• Horticultural Science & Technology
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• v.33 no.6
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• pp.883-890
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• 2015

The soilborne fungus Fusarium oxysporum f. sp. lilii (Fol) is a serious threat to all lily cultivars, especially infecting bulbs and flowers. It has become increasingly important to develop varieties resistant against the bulb rot disease. Genetic diversity of cultivars and reliable screening methods are required for this purpose. Here, an efficient in vitro screening system for evaluating resistance to Fol in 38 in vitro-grown lily plants was investigated. Various factors including culture conditions of Fol, inoculum density, appropriate plant materials, inoculation method and duration, and incubation period of plant materials after inoculation were combined to optimize the screening method. As a result, we suggest optimal conditions for an in vitro screening system for the selection of Fol-resistant lily cultivars as follows. Fol was grown on potato dextrose agar (PDA) medium for 6 days at $25^{\circ}C$ in darkness and used as working inoculation. Spore suspensions were prepared (inoculum density: $1.0{\times}10^4$ $spores{\cdot}mL^{-1}$), and then leaf segments $1.5{\times}2.0cm^2$ were inoculated by dipping for 22 hours at $25^{\circ}C$ in dark. Later, leaves were cultured on 0.6% agar plates at $25^{\circ}C$ and 50% humidity with a photoperiod of 16 hours light/8 hours dark (fluence rate of $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) to examine the progress of bulb rot. After 7 days, disease levels were classified into indices 1 (no symptom) to 6 (serious bulb rot). Soil inoculation of Fol carried out with resistant or susceptible lily cultivars that had been selected through in vitro screening confirmed the reproducibility of results. Therefore, the in vitro screening method established in this study is efficient and reliable for selection of lily cultivars resistant against bulb rot disease.

• The Plant Pathology Journal
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• v.19 no.5
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• pp.248-252
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• 2003

This study was carried out to evaluate potential of Shiranuhi cultivar against inoculation of causal pathogen of citrus canker, Xanthomonas axonopodis pv. citri in Jeju Island by comparing degree of susceptibility of fruits and leaves/twigs, and analysis of incidence of canker disease. Progression of symptom, disease incidence, and percent area of lesion were surveyed for evaluation of resistance. In greenhouse condition, symptoms of bacterial citrus canker progressed more rapidly in sweet orange, a moderately susceptible cultivar, than in other four cultivars (satsuma mandarin, 'Kiyomi', 'Shiranuhi' and 'Yuzu'). At 20 days after inoculation, disease severity was the highest in sweet orange (5.0$\pm$0.0), and all tested leaves were distorted or had dropped. On the other hand, 'Yuzu' showed the lowest disease severity (2.6$\pm$0.47), followed by 'Kiyomi' (4.0$\pm$0.0), 'Shiranuhi' (4.0$\pm$0.82), and satsuma mandarin (4.3$\pm$0.47). Percent area of lesion per leaf 30 days after inoculation was the highest in sweet orange (8.31$\pm$1.78), followed by satsuma mandarin (1.51$\pm$1.25), 'Shiranuhi' (1.39$\pm$0.94), and 'Kiyomi' (1.1$\pm$0.9), while the lowest was in 'Yuzu' (0.26$\pm$0.17). Infield condition, percentage of diseased leaf in 'Shiranuhi' was very low, 5.2$\pm$2.9, compared with sweet orange, 71.0$\pm$ 11.5, while that of satsuma mandarin and 'Kiyomi' were 6.9$\pm$7.0 and 4.3$\pm$2.0, respectively. Percentages of diseased leaf was higher (17.4$\pm$7.1) than that of diseased fruit (3.2$\pm$2.5) in severely diseased trees of Shiranuhi cultivar, and the disease was not observed on twig in open field condition. Lesion sizes on leaves and fruits in open field condition were 4.1$\pm$2.2 mm2 and 5.1$\pm$5.6 mm2, respectively, while those in greenhouse condition were 8.7$\pm$5.7 mm2, 10.4$\pm$9.2 mm2 and 5.6$\pm$2.6 mm2 on leaves, fruits and twigs, respectively. The disease was observed in 5.6% out of total 107 farmers Shiranuhi fields under polyethylene film house, and average percentages of diseased tree in 31 fields of Shiranuhi cultivar and adjacent satsuma mandarin fields were 0.02% and 14.8%, respectively. Average percentage of diseased fruit was 1.6% in satsuma mandarin which was not observed in anyone of all the 31 Shiranuhi farmers fields. Therefore, it was concluded that 'Shiranuhi' cultivar is not potential against causal pathogen of citrus canker disease in Jeju Island because the cultivar has similar resistance as satsuma mandarin which occupies over 95% of total 25,000 ha in Jeju Island in polyethylene film houses protected from outside.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.181-188
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• 1992

This study was carried out to evaluate the fate of inoculant Bradyrhizobium japonicum and the inoculation effect on soybean in complex soil environment. To moniter Rhizobium strains from the root, streptomycine and streptomycine and nalidixic acid resistant marker strains were prepared by spontaneous mutagenesis. The characteristics and properties of antibiotic marked strains were not altered by the mutagenesis. The comparison of properties of wild type and antibiotic resistant Bradyrhizobium strains are summarized as follow : 1) The strains of USDA110K-$STR^r$, USDA110N-$STR^r$ and R318-$STR^r$ showed weak tolerance to pH 9.0. The utilization of carbon sources by fast growing group was different from that of slow growing group. The marked strains of R214-$STR^rNAL^r$, USDA110K-$STR^r$ and USDA110N-$STR^r$ was doubtful in utilization of sorbitol and R138-$STR^rNAL^r$ was doubtful in utilization of xylose as a carbon source. 2) By examining the agglutination reaction of serogroups, the strains used were identified as different ones. There were no differences between wild type and marked strains in agglutination titer values. 3) The plasmid size of fast group was slightly greater than that of slow group. However, there was no differences in plasmid size between the wild type and antibiotic resistant strains. This result indicates that the antibiotic resistance was not encoded in plasmid. 4) The recovery of the inoculated strains was up to 12.5 % in soybean cultivated soil and was up to 25 % in soybean uncultivated soil. 5) When the wild type or marked strains were inoculated. there was no significant effect on soybean plant, whereas the inoculation effect was pronounced in soybean uncultivated soil. The inoculation effect seemed to be more pronounced in wild type strains than antibiotic resistant strains. however, the difference was not significant.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.103-107
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• 2004

This study was carried out to investigate the growth of pathogenic germ in fermented pork with Korean traditional seasonings. The samples, outside muscle of pork ham were cut by the shape of cube (7${\times}$12${\times}$2cm) and seasoned with five Korean traditional seasonings such as garlic paste (Tl), pickled Kimchi (T2), pickled Kimchi juice (T3), soybean paste (T4), red pepper paste (T5). The rate of meat to seasonings was same. The seasoned samples were fermented at -1${\pm}$1$^{\circ}C$ for 28 days. Microbial pathogens such as Escherichia coli O157, Listeria monocytogenes, Salmonella enteritidis were not detected in all paste and samples. When 1.5${\times}$l0$^3$ CFU/$\textrm{cm}^2$ of Escherichia coli O157 was inoculated, the numbers were slightly increased to 10$^3$-10$^4$ CFU/$\textrm{cm}^2$ at 3 days and gradually decreased to the level of inoculation at 18 days in all samples. In the inoculation with Listeria monocytogenes (8${\times}$l0$^4$ CFU/$\textrm{cm}^2$), the numbers were below 10$^3$ CFU/$\textrm{cm}^2$ during 28 days in T3 and T4, while they were increased to 10$\^$6/ CFU/$\textrm{cm}^2$ in Tl and T2 at 3 and 13 days respectively, and decreased to 10$^4$ CFU/$\textrm{cm}^2$. In the inoculation with Salmonella enteritidis (3${\times}$l0$^4$ CFU/$\textrm{cm}^2$), the numbers increased to 10$\^$5/ CFU/$\textrm{cm}^2$ at 18 days, but they were rapidly decreased to the level of initial inoculation at 23 days.

• Korean Journal of Agricultural Science
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• v.32 no.1
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• pp.71-80
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• 2005

Phytic acid chelates excellently the metallic ions and the positive ions, especially has high affinity with $Fe^{2+}$ and $Ca^{2+}$. Merits of phytic acid can be taked in easily, edibile and harmless to body, so it was investigated that phytic acid can be substituted for EDTA in this study. 1. The Intensificative effect of chelating agent and disinfective osmotic shock of Vibrio vulnificus The number of initial existent fungi measured $1.7{\times}10^6$. The percentages of the survival fungi against the osmotic shock by distillated water were calculated at 1 minute, 3 minute and 5 minute after inoculation. The percentages of the survival fungi in $Mg^{2+}$ were 92.5%, 91.8% and 79.8% at each time, the average percentage was 88%. Also the sudden extinction was observed around 1 minute after inoculation and the survival fungi were not observed from 3 through 5 minute in spite of repeated experimentation. 2. Influence of Vibrio vulnificus on the survival of the mice. The first mouse started to die in 180 minute after inoculation in case that the inoculating number was $2.3{\times}10^7cfu/ml$. All died within 4.5 hour. The average of survival time was 226 minute. The first mouse started to die in 228 minute after inoculation in case that the inoculating number was $0.8{\times}10^6cfu/ml$. All died within 5 hour. The average of survival time was 300 minute and the survival time was 1.3 times high. The tendencies of death in two cases were similar, but the fatal rate were largely dependent on inoculating number.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.72-77
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• 1989

A study was conducted to obtain acid tolerant and superior Rhizobium meliloti strain for alfalfa on hilly acid soils. With host plant, eight isolates of R, meliloti selected in the vicinity of Milyang were evaluated for their ability to establish symbiotic effectiveness in acidified tube culture medium and vermiculite pot with different urea levels. Among isolates "YA03" was characterized for the ability to manifest to acid tolerance in three different soils of which pH were 5.0, 6.0, and 7.5. The results obtained were summarized as follows: 1. Of eight isolates "YA03" and "YA09" performed nodule in the tube medium of pH5.0, and in the symbiotic effectiveness YA03 was superior to others. 2. Alfalfa growth and $N_2-fixing$ activity by the inoculation of "YA03" isolate were better than others at the level of urea 1.25mM as well as nonurea. 3. Application of urea with inoculation of "YA03" islate to alfalfa was one of the effective factors for symbiotic effectiveness. 4. In infertile soil of pH5.0 inoculation of R. meliloti "YA03" to alfalfa caused the increase of shoot dry matter of 320% as compared to the control, and the total amount of yield was 131% as much yield in moderate fertile soil of pH7.5. Finally R. meliloti "YA03" isolate was selected as an acid tolerant strain.

• Herbal Formula Science
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• v.21 no.1
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• pp.51-70
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• 2013

Objectives : The object of this study was to observe anticancer and related immunomodulatory effects of Insamyangyoung-tang extracts (ISYYTe) on non-small cell lung carcinoma (squamous epithelial carcinoma), NCI-H520, xenograft Balb/c nu-nu nude mice. Methods : Three different dosages of ISYYTe, 50, 100 and 200 mg/kg were orally administered once a day for 42 days from 11 days after tumor cell inoculation. Six groups, which are intact control, tumor bearing control, 5-fluorouracil (FU) 30 mg/kg, ISYYTe 50 mg/kg, ISYYTe 100 mg/kg, ISYYTe 200 mg/kg, each of 8 mice per group were used in the present study. Changes on the body weight, tumor volume and weight, lymphatic organ (spleen and popliteal lymph node), serum interferon (IFN)-${\gamma}$ levels, splenocytes NK cell activity and peritoneal macrophage activities, splenic tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$ and IL-10 contents were observed with tumor mass and lymphatic organ histopathology to detect anticancer and immunomodulatory effects. Results : As results of ISYYTe 50, 100 and 200 mg/kg treatment, decreases in the tumor volumes and weights were detected. At histopathological observations, decreases of tumor cell volumes in tumor masses were dose-dependently decreased mediated by increases of apoptosis among tumor cells by treatment of all three different dosages of ISYYTe. As results of tumor cell inoculation, marked decreases of spleen and popliteal lymph node weights, serum IFN-${\gamma}$, splenic TNF-${\alpha}$, IL-$1{\beta}$ and IL-10 contents and splenocytes were observed with histopathological atrophic changes of spleen and popliteal lymph nodes. Conclusions : Over 50 mg/kg of ISYYTe showed favorable anticancer effects on the NCI-H520 cell xenograft with immunomodulatory effects. Although relatively lower anticancer effects were observed in ISYYTe 200 mg/kg treated mice as compared with 5-FU 30 mg/kg treated mice, there are no meaningful favorable immunomodulatory effects were observed after 5-FU treatment in the present study.

• Korean Journal of Veterinary Research
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• v.51 no.3
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• pp.249-252
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• 2011

Cell culture systems for the protozoan Eimeria are not yet available. The present study was conducted to develop an animal model system by inoculating animals with a live Eimeria vaccine. This study was conducted on 3-day-old chickens (n = 20) pretreated with cyclophosphamide. The chickens were divided into 2 groups: the control group (n = 10) and the inoculated group that received the live Eimeria vaccine (n = 10). During the study period, we compared the clinical signs, changes in body weight, and number of oocysts shed in the feces of the control and inoculated group. This study showed that oocyst shedding was significantly higher in the chickens inoculated with live Eimeria oocysts than in the control chickens. Moreover, body weight gain was lesser in the animals in the inoculated group than in the control animals. Fecal oocyst shedding was observed in the inoculated animals. On the basis of these findings, we suggest that live Eimeria vaccination with cyclophosphamide pretreatment may be used to obtain an effective animal model for studying protozoan infections. This animal study model may eliminate the need for a tedious continuous animal inoculation process every 6 months because the live coccidiosis vaccine contains live oocysts.

• Mycobiology
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• v.36 no.2
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• pp.139-141
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• 2008

Anthracnose symptoms were frequently observed on leaves, petioles, and stems of Chinese mallow grown in Namyangju, Korea, during a disease survey performed in November, 2007. The disease incidence was as high as 30% in the 12 greenhouses investigated. A total of 38 isolates of the Colletotrichum species were obtained from the anthracnose symptoms, and all the isolates were identified as Colletotrichum malvarum based on their morphological and culture characteristics. Three isolates of the fungus caused anthracnose symptoms on leaves and stems following artificial inoculation, which were similar to those observed during the greenhouse survey. In this study, mycological and pathological characteristics of C. malvarum identified as causing anthracnose of Chinese mallow were clarified.

• Parasites, Hosts and Diseases
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• v.38 no.4
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• pp.257-261
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• 2000

This study was focused on the effects of microfilament inhibitor, Cytochalasin D (CD) on the invasiveness of sporozoites of Cryptosporidiun spp. into the host cells. MDCK and AGS cell lines were used as host cells for C. parvum and C. muris, respectively. When MDCK cells were pretreated with CD for 1 hr before inoculation of the sporozoites, C. parvum infection was significantly inhibited when compared to the control cells. These inhibitory effects of CD on the rate of infection were dose-dependent. In addition, C. muris infection was hampered when AGS cell lines were pretreated with CD. However, the capability of invasiveness of the sporozoites into the host cells was not greatly influenced by the pretreatment of sporozoites with CD before infection. These results suggest that microfilaments of host cells, rather than parasites, play an important role for the invasion of Cryptosporidium spp.