• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.129.2-130
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• 2003

Tomato soil pathogens(Phythopthora spp.) analyed high rates in series culture soil and existed in culture parts. To make a diagnosis of Phythopthora sp. and Its concentration, potato slices were manufactured to a round shape(2.5cm) or retangular form(1x4cm). and then, The potato slices dipped into diagnostic reagents with an antibiotic substance for 2∼4hours. Potato slices treated with a few reagents varied into 15cm depths in innoculated soils for 24hrs. Mycelium of the Phytophthora root rot fungus, Phythopthora capsici, were produced easily on potato slice. We collected many potato slice samples on diseased fields in various area. After storage of 24hrs in 20$^{\circ}C$ incubator, White mycelium of Phythopthora sp. formed on potato slice surface. Dilute concentrations of Phythopthora sp. was detected very low contents(1${\times}$10$^1$sporangia/g). But expressing Phythopthora root rots on potato slice did not developed larger lesions upon storage time in room temperature. These results suggest that the use of potato slice in a series of soil cultural system may still serve as efficient means of diagnosis of Phythopthora root rots in the absence of control measures.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.125-129
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• 2001

Eight vermiculite-based root media prepared with addition of complete fertilizer (2 g/L; N-$P_2$$O_5$-$K_2$O, 10-10-14) for potatoes (Solanum tuberosum L.) and a commercial root medium were evaluated in 2000 to develop the root media suitable for potato plug seedling production. The eight media consisted of various ratios of vermiculite, perlite, peatmoss, and compost. In addition, four rates (0, 1, 2, or 4 g/L) of the complex fertilizer for potato were added to a root medium (70% vermiculite, 10% perlite, 10% peat moss, and 10% compost by volume) to determine the optimum addition rate of the complex fertilizer for plug seedlings. Compost addition to the media increased plant height, the number of leaves per plant, and top and root fresh weight of 15-day old plug seedlings. The seedlings raised in root media containing compost produced significantly higher total tuber yield. Addition of the complex fertilizer to root media enhanced seedling growth and increased the number of tubers per plant and tuber yields. The results suggest that root media containing 50% vermiculite, 0 to 20% peat moss, 10% perlite, 20 to 40% compost, and 2 g/L complex fertilizer for potato appear suitable for potato plug seedling production.

• Korean journal of applied entomology
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• v.16 no.3 s.32
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• pp.145-148
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• 1977

he study was conducted to produce an antiserum of potato virus S for identification and screening of seed-potatoes. Potato virus S was isolated from infected plants and identified by means of indicator plants and electro microscopy. Isolated potato virus S was multiplied in Nicotiana deebneyii and the virus was purified by a modified method that was developed through this study. The purity of potato virus S was 1.18mg/ml. Purified potato virus S was injected into rabbit intravenously once a week for 5 weeks. Antiserum was collected 10 days after the last injection. The produced antiserum was determined to have a titer of, 1/2048 by means of microprecipitin tests.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.224-229
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• 2009

Human lactoferrin is an iron-binding glycoprotein with many biological activities, including the protection against microbial and virus infection and stimulation of the immune system. We introduced a human lactoferrin (hLf) cDNA under the control of 35S promoter into sweet potato by particle bombardment. Transgenic plants were regenerated via somatic embryogenesis. Transgenic plants were produced typical tuberous roots in soil. PCR, Southern and northern analyses confirmed that the hLf cDNA was incorporated into the plant genome and was properly expressed in plants. Western blot analysis showed that the 80 kDa full length hLf protein was produced in transgenic tuberous roots. Overall results indicated that sweet potato would be an excellent host to produce human therapeutic proteins.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.416-424
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• 2014

Sweet potato is grown extensively from tropical to temperate regions and is an important food crop worldwide. In this study, we established detection methods for 17 major sweet potato viruses using single and multiplex RT-PCR assays. To investigate the current incidence of viral diseases, we collected 154 samples of various sweet potato cultivars showing virus-like symptoms from 40 fields in 10 Korean regions, and analyzed them by RT-PCR using specific primers for each of the 17 viruses. Of the 17 possible viruses, we detected eight in our samples. Sweet potato feathery mottle virus (SPFMV) and sweet potato virus C (SPVC) were most commonly detected, infecting approximately 87% and 85% of samples, respectively. Furthermore, Sweet potato symptomless virus 1 (SPSMV-1), Sweet potato virus G (SPVG), Sweet potato leaf curl virus (SPLCV), Sweet potato virus 2 ( SPV2), Sweet potato chlorotic fleck virus (SPCFV), and Sweet potato latent virus (SPLV) were detected in 67%, 58%, 47%, 41%, 31%, and 20% of samples, respectively. This study presents the first documented occurrence of four viruses (SPVC, SPV2, SPCFV, and SPSMV-1) in Korea. Based on the results of our survey, we developed multiplex RT-PCR assays for simple and simultaneous detection of the eight sweet potato viruses we recorded.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.253-259
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• 1999

In this study, three simple methods were established to confirm the transgenic potato plants. The leaf disc was used in the first method. After leaf discs of transgenic and non-transgenic potato were transfered into the liquid MS medium with bialaphos 5mg/l, 25 days, the chlorosis occurred in the non-transgenic leaf discs while it could not find in the transgenic leaf discs, In the second method, shoot tips of potato were transferred into MS medium supplemented with 0.5mg/l bialaphos and 0.6% agar. After 7-10 days, a lot of roots developed from the transgenic shoot tip, but the non-transgenic shoot tip was dead. The third method was using chlorophyll contents. Leaf discs were transferred into the liquid MS medium with bialaphos 0.5 mg/l. After 15 days, the content of chlorophyll A in transgenic plant was at least 2.5 times higher than in non-transgenic plant. In addition, the PAT enzyme activity were detected in the transgenic potato, but not detected in normal potato.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.242-248
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• 2011

Several soil bacteria were found to degrade N-Acylhomoserine lactones (NAHLs), thereby interfering with the bacterial quorum sensing system. In this research, fifteen strains of NAHL degrading rhizobacteria were isolated from potato rhizosphere. Based on phenotypic characteristics and 16S rDNA sequence analyses, the strains were identified as members of genera Bacillus, Streptomyces, Arthrobacter, Pseudomonas and Mesorhizobium. All tested isolates were capable to degrade both synthetic and natural NAHL produced by Pectobacterium carotovorum subsp. carotovorum (Pcc) strain EMPCC. In quorum quenching experiments selected isolates, especially Mesorhizobium sp., were markedly reduced the pathogenicity of Pcc strain EMPCC in potato tubers and totally suppressed tissue maceration on potato tubers. These led to consider the latter as a useful biocontrol agent against Pectobacterium spp.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.177-180
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• 2005

Antioxidant activity of crude extracts from colored sweet potato cultivars by plant parts such as root, stem and leaf was evaluated. The highest TBARS values were obtained from root samples of sweet patato, and followed by stems and leaves, indicating that leaf sample showed the strongest antioxidant activity. Sweet potato cultivars with yellow flesh and leaf part exhibited strong antioxidant activities. Antioxidant activities of leaf and stem extracts were maintained for 21 days and were a little lower than that of BHT. The DPPH radical scavenging activity was the highest in "Sinhwangmi" leaf, and followed by "Jami" root. Chlorogenic acid was detected as the most abundant antioxidant substance among all fractions. These results suggest that the antioxidant activity of sweet potato differs depending on plant part and cultivar.

• The Plant Pathology Journal
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• v.18 no.6
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• pp.338-341
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• 2002

The potato scab is caused by several species of Streptomyces. Among these species, only pathogenic strains were found to produce thaxtomin A characterized by necrotic bioassay and HPLC. In this study, identification of the pathogenic strains of Streptomyces was performed through the polymerase chain reaction (PCR) by using specific pathogenicity primer sets derived from the nec1 gene sequences of Streptomyces scabies. The expected PCR products were obtained approximately 580 bp and confirmed by sequencing. This PCR technique can be used effectively to identify the pathogenic Streptomyces species, that cause scab on potato tubers.

• Korean Journal of Veterinary Research
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• v.53 no.4
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• pp.217-224
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• 2013

Transgenic plants have been tested as an alternative host for the production and delivery of experimental oral vaccines. Here, we developed transgenic potatoes that express the major antigenic sites A and D of the glycoprotein S from transmissible gastroenteritis coronavirus (TGEV-$S_{0.7}$) under three expression vector systems. The DNA integration and mRNA expression level of the TGEV-$S_{0.7}$ gene were confirmed in transgenic plants by PCR and northern blot analysis. Antigen protein expression in transgenic potato was determined by western blot analysis. Enzyme-linked immunosorbent assay results revealed that based on a dilution series of Escherichia coli-derived antigen, the transgenic line P-2 had TGEV-$S_{0.7}$ protein at levels that were 0.015% of total soluble proteins. We then examined the immunogenicity of potato-derived TGEV-$S_{0.7}$ antigen in mice. Compared with the wild-type potato treated group and synthetic antigen treated group, mice treated with the potato-derived antigen showed significantly higher levels of immunoglobulin (Ig) G and IgA responses.