• 한국작물학회지
• /
• 제52권2호
• /
• pp.220-227
• /
• 2007

Sweetpotato fields in Korea are highly infected with virus and virus like diseases that greatly diminish both yield and quality as indicated by field observations and laboratory tests. In order to solve this problem, there is an urgent need to produce and mass propagate virus-free planting materials for distribution to the farmers. These experiments were conducted, firstly, to determine the most appropriate culture media, nutrient solution, and cutting intervals to maintain growth and vigor of tissue cultured plantleta as mother plants for propagation in insect-proof greenhouse. And as a labor saving method, the production efficiency of plug trays for rapid propagation of stem cuttings as a source of planting materials was likewise evaluated. Results showed that plants grown in medium B supplied with 0.5 and 1.0 strength of MS nutrients had high growth rate, and 20-day cutting interval was the best. 72-plug tray was better than 128-plug. Secondly, it was to develop a technique for the production of first-generation seed roots using hydroponics cultivation system. The yield of virus-free plants propagated in the non-insect proof and open-field cultivation was 2,402 kg/10a, 6% higher than those in the insect-proof cultivation, and the rate of virus re-infection was 18% higher compared to 3.3% with insect-proof cultivation. Lastly, it was to investigate the growth performance of virus free plants in farmers' field. Differences were existed in the yield depending on the variety used, but virus free plants showed an increase of $6{\sim}24%$ over virus infected plants.

• 한국작물학회지
• /
• 제58권1호
• /
• pp.43-49
• /
• 2013

바이러스 무병묘의 만기재배를 통한 우량 씨고구마의 안정적 생산과 적응품종 선발을 위하여, 9 품종의 바이러스 무병묘와 농가묘를 7월 10일 $75{\times}25cm$로 정식하여 흑색비닐로 멀칭재배를 한 다음, 생육특성 및 수량 등을 조사하였다. 1. 정식 30일째의 초기생육은 농가묘보다 무병묘에서 줄기 길이, 줄기 직경, 마디수, 곁가지수 등이 유의하게 증가하였고, 품종 간에도 유의한 차이를 보였으며, '고건미', '신천미', '신황미', '신율미', '연황미' 등에서 초기생육이 양호하였다. 2. 정식 110일째의 지상부 생육에서 줄기 길이, 줄기 직경, 마디수, 분지수 및 생체중 등은 품종간에 유의한 차이를 보였으나, 무병묘와 농가묘간에는 마디수 외에 다른 형질들은 유의한 차이를 보이지 않았다. 3. 만기재배에 따른 무병묘 수량은 품종에 따라 농가묘보다 12-49% 증수되었으며, 무병묘와 농가묘간 평균수량은 각각 1,625 kg/10a과 1,230 kg/10a 으로 무병묘에서 유의하게 증가하였다. 4. 씨고구마로 이용할 수 있는 40 g 이상의 상저비율은 무병묘 65.6%, 농가묘 57.8%로 무병묘에서 유의하게 증가하였으며, 무병묘와 농가묘간 상저수량은 각각 1,067 kg/10a과 710 kg/10a 이었다. 5. 공시된 9품종 중에서 1,300 kg/10a 이상의 상저수량을 보인 '신자미', '신천미', '신율미' 등 3품종의 만기재배 적응성이 높았다.

• 한국작물학회지
• /
• 제60권1호
• /
• pp.54-62
• /
• 2015

고구마 바이러스 무병묘의 지역에 따른 우수성을 입증하기 위하여 바이러스 무병묘와 일반묘를 대상으로 5지역(논산, 보령, 익산, 무안, 함안)에서 5개의 품종(주황미, 신자미, 신황미, 신건미, 그리고 연황미)으로 바이러스 무병묘 실증 시험을 진행하였다. 1. 2010년에 수행한 5개 지역 5개 품종의 일반묘와 무병묘의 비교 시험 결과 품종에 따라 최대 68%(신자미, 익산) 생산량이 증가하였으며, 최소 10.7% 감소(신자미, 함양)하였다. 2. 신자미를 제외한 모든 품종은 모든 지역에서 최대 59%(주황미, 함양) 최소 7%(신자미, 무안)증가하여 무병묘가 일반묘에 비하여 경제성이 높았다. 3. 덩굴길이나 무게는 품종과 지역에 따라 무병묘가 일반묘보다 생육이 나빴으나 생산성과는 무관하였다. 4. 논산에서 생산된 무병묘의 상저괴근수는 무병묘가 일반묘보다 3품종(신자미, 연황미, 신건미)에서 낮았으나, 괴근의 평균중이 높아 총생산량은 높았다. 이는 초기 발근 시점인 20일 이내 평균 기온이 다른 지역보다 높아 발근율이 낮아져 생긴 현상으로 판단된다. 5. 모든 품종에서 품종 특성에 맞게 육색과 피색이 더욱 선명하였으며, 괴근의 모양 등 외관 평가에서 무병묘(7~9)가 일반묘(평균3)보다 우수하였으나 당도와 전분가에는 영향이 없었다.

• Journal of Plant Biotechnology
• /
• 제32권1호
• /
• pp.45-50
• /
• 2005

바이러스에 감염된 감귤나무를 생육상에서 주간 $40^{\circ}C$, 야간 $30^{\circ}C$로 열처리한 후 발생한 신초를 $0.3\~0.7\;\cal{mm}$ 로 잘라내어 기내에서 치상한 탱자 (P. trifoliata) 대목에 접목하는 열처리와 경정접목 (shoot-tip grafting)을 병행한 방법으로 무독묘 생산에 성공하였다. 감글 바이러스 즉, citrus tristeza virus (CTV), satsuma dwarf virus (SDV) and citrus tatter leaf virus (CTLV) 에 대한 무독화율은 각각 $75.7\%,\;100.0,\%\;82.6\%$ 였다. 경정접목 시 접수크기는 $0.3\;\cal{mm}$ 이하 일때 바이러스 무독화율이 높았으나 절목 후 활착율은 저하되었다. 열처리 후 경정배양 (shoot-tip culture)을 하여 1 개월 후에 활착율을 조사한 결과 Yuzu (C. junos)는 $74.6\%$, 그리고 early satsuma mandarin (Iwasagi)은 $13.3\%$를 나타내었다. 그러나 항바이러스제인 rivabirin을 첨가한 후 무독효과를 보기 위하여 후대배양 중에 온주밀감의 특성상 갈변되어 고사함으로서 무독묘를 생산하지 못했다.

• Journal of Microbiology
• /
• 제42권1호
• /
• pp.25-31
• /
• 2004

Sf9 cells have obvious advantages for the conventional production technology of vaccine. They are useful tools for high concentration and large-scale cultures. Sf9 cells were grown to maximal concentration, 8${\times}$l0$\^$6/ cells/$m\ell$ in a 500$m\ell$ spinner flask, with a doubling time at the exponentially growing phase of 24.5 hours, using serum-free media. To explore the ability of Sf9 cells to be infected by the Japanese encephalitis (JE) virus Beijing-l strain, Sf9 cells were infected with the virus. By 4-5 days post-infection, 10-15 % of the Sf9 cells showed cytopathic effect (CPE), from granularity to the formation of syncytia and multinucleated giant cells continuously observed over a period of 35 days. Positive fluorescent reactions were detected in 30-40% of cells infected with the JE virus Beijing-l strain, and the uninfected Sf9 cells were completely negative. Virus particles, propagated in Sf9 and Vero cells, were concentrated by sedimentation on 40% trehalose cushions by ultracentrifugation, and showed identical patterns of viral morphogenesis. Complete virus particles, 40 to 50 nm in diameter, were observed, and JE virus envelope (E) proteins, at 53 kDa, were found in the western blot analysis to the anti-JE virus E protein monoclonal antibody and reacted as a magenta band in the same position to the glycoprotein staining. To evaluate whether the infectious virus was produced in Sf9 cells inoculated with the JE virus Beijing-l stain, Sf9 cells were inoculated with the virus, and sample harvested every 5 days. The titers of the JE virus Beijing-l strain rose from 1.0${\times}$l0$\^$5/ to 1.5${\times}$l0$\^$6/ pfu/$m\ell$. The infected Sf9 cells could be subcultured in serum-free medium, with no change in the plaque sizes formed by the JE virus Beijing-l strain in the plaque assay. It is suggested that the ability of the JE virus Beijing-l strain to infect Sf9 cells in serum-free media will provide a useful insect cell system, where the JE virus replication, cytopathogenicity and vaccine immunogen can be studied.

• 한국작물학회지
• /
• 제57권3호
• /
• pp.254-261
• /
• 2012

고구마의 연작장해를 경감시키기 위하여, 연작지 토양과 심토반전 토양에서 농가묘와 바이러스 무병묘를 $70{\times}25cm$ 간격으로 재배하였다. 연작지 토양의 시비량은 $N-P_2O_5-K_2O$ = 55-63-156$kg\;ha^{-1}$과 우분퇴비 10$ton\;ha^{-1}$으로 표준시비를 하였고, 심토반전 토양은 질소비료와 퇴비만을 50% 증시하였다. 삽식 30, 120일째의 생육과 수량 및 품질특성을 조사한 결과는 다음과 같다. 1. 삽식 30일경부터 농가묘에서는 바이러스 병징이 뚜렷하였으나, 무병묘에서는 나타나지 않았다. 2. 무병묘의 수량성은 농가묘보다 심토반전 토양 15.0%, 연작지 10.5%의 증가를 보였다. 3. 심토반전 토양에서의 수량성은 연작지보다 농가묘 8.8%, 무병묘 3.2%의 증가를 보였으며, 심토반전 토양에서 바이러스 무병묘 재배는 상저비율이 농가묘(60.1%) 대비 80%로 높아져 경제성이 있었다. 4. 무병묘에서 수확한 고구마의 품질은 농가묘보다 피색이 선명하고, 고구마 모양이 좋아져 외관 품질향상에도 유리하였다. 5. 심토반전 토양 및 무병묘에서 수량증가는 30일째 엽수와 120일째 분지수와 정의 상관관계(p=0.05)가 인정되었으며, 이는 고구마 괴근형성에 초기생육이 중요하다는 것을 보여주었다.

• Journal of Plant Biotechnology
• /
• 제30권2호
• /
• pp.155-160
• /
• 2003

Grapevine leafroll-associated virus 3(GLRaV-3) is one of the most severe pathogens for viral diseases found in Korea. This study was conducted to establish the virus-free stock production system for the virus disease control. The effects of thermotherapy, merestem culture and chemotheratpy to eliminate the GLRaV-3 in gratevines were tested. Thermotherapy at 37$\pm$2$^{\circ}C$ for 6∼8 weeks combined with 0.5∼1.0mm size of meristem culture method was the most effective for virus elimination. Thermotherapy alone was not effective. In chemotheratpy, DHT and Amantadine (20, 40mg/L) treatment in medium was more effective than Ribavirin to eliminate the GLRaV-3 in grapevine. However, Ribavirin spraying to potted was not available for virus elimination. Therefore, virus-free stock production system using the thermotherapy combined with shoot apical meristem culture was the most effective in grapevine.

• Genomics & Informatics
• /
• 제18권1호
• /
• pp.2.1-2.11
• /
• 2020

In this paper, we propose a new approach to detecting outliers in a set of segmented genomes of the flu virus, a data set with a heterogeneous set of sequences. The approach has the following computational phases: feature extraction, which is a mapping into feature space, alignment-free distance measure to measure the distance between any two segmented genomes, and a mapping into distance space to analyze a quantum of distance values. The approach is implemented using supervised and unsupervised learning modes. The experiments show robustness in detecting outliers of the segmented genome of the flu virus.

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2015년도 추계학술대회 및 정기총회
• /
• pp.37-37
• /
• 2015

dsRNA was found in malformed cultures of Lentinula edodes strain FMRI0339, one of the three most popular sawdust cultivated commercial strains of shiitake, and was also found in healthy-looking fruiting bodies and actively growing mycelia. Cloning of the partial genome of the dsRNA revealed the presence of the RdRp sequence of a novel L. edodes mycovirus (LeV), and sequence comparison of the cloned amplicon showed an identical sequence to known RdRp genes of LeV found in strain HKA. The meiotic stability of dsRNA was examined by measuring the ratio of the presence of dsRNA among sexual monokaryotic progeny. More than 40% of the monokaryotic progeny still contained the dsRNA, indicating the persistence of dsRNA during sexual reproduction. Comparing the mycelia growth of monokaryotic progeny suggested that, although variations in the growth rate existed among progeny and virus infection was observed in highly actively growing progeny, there appeared to be a tendency toward a lower frequency of virus incidence in actively growing progeny. This study attempted to cure the edible mushroom L. edodes strain FMRI0339 of the L. edodes mycovirus (LeV) in order to obtain an isogenic virus-free fungal strain as well as a virus-infected strain for comparison. Mycelial fragmentation, followed by being spread on a plate with serial dilutions resulted in a virus-free colony. Viral absence was confirmed with gel electrophoresis after dsRNA-specific virus purification, Northern blot analysis, and PCR using reverse transcriptase (RT-PCR). Once cured, all of fungal cultures remained virus-free over the next two years. Interestingly, the viral titer of LeV varied depending on the culture condition. The titer from the plate culture showed at least a 20-fold higher concentration than that grown in the liquid culture. However, the reduced virus titer in the liquid culture was recovered by transferring the mycelia to a plate containing the same medium. In addition, oxygen-depleted culture conditions resulted in a significant decrease of viral concentration, but not to the extent seen in the submerged liquid culture. Although no $discernable phenotypic changes in colony morphology were observed, virus-cured strains showed significantly higher growth rates and mycelial mass than virus-infected strains. We were also explored effects of LeV on fruiting body formation and mushroom yield. The fruiting body formation yield of virus-free L. edodes was larger than virus-infected L. edodes. These results indicate that LeV infection has a deleterious effect on mycelial growth and fruiting body formation. In addition, we have been investigated host-parasite interaction between L. edodes and its mycovirus interaction to study viral mechanism by establishment of proteomics.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2019년도 춘계학술대회
• /
• pp.54-54
• /
• 2019

Apple (Malus domestica) is one of the most economically important fruits in Korea. But virus infection has decreased sustainable production of apple and caused the serious problems such as yield loss and poor fruit quality. Virus or viroid infection including Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple mosaic virus (ApMV) and Apple scar skin viroid (ASSVd) has been also reported in Korea. In many cases, apple is infected with virus and viroid with no specific symptoms, the damage caused by the virus are unaware significantly. In our research, we tried to eliminate viruses in the rootstock for the disease-free seedlings of the apple dwarfing rootstock M.9 and M.26. The method of virus elimination was meristem culture, heat($37^{\circ}C$, 6weeks) treatment and chemistry($Ribavirin^{(R)}$) treatment. The analytical methods commonly used for the detection of virus is Enzyme-linked Immuno-Sorbent Assay(ELlSA) and Reverse Transcription-polymerase Chain Reaction(RT-PCR). RT-PCR method was more 30% sensitive than ELISA method. Efficiency of method eliminate virus appeared meristem method > heat treatment > chemistry treatment. The higher acquisition rate of disease-free seedlings is 30~40% on meristem treatment. In meristem treatment, the apple dwarfing rootstock M.9 gained infection ratio of ACLSV, ASPV and ASGV were 45%, 60% and 50% respectively. In the apple dwarfing rootstock M.26, infection ratio of ACLSV, ASPV and ASGV were 40%, 55%, 55%, respectively. Based on our results, it was found that most effective method of disease-free seedlings apple dwarfing rootstocks was by meristem treatment than heat method and chemistry treatment.