• Korean Journal of Agricultural Science
• /
• v.38 no.4
• /
• pp.613-618
• /
• 2011

To develop clubroot resistant Chinese cabbage inbreds, IT 033820, a clubroot resistant turnip, was cross pollinated with a Chinese cabbage inbred of BP 079. From 2005, conventional breeding and microspore culture method performed using these F1 plants as parental materials. In 2007, conventional breeding method resulted in 21 F3 inbreds. After inoculation of clubroot race 4, one inbred showing 83% resistant was selected and registered as 'onkyo 20036ho' in 2008. From 2005, we scanned hybrid cultivars using micro spore culture and developed many doubled haploid (DH) lines in Chinese cabbage. Using Chinese cultivar of 'oong-baek 2ho' we developed 26 DH inbreds in 2007. After inoculation of clubroot race 4, one DH inbred showing 77% resistant and yellow inner leaf color was selected and registered as 'onkyo 20034'in 2008. We found conventional breeding method was effective using introduced germplasm showing low germination. However, when using hybrid cultivar as starting material, microspore culture method was powerful for developing various inbred in short time.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.3 no.1
• /
• pp.105-108
• /
• 2001

The wild entomopathogenic fungi, Cordyceps militaris, were collected at the Whawang mountain, Korea. The pupae of the silkworm, Bombyx mori, were used as infecting hosts for the production of the silkworm-mili-taris dongchunhacho, silkworm vegetable wasps and plant worms with C. militaris. Three inoculation methods in terms of injection, spray and immersion were tested against the silkworm pupae. The three inocu1ation methods revealed 100% infectivity to the silkworm pupae tested. Of the three inoculation methods, the injection method was highly effective in the reduction of the period required for the endosclerotium and the completion of fruiting body formation. These results indicate that the silkworm pupae are very effective host insects for the production of C. militaris.

• The Plant Pathology Journal
• /
• v.33 no.3
• /
• pp.345-349
• /
• 2017

Tomato chlorosis virus (ToCV), a member of the genus Crinivirus, has caused an epidemic disease in tomato worldwide. ToCV is phloem-limited and transmitted by whiteflies in a semi-persistent manner, but not by mechanical inoculation. Experimental propagation of ToCV has been performed primarily by using whitefly-mediated inoculation. To develop a simple and convenient method for transmission of ToCV, we investigated grafting single-leaflets from tomato plants infected with ToCV to recipient tomato seedlings. Forty-one of 46 tomato seedlings tested were grafted successfully with single-leaflets infected with ToCV. Among them, 36 seedlings (87.8%) were systemically infected with ToCV and developed typical symptoms. Our results demonstrated that single-leaflet grafting could provide a sufficient amount of inoculum for the transmission of ToCV to the grafted seedlings.

• The Plant Pathology Journal
• /
• v.32 no.1
• /
• pp.70-76
• /
• 2016

The infectious full-length cDNA clone of zucchini yellow mosaic virus (ZYMV) isolate PA (pZYMV-PA), which was isolated from pumpkin, was constructed by utilizing viral transcription and processing signals to produce infectious in vivo transcripts. Simple rub-inoculation of plasmid DNAs of pZYMV-PA was successful to cause infection of zucchini plants (Cucurbita pepo L.). We further engineered this infectious cDNA clone of ZYMV as a viral vector for systemic expression of heterologous proteins in cucurbits. We successfully expressed two reporter genes including gfp and bar in zucchini plants by simple rub-inoculation of plasmid DNAs of the ZYMV-based expression constructs. Our method of the ZYMV-based viral vector in association with the simple rub-inoculation provides an easy and rapid approach for introduction and evaluation of heterologous genes in cucurbits.

• The Plant Pathology Journal
• /
• v.21 no.2
• /
• pp.158-163
• /
• 2005

Virus-induced gene silencing (VIGS) is a recently developed gene transcript suppression technique for characterizing the function of plant genes. However, efficient VIGS has only been studied in a few plant species. In order to extend the application of VIGS, we examined whether a VIGS vector based on TRV would produce recognizable phenotypes in soybean. Here, we report that VIGS using the Tobacco rattle virus (TRV) viral vector can be used in several soybean cultivars employing various agro-inoculation methods including leaf infiltration, spray inoculation, and agrodrench. cDNA fragments of the soybean phytoene desaturase(PDS) was inserted into TRV RNA-2 vector. By agrodrench, we successfully silenced the expression of PDS encoding gene in soybean. The silenced phenotype of PDS was invariably obvious 3 weeks after inoculation with the TRV-based vector. Real-time RT-PCR analyses showed that the endogenous level of GmPDS transcripts was dramatically reduced in the silenced leaf tissues. These observations confirm that the silenced phenotype is closely correlated with the pattern of tissue expression. The TRV-based VIGS using agrodrench can be applied to functional genomics in a soybean plants to study genes involved in a wide range of biological processes. To our knowledge, this is the first high frequency VIGS method in soybean plants.

• Journal of the Korean Society of Tobacco Science
• /
• v.30 no.1
• /
• pp.1-7
• /
• 2008

Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tobacco in Korea. No effective single control measure is available at present time. One of the most potential way for controlling the bacterial wilt on tobacco is growing tobacco cultivars resistant to the bacterial wilt. In this study, optimal conditions for screening tobacco cultivars resistant to the bacterial wilt were examined to provide reproducible and efficient methods in growth chamber testing and field experiments for evaluating plant disease resistance. For this, already-known inoculation methods, inoculum densities, and incubation temperature, and plant growth stages at the time of inoculation were compared using tobacco cultivars resistant (Nicotiana tabacum cv, NC95), moderately resistant (N. tabacum cv. SPG70), and susceptible (N. tabacum BY4) to the bacterial disease. It was determined that root-dipping of tobacco seedlings at six true leaf stage into the bacterial suspension with inoculum level of $10^8$ colony-forming units (CFU)/ml for 20 min before transplanting was simple and most efficient in testing for resistance to the bacterial wilt of tobacco caused by R. solanacearum, for which disease incidences and severities were examined at 2 weeks of plant growth after inoculation at $20{\sim}25^{\circ}C$ in a growth chamber. These experimental conditions could discriminate one tobacco cultivar from the others by disease severity better than any other experimental conditions. In field testing, the optimum time for examining the disease occurrence was late June through early July. These results can be applied to establishing a technical manual for the screening of resistant tobacco cultivars against the bacterial wilt caused by R. solanacearum.

• YAKHAK HOEJI
• /
• v.39 no.6
• /
• pp.622-630
• /
• 1995

Inoculation of Friend anemia virus, which was a Kind of retro virus such as HIV, results splenomegaly, anemia, the increase of WBC counts and reverse transcriptase activity in serum. These results were due to the inhibition of the differentiation of erythroid progenitor cell by the FVA at the spleen. Using these as index of antiviral effects, we pursued the establishment of in vivo screening method for the new anti-ADS drugs. Among zidovudine, didanosine and zalcitabine, which were already approved as anti-AIDS drugs, treatment of zidovudine for 18 days in BALB/c mice inoculated with Friend anemia virus resulted the most potent inhibitory effects on the splenomegaly, the increase of WBC counts and reverse transcriptase activity, but did not recovered the anemia due to the tomcity of zidovudhie itself on the bone marrow. The antiviral effects of zidovudine was reduced in case of zidovudine treatment 7 days after Friend anemia virus inoculation. These results suggested that the sooner treatment of zidovudine would be better improved when the virus was inoculated. Human recombinant interferon itself .alpha. did not showed the antiviral activity against Friend anemia virus and did not also affected the antiviral activity of zidovudine. These results suggested that Friend anemia virus would be used as a tool in vivo screening method for the Lobster of reverse transcriptase.

• Journal of Ginseng Research
• /
• v.43 no.1
• /
• pp.77-85
• /
• 2019

Background: Glomus intraradices is a species of arbuscular mycorrhizal fungi that, as an obligate endomycorrhiza, can form mutually beneficial associations with plants. Panax ginseng is a popular traditional Chinese medicine; however, problems associated with ginseng planting, such as pesticide residues, reduce the ginseng quality. Methods: In this experiment, we studied the effect of inoculating G. intraradices on several physiological properties and microbial communities of ginseng. UV-Visible Spectrum method was used to detect physical properties. Denaturing gradient gel electrophoresis method was used to analyze microbial communities. Results: The results indicated that inoculation with G. intraradices can improve the colonization rate of lateral ginseng roots, increase the levels of monomeric and total ginsenosides, and improve root activity as well as polyphenol oxidase and catalase activities. We also studied the bacterial and fungal communities in ginseng rhizospheric soil. In our study, G. intraradices inoculation improved the abundance and Shannon diversity of bacteria, whereas fungi showed a reciprocal effect. Furthermore, we found that G. intraradices inoculation might increase some beneficial bacterial species and decreased pathogenic fungi in rhizospheric soil of ginseng. Conclusion: Our results showed that G. intraradices can benefit ginseng planting which may have some instructive and practical significance for planting ginseng in farmland.

• Journal of Animal Science and Technology
• /
• v.65 no.2
• /
• pp.441-458
• /
• 2023

The poultry industry, which produces excellent sources of protein, suffers enormous economic damage from diseases. To solve this problem, research is being conducted on the early detection of infection according to the behavioral characteristics of poultry. The purpose of this study was to evaluate the potential of a non-movement behavior observation method to detect sick chickens. Forty 1-day-old Ross 308 males were used in the experiments, and an isolator equipped with an Internet Protocol (IP) camera was fabricated for observation. The chickens were inoculated with Salmonella enterica serovar Gallinarum A18-GCVP-014, the causative agent of fowl typhoid (FT), at 14 days of age, which is a vulnerable period for FT infection. The chickens were continuously observed with an IP camera for 2 weeks after inoculation, chickens that did not move for more than 30 minutes were detected and marked according to the algorithm. FT infection was confirmed based on clinical symptoms, analysis of cardiac, spleen and liver lesion scores, pathogen re-isolation, and serological analysis. As a result, clinical symptoms were first observed four days after inoculation, and dead chickens were observed on day six. Eleven days after inoculation, the number of clinical symptoms gradually decreased, indicating a state of recovery. For lesion scores, dead chickens scored 3.57 and live chickens scored 2.38. Pathogens were re-isolated in 37 out of 40 chickens, and hemagglutination test was positive in seven out of 26 chickens. The IP camera applied with the algorithm detected about 83% of the chickens that died in advance through non-movement behavior observation. Therefore, observation of non-movement behavior is one of the ways to detect infected chickens in advance, and it appears to have potential for the development of remote broiler management system.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2000.10a
• /
• pp.54.1-54
• /
• 2000