceived benefits (usefulness, interaction, autonomy) were found to have a positive effect on perceived value. Trust in manufacturers has weakened the impact of perceived risks (legal risk) on perceived values. This study is expected to play an important role in maintaining a competitive advantage in the personal health record app market environment by identifying and proposing detailed criteria for reducing the acceptance resistance of personal health record apps.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.22 no.3
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• pp.268-276
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• 2015

Purpose: The purpose of this study was to identify factors which influence the management of MultiDrug -Resistant Organisms (MDROs) by nurses in Intensive Care Units (ICUs). Methods: Data were collected from December 8 to 20, 2013 and participants were 163 ICU nurses working in one general hospital. The Health Belief Model tool and knowledge and management of MDROs infection tools were used in the study. Descriptive statistics, t-test, analysis of variances, Pearson correlation coefficients and multiple regression were used to analyze the data. Results: Knowledge, perceived susceptibility, and perceived benefits had a significant influence on MRSA (Methicillin Resistant Staphylococcus Aureus,) and MDRAB (Multidrug Resistant Acinetobacter Baumannii) infection management when all the other variables were considered. Significant variable which had influence on VRE (Vancomycin Resistant Eenterococci) infection management were perceived susceptibility and perceived benefits. Conclusion: Perceived susceptibility and perceived benefits had significant influence on MDROs infection management. Emphasis needs to be on the perceived susceptibility and perceived benefits of MDROs infection management when providing an educational program for ICU nurses.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.3
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• pp.134-147
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• 2006

A model experiment using circulation water channel was carried out to investigate the dynamic characteristics of bottom trawl net which can be used in sea mount of North Pacific. Hydrodynamic resistance and shape variation according to the flow velocity and angle of hand rope transformation for net were measured, and experimental value was analyzed as the value of full-scale bottom trawl net. The results summarized are as follows; At the $30^{\circ}$ of angle of hand rope to net, hydrodynamic resistance varied from 0.5kgf to 2.68kgf as the flow velocity increased between 0.31m/s and 0.92m/s, and formula of hydrodynamic resistance for the model net was $F_m=3.04\;{\cdot}\;{\upsilon}^{1.53}$. At the fixed angle of hand rope, Net height was low and Net width was high according to the increase of flow velocity, and in addition, vertical opening was low and Net width was high by the increase of angle of hand rope at the fixed flow velocity. At the $30^{\circ}$ of angle of hand rope to net, net opening area was $0.214m^2$ as flow velocity was 0.61m/s, and formula of net opening area for the model net was $S_m=-0.22{\upsilon}+0.35$. At the $30^{\circ}$ of angle of hand rope to net, catch efficiency seemed to be highest as $0.319m^3/s$ of filtering volume at the 0.76m/s(51kt's) of flow velocity. Shape variation of net showed the gradual laminar transform for the variation of flow velocity but there needed some improvements due to the occurrence of shortening at the ahead of wing net.