• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.31-31
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• 2022

Rice contains a wealth of genetic diversity, both within Oryza sativa and in related A-genome species. Decades of genetic research into this diversity have identified dozens of major genes contributing to a wide variety of important traits, including disease resistance, abiotic stress tolerance (drought, salinity, submergence, heat, cold etc.), grain quality, flowering date and maturity and plant architecture. Yet despite these opportunities, very few of the major genes and QTLs known have been successfully applied through rice breeding programs to produce sustained changes in farmer's fields. This presentation will briefly examine some of the factors limiting application of major genes in the mainstream breeding programs, and steps that have been taken to alleviate those limitations. As a result of these interventions, dozens of major genes that were previously unavailable to breeders are now being used confidently in the variety development process. Case studies will be discussed of genes critical for blast resistance worldwide, rice yellow mottle virus for Africa, and new validated QTLs for salinity tolerance.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.519-523
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• 2011

''Nokyang', a new high biomass yield and whole crop silage rice (Oriza sativa L.) cultivar, was developed by the rice breeding team of National Institute of Crop Science, RDA, Suwon, Korea, during the period from 1996 to 2006 and released in 2007. It was derived from a cross between Yongmoonbyeo/IR67396-16-3-3-1. This cultivar has about 130 days of growth duration from seeding to heading and is tolerance to lodging with erect pubescent leaves, semidwarf (culm length 78 cm) and thick culm. This cultivar has less tillers per hill and more spikelet numbers per panicle than Dasanbyeo. 'Nokyang' has wide and stay green leaf compared other Tongil-type varieties. This new variety is resistant to grain shattering and to some disease including bacterial leaf blight and stripe virus. This variety has good qualities for whole crop silage with high TDN (Total Digestive Nutrient) yield and low NDF (Neutral Detergent Fiber) and low ADF (Acid Detergent Fiber) and high RFV (Relative Feed Value) compared to common high grain yield varieties. The biomass and TDN yield performance of 'Nokyang' is 1,652 MT/ha, 9.9 MT/ha, individually in local adaptability test for three years. 'Nokyang' is adaptable to central plain area, south-eastern plain area of Korea.

• Research in Plant Disease
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• v.13 no.2
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• pp.104-109
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• 2007

Pink root disease of onion, a known worldwide constraint upon onion production, significantly reduces crop levels in the main Korea cultivation area. In order to examine the effect of flooding on incidence of pink root disease caused by Pyrenochaeta terrestris and on onion growth and on populations of soil fungi, field experiments were conducted during two seasons, 2003/04 and 2004/05 at Onion Research Institute. Populations of soil fungi from fields were assayed on selective media. Flooding treatment was effective in reducing populations of P. terrestris, Pythium spp., and Rhizoctonia sp. in soil; fungal populations in soils flooded for 90 days were reduced to 1/2 to 1/3 of those in non-flooded soils. In nursery bed, protective activities of soils flooded for over 60 days were 93.5 to 99.2% and their pink root incidences were less than 5%, which were 1/11 to 1/18 of that in control. Increased yield of onion bulbs was associated with control of soil borne pathogenic fungi by flooding treatments. As flooding period was prolonged, bulb grade showed the tendency to increase. Soil flooding for over 60 days resulted in effective disease control, facilitated accurate planning of plant population in the field, extension of the growing-season and consequently higher yields of better quality.

• Research in Plant Disease
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• v.29 no.3
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• pp.316-320
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• 2023

Recently, the domestic plant disease control policy for fire blight has been implemented partial control in addition to burial control. In this study, an on-site management survey was conducted targeting orchards that implemented partial disease control from 2019 to 2020 in order to find efficient implementation methods for partial disease control. As a result of an investigation into 22 pear and apple orchards in Cheonan and Chungju, 7 orchards were buried. The upper part of the cut infected plants was burned at 16 orchards and covered with plastic vinyl after lime treatment at 6 orchards. The lower stumps of cut infected plants were burned at 7 orchards and covered with plastic vinyl after lime treatment at 15 orchards. There were two orchards where suckers appeared on the stumps even though covers were applied. There was no infection by Erwinia amylovora in the suckers. The conservation condition of lime treatment was good, but warning signs were absent at 6 orchards. Most orchards treated the stumps and surrounding areas with glyphosate-isopropylamine herbicide. The effect of partial control was judged to be safe.

• Research in Plant Disease
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• v.22 no.1
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• pp.32-37
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• 2016

In this work, major outer capsid protein (P10) encoded by genome segment S10 of Rice black-streaked dwarf virus (RBSDV) was expressed in Escherichia coli. Genomic dsRNA was extracted from RBSDV-miryang isolate infected rice plants. Based on the sequence of S10 (RBSDV-miryang, GenBank JX994211), a pair of S10 specific primers were designed and used to amplify the fragment encoding the N-part of P10. We amplified the partial gene (S10 1-834 nt) of RBSDV P10 (1-278 aa) by RT-PCR. Amplified RBSDV S10 (1-834 nt) was cloned into the expression vector pET32a (+). Recombinant RBSDV S10 (1-834 nt) was expressed in E. coli BL21(DE3) and purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity column. We successfully obtained P10 partial protein of RBSDV and the purified protein was used to immunize rabbits. The resulting polyclonal antiserum specifically recognized RBSDV from infected plant in both Western blotting and enzyme-linked immunosorbent assay. In this study, we provide purified RBSDV P10 (1-278 aa), which would be good material for the serological study of RBSDV-miryang isolates.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.250-250
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• 2017

Studies were conducted to select the optimum sowing date and planting density of sesame in the middle area of Korea. To select the optimum sowing date, sesame seeds sowed from 20 April to 7 July with 15-day intervals. To select the optimum planting density, sesame seeds investigated under four different planting distances ($30{\times}10,\;30{\times}15,\;30{\times}20$, and $30{\times}25cm$)respectively in the experimental field. As seeding date was delayed, days to emergence were shortened flowering and maturing date were delayed. Delayed sowing date resulted in decreased length, capsule setting stem length and number of capsules, and branchs per plant. Number of Capsules was high sowing date on 5 May in the range of 90~95ea/plant in sesame. Also yield of sesame seeds was most high on 5 May in the range of 142kg/10a by sowing date. Sowing date up to 5 May showed no effect on grain yield, but from 5 June to 5 July decreased 27%, 68% and 86%, respectively. For all planting distances, weight of 1,000 grain was not significantly different. However, number of branches and capsules tended to increase. Number of Capsules was high planting distance of $30{\times}20cm$ and $30{\times}25cm$ in the range of 146.7~165.7ea/plant in the Geonbaekkae. Areumkkae also showed the same tendency on planting distance of $30{\times}20cm$ and $30{\times}25cm$ in the range of 122.0~147.5ea/plant, respectively. Yield of Geonbaekkae and Areumkkae seeds was most high 116kg/10a, 117kg/10a, respectively on planting distance $30{\times}20cm$. Decreased in the planting distance of sesame has increased the incidence of disease and lodging. Based on the results, we suggest a planting distance of $30{\times}20cm$ maximal growth and yield of sesame in the middle area of Korea. Considering growth characteristics, sesame yield ability, the optimum sowing date was 5 May and optimum planting pattern was founded to be two rows planting in one ridge and planting densities was $30{\times}20cm$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.41-46
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• 2015

In the present study, different expression of protein from Taekwang was revealed by 2-DE, and expressions of protein on each week after flowering was investigated. After analysis of expression of protein, MALDI-TOF was executed to identify expected protein function. Results revealed that there were three patterns of expression of protein during the maturing. The first pattern was that proteins were gradually expressed as up-regulation from 1 week to 6 week. The second pattern was that proteins were expressed gradually from 1 week to 5 week and then it started down-regulation in 6 week. The last pattern was that proteins were gradually as up-regulation from 1 week to 3 week and then down-regulation until 6 week. This phenomenon suggests that young stage has more protein related to correspondence mechanism against disease and growth and then maturing stage has more expression of protein related to storage protein. In MALDI-TOF analysis, p24 oleosin isoform A protein was identified that relates oleosin which is synthetic product in oil body. This protein spot increased gradually until 5 week and then decreased after 5 week. It explained that the protein is active until maturing stage to protect oil in seed and then its activity has gradually degraded. This result may be expected that a protein, related to growth of a seed has increased until maturing and then a seed fills up with a storage protein.

• Research in Plant Disease
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• v.22 no.3
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• pp.178-183
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• 2016

Soybean yellow mottle mosaic virus (SYMMV) is a new emerging plant virus detected in soybean (Glycine max) in Korea. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for rapid detection of SYMMV has been developed. In this study, we have designed primers (SYMM-F3/B3/FIP/BIP) specific to sequences from the coat protein gene of SYMMV genome. Sensitivity analysis showed that RT-LAMP was 10 to 100 times more sensitive than reverse transcription polymerase chain reaction (RT-PCR). The optimal reaction condition of RT-LAMP was determined at $65^{\circ}C$ for 50 minutes. The result indicates that RT-LAMP assay does not require special equipment and long time for SYMMV detection. Therefore, it can be an alternative detection method of RT-PCR in laboratory.

• Korean Journal of Medicinal Crop Science
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• v.24 no.2
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• pp.136-142
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• 2016

Background: Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replant failure in ginseng fields. Methods and Results: Solarization of infested greenhouse soil was carried out during the summer season after applying green manure (Sudan grass) and Calcium Cyanamide (CC) on the soil. Mycelium and conidia of C. destructans died at $40^{\circ}C$ after 15 h, but they did not die at $35^{\circ}C$ after 15 h. They also died after keeping the soil at $40^{\circ}C$ for 2 h daily for 9 days, and at $45^{\circ}C$ for 8 days, but they did not die at $38^{\circ}C$ for 9 days. Maximum soil temperature was $55.4^{\circ}C$ at 5 cm depth, $48.7^{\circ}C$ at 10 cm, $44.7^{\circ}C$ at 15 cm, $42.5^{\circ}C$ at 20 cm, and $31.9^{\circ}C$ at 30 cm by incorporating green manure into the soil and using solarization. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. However, the addition of CC decreased the root weight due to the increase in EC and $NO_3-N$. Conclusions: Soil disinfection using green manure and solarization in a greenhouse environment was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.

• Korean Journal of Breeding Science
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• v.43 no.4
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• pp.282-287
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• 2011

Bacterial pustule (BP) is a leaf disease of soybean that is most common in Korea. Inoculation of 8ra, pathogen strain, to resistant and susceptible cultivars for finding the BP resistance gene (rxp) was much tried but the sequence of the exact gene is not found. This research performed in order to confirm the rxp gene near molecular marker by using the resistant and susceptible cultivars. Soybean BP resistance gene which related to region of near molecular marker could select the resistant cultivar. For the near molecular marker of rxp, reference genomics data available at sequenced Phytozome was used for designing molecular markers. The rxp was mapped between Satt372 and Satt486 on chromosome 17. According to previous study, rxp released in find mapping 7.2 Mbp to 7.3 Mbp on chromosome 17. In this study, we developed 3 random markers near from 6.6 Mbp to 7.3 Mbp on chromosome 17 identified to increase the genetic resolution of the rxp gene region using resistant and susceptible cultivars. Particularly, Rxp17-700 marker was mostly coincided resistance and susceptible genotype to rxp. This result suggests that Rxp17-700 marker will be more tightly linked to rxp gene.