• Journal of Life Science
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• v.23 no.11
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• pp.1317-1324
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• 2013

High-molecular weight glutenin subunits (HMW-GS) have been shown to play a crucial role in determining the processing properties of the wheat grain. We have produced marker-free transgenic rice plants containing a wheat Glu-1Bx7 gene encoding the HMG-GS from the Korean wheat cultivar 'Jokyeong' using the Agrobacterium-mediated co-transformation method. The Glu-1Bx7-own promoter was inserted into a binary vector for seed-specific expression of the Glu-1Bx7 gene. Two expression cassettes comprised of separate DNA fragments containing only Glu-1Bx7 and hygromycin phosphotransferase II (HPTII) resistance genes were introduced separately to the Agrobacterium tumefaciens EHA105 strain for co-infection. Each EHA105 strain harboring Glu-1Bx7 or HPTII was infected to rice calli at a 3:1 ratio of Glu-1Bx7 and HPTII, respectively. Then, among 216 hygromycin-resistant $T_0$ plants, we obtained 24 transgenic lines with both Glu-1Bx7 and HPTII genes inserted into the rice genome. We reconfirmed integration of the Glu-1Bx7 gene into the rice genome by Southern blot analysis. Transcripts and proteins of the wheat Glu-1Bx7 were stably expressed in the rice $T_1$ seeds. Finally, the marker-free plants harboring only the Glu-1Bx7 gene were successfully screened at the $T_1$ generation.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.503-519
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• 2014

This study was conducted to investigate ginger growth and its nutrient uptake depending on changes of soil properties as affected by applications of green manure crop and/or charcoal in continuous cropping system. The green manure crops applied were barley and hairy vetch, and charcoal was additionally treated in selected plots as a soil conditioner. Experimental plots were prepared as Plot 1 (control), Plot 2 (barley of 8kg $10a^{-1}$), Plot 3 (hairy vetch of 12kg $10a^{-1}$), Plot 4 (charcoal of 1,000kg $10a^{-1}$ and barley 8kg $10a^{-1}$), and Plot 5 (charcoal of 1,000kg $10a^{-1}$ and hairy vetch of 12kg $10a^{-1}$) with two different soil conditions (high clay content, HCC and low clay content, LCC). When comparing selected chemical properties of soils before and after cultivating ginger plant, soil pH decreased from 6.9~8.1 to 6.8~7.6, and electrical conductivity (EC) also declined from $0.45{\sim}1.25dSm^{-1}$ to $0.30{\sim}0.61dSm^{-1}$. However, the content of soil organic matter (SOM) and total nitrogen (T-N) increased. Thus, the soil chemical properties were improved with the applications of green manures and charcoal. Also, macro- and micro-nutrient contents of ginger plants in the different plots were various between normal and diseased plants grown in soils with HCC and LCC. In particular, the concentration of manganese (Mn) was 3~4 folds higher in the diseased plant than in the normal plants. Ginger growth status and yield was relatively improved with the applications of green manures and charcoal as comparing with control plot. Especially in the Plot 4 with LCC, the ginger plant was not infected by root-rot disease.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.4
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• pp.247-254
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• 2003

A study was carried to compare two varieties of tall fescue(Festuca arundinacea Schr.): Fawn (endophyte infection) and Roa(endophyte-free). The study examined plant height, botanical composition, and dry matter yield of mixed pasture. The cattle grazed on a mixed pasture of tall fescue species and orchardgrass(Dactylis glomerata L.), perennial ryegrass(Lolium perenne L.) and white clover(Trifolium repens L.) during March 22, 1997, to September 21, 1997. The number of grazing animals was 4.3/ paddock(50m x50m) and was adjusted according to the condition of pasture. Dry matter yields determined on ungrazed pasture(7-time harvests) were 1,690 $\pm$407kg and 1,128 $\pm$ 238kg/ha on pastures consisting of Fawn and Roa, respectively. This difference was significant(P<0.01). There were 17.71 $\pm$ 1.27cm and 12.83$\pm$0.90cm in average plant lengths of Fawn and Roa(P<0.01), respectively The botanical composition of tall fescue and orchardgrass in the mixture treatment included in the Fawn variety were shown in 34.2 and 3.8％, comparing Roa with 17.1 and 9.6％, on the 21th of September, 1997, respectively. Tall fescue Roa represented a higher botanical composition than orchardgrass(a main species on Cheju). Crude protein content of Fawn was slightly less than that of Roa. From these results, we may conclude that Roa variety is nutritionally better, but is less adaptible to high temperature climate than Fawn. However, Roa variety is still better than orchardgrass in high temperature conditions.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.70-82
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• 2015

This study was conducted to establish an efficient screening system to identify melon resistant to Fusarium oxysporum f. sp. melonis. F. oyxsporum f. sp. melonis GR was isolated from infected melon plants collected at Goryeong and identified as F. oxysporum f. sp. melonis based on morphological characteristics, molecular analyses, and host-specificity tests on cucurbits including melon, oriental melon, cucumber, and watermelon. In addition, the GR isolate was determined as race 1 based on resistance responses of melon differentials to the fungus. To select optimized medium for mass production of inoculum of F. oxysporum f. sp. melonis GR, six media were tested. The fungus produced the most spores (microconidia) in V8-juice broth. Resistance degrees to the GR isolate of 22 commercial melon cultivars and 6 rootstocks for melon plants were investigated. All tested rootstocks showed no symptoms of Fusarium wilt. Among the tested melon cultivars, only three cultivars were susceptible and the other cultivars displayed moderate to high resistance to the GR isolate. For further study, six melon cultivars (Redqueen, Summercool, Superseji, Asiapapaya, Eolukpapaya, and Asiahwanggeum) showing different degrees of resistance to the fungus were selected. The development of Fusarium wilt on the cultivars was tested according to several conditions such as plant growth stage, root wounding, dipping period of roots in spore suspension, inoculum concentration, and incubation temperature to develop the disease. On the basis of the test results, we suggest that an efficient screening method for melon plants resistant to F. oxysporum f. sp. melonis is to remove soil from roots of seven-day-old melon seedlings, to dip the seedlings without cutting in s pore s uspension of $3{\times}10^5conidia/mL$ for 30 min, to transplant the inoculated seedlings to plastic pots with horticulture nursery media, and then to cultivate the plants in a growth room at 25 to $28^{\circ}C$ for about 3 weeks with 12-hour light per day.

• Journal of fish pathology
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• v.25 no.3
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• pp.257-262
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• 2012

A reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) assay was evaluated to monitor infectious hematopoietic necrosis virus (IHNV) from artificially infected rainbow trout Oncorhynchus mykiss. The cumulative mortalities of fish challenged with IHNV at $10^{6.5}\;TCID_{50}$/fish, $10^{5.5}\;TCID_{50}$/fish and $10^{4.5}\;TCID_{50}$/fish were 40%, 0% and 0%, respectively. Dead fish and survivors at 16 and 28 d post-challenge in each group were employed for IHNV detection by RT-LAMP assay and virus isolation using BF-2 cells. IHNV from $10^{4.3}$ to $10^{6.8}\;TCID_{50}/ml$ was isolated from all the dead fish and also detected in all of the examined dead fish by RT-LAMP assay. In survivors at 16 d, 60% (3/5 fish, $10^{2.8}-10^{5.05}\;TCID_{50}/ml$), 20% (1/5 fish, $10^{1.05}\;TCID_{50}/ml$) and 60% (3/5 fish, $10^{1.05}-10^{4.8}\;TCID_{50}/ml$) were found to be IHNV-positive by virus isolation in fish challenged with IHNV at $10^{6.5}\;TCID_{50}$/fish, $10^{5.5}\;TCID_{50}$/fish and $10^{4.5}\;TCID_{50}$/fish, respectively, while 20% (1/5 fish), 0% (0/5 fish) and 20% (1/5 fish) were IHNV-positive by RT-LAMP assay. No IHNV was detected in the survivors at 28 d and control fish. These results indicate that the RT-LAMP assay is useful for detection of IHNV in diseased fish although it is not enough to monitor virus in IHNV-survivors.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.2
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• pp.36-49
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• 2019

The objectives of this study were to extract "Field Survey Based Infection Tree of Pine Wilt Disease(FSB_ITPWD)" and "Object Classification Based Infection Tree of Pine Wilt Disease(OCB_ITPWD)" from the Research Forest at Kangwon National University, and evaluate the spatial distribution characteristics and occurrence intensity of wood infested by pine wood nematode. It was found that the OCB optimum weights (OCB) were 11 for Scale, 0.1 for Shape, 0.9 for Color, 0.9 for Compactness, and 0.1 for Smoothness. The overall classification accuracy was approximately 94%, and the Kappa coefficient was 0.85, which was very high. OCB_ITPWD area is approximately 2.4ha, which is approximately 0.05% of the total area. When the stand structure, distribution characteristics, and topographic and geographic factors of OCB_ITPWD and those of FSB_ITPWD were compared, age class IV was the most abundant age class in FSB_ITPWD (approximately 55%) and OCB_ITPWD (approximately 44%) - the latter was 11% lower than the former. The diameter at breast heigh (DBH at 1.2m from the ground) results showed that (below 14cm) and (below 28cm) DBH trees were the majority (approximately 93%) in OCB_ITPWD, while medium and (more then 30cm) DBH trees were the majority (approximately 87%) in FSB_ITPWD, indicating different DBH distribution. On the other hand, the elevation distribution rate of OCB_ITPWD was mostly between 401 and 500m (approximately 30%), while that of FSB_ITPWD was mostly between 301 and 400m (approximately 45%). Additionally, the accessibility from the forest road was the highest at "100m or less" for both OCB_ITPWD (24%) and FSB_ITPWD (31%), indicating that more trees were infected when a stand was closer to a forest road with higher accessibility. OCB_ITPWD hotspots were 31 and 32 compartments, and it was highly distributed in areas with a higher age class and a higher DBH class.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.228-235
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• 2019

Apple (Malus pumila) is one of the most economically important fruits in Korea. but virus infection has decreased the sustainable production of apples and caused 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) have been also reported in Korea. In many cases, as apple gets infected with virus and viroid with no specific symptoms, the damage and symptoms caused by the viruses are not detected. In our research, viruses in the rootstock were eliminated for a virus-free apple dwarfing rootstock of M.9 and M.26. The virus elimination methods were apical meristem culture, thermotherapy ($37^{\circ}C$, 6 weeks) and chemotherapy($Ribavirin^{(R)}$). The detection of apple viruses was accomplished by Enzyme-linked Immuno-Sorbent Assay (ELlSA) and reverse transcription-polymerase chain reaction (RT-PCR). RT- PCR method was 10 ~ 30% more sensitive than the ELISA method. The efficiency of virus elimination was enhanced in apical meristem culture method. The acquisition rate of virus-free apple dwarfing rootstocks was 30 ~ 40% higher in apical meristem culture. After the meristem culturing of M.9, the infection ratio of ACLSV, ASPV and ASGV was 45%, 60% and 50%, respectively. In the apple dwarfing rootstock of M.26, the infection ratio of ACLSV, ASPV and ASGV was 40%, 55% and 55%, respectively. Based on this study, the best method for the production of virus-free apple dwarfing rootstocks was the apical meristem culture.

• Research in Plant Disease
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• v.25 no.1
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• pp.8-15
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• 2019

Plum pox virus (PPV) is a significant viral disease in Prunus spp. worldwide. A nationwide survey was started in Prunus spp. orchards, since PPV was first detected from peach in Korea, 2015. During 2016-2017, samples were collected from 30,333 trees in 1,985 orchards of stone fruits in 8 provinces and 4 cities, Korea and tested by RT-PCR using specific PPV primer set. As a result, 21 trees including peach (9 trees), Japanese apricot (4 trees), plum (1 tree), apricot (7 trees) in 10 orchards were infected and controlled by eradication program. Amplicons of the expected size (547 bp) were obtained from total RNA of seven peach trees in 2016, and directly sequenced. BLAST analysis revealed the highest nucleotide (NT) identity (99%) with a PPV D isolates (LC331298, LT600782) in Genbank. The seven isolates from shared nt sequence identities of 98 to 100% with one another. Phylogenetic analysis showed the isolates in peach clustered closely with the PPV-D isolates from Korea, Japan, USA, and Canada. This is, to our knowledge, the first report of the presence of PPV in Prunus spp. orchards in Korea, 2016-2017, we hope that our results and efforts will contribute to effective measures for eradication of PPV.

• Journal of Life Science
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• v.31 no.5
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• pp.475-480
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• 2021

Interest in edible insects such as Protaetia brevitarsis has increased rapidly, and several insect producers use these insects in industrialized mass production. However, mass rearing of insects can cause insect diseases. Sprouted barley is a valuable source of nutrients and has antioxidant, antimicrobial, anti-inflammatory, and anti-cancer effects. This study was conducted to investigate the effect of sprouted barley as a feed additive for producing healthy P. brevitarsis larvae. P. brevitarsis larvae were fed feeds with or without sprouted barley, and their body weight and larval period wewe checked weekly. To confirm the antibacterial effects of sprouted barley, in vitro bioassays were performed by counting Serratia marcescens colonies, and in vivo bioassays were performed by determining the survival rate and body weights of the S. marcescens-infected larvae. Larvae fed different feeds were analyzed for their nutrient compositions (i.e., such as proximate composition, minerals, amino acids, and heavy metals). Larvae fed 5% and 10% sprouted barley had maximum weight increases of 19.2% and 23.1%, respectively. Both treatment groups had significantly shorter larval periods than those of the control group. Sprouted barley markedly inhibited the growth of entomopathogenic S. marcescens. Furthermore, larvae fed sprouted barley exhibited higher Cu, Zn, and K levels. Seventeen amino acids were present in larvae fed sprouted barley, of which, tyrosine and glutamic acid were predominant. No heavy metals were detected in any of the investigated groups. Therefore, sprouted barley may be a suitable feed additive for producing high-quality P. brevitarsis larvae.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.376-383
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• 2022

The current study, which consisted of two independent studies (laboratory and greenhouse), was carried out to project the hypothesis fungi-spray scheduling for leaf mold and gray leaf spot in tomato, as well as to evaluate the effect of temperature and leaf wet duration on the effectiveness of different fungicides against these diseases. In the first experiment, tomato leaves were infected with 1 × 10⁴ conidia·mL^-1 and put in a dew chamber for 0 to 18 hours at 10 to 25℃ (Fulvia fulva) and 10 to 30℃ (Stemphylium lycopersici). In farm study, tomato plants were treated for 240 hours with diluted (1,000 times) 30% trimidazole, 50% polyoxin B, and 40% iminoctadine tris (Belkut) for protection of leaf mold, and 10% etridiazole + 55% thiophanate-methyl (Gajiran), and 15% tribasic copper sulfate (Sebinna) for protection of gray leaf spot. In laboratory test, leaf condensation on the leaves of tomato plants were emerged after 9 hrs. of incubation. In conclusion, the incidence degree of leaf mold and gray leaf spot disease on tomato plants shows that it is very closely related to formation of leaf condensation, therefore the incidence of leaf mold was greater at 20 and 15℃, while 25 and 20℃ enhanced the incidence of gray leaf spot. The incidence of leaf mold and gray leaf spot developed 20 days after inoculation, and the latency period was estimated to be 14-15 days. Trihumin fungicide had the maximum effectiveness up to 168 hours of fungicides at 12 hours of wet duration in leaf mold, whereas Gajiran fungicide had the highest control (93%) against gray leaf spot up to 144 hours. All the chemicals showed an around 30-50% decrease in effectiveness after 240 hours of treatment. The model predictions in present study could be help in timely, effective and ecofriendly management of leaf mold disease in tomato.