• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.110-110
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• 2017

Stomata are the main gateways for water and air transport between leaves and the environment. Inward-rectifying potassium channels regulate photo-induced stomatal opening. Rice contains three inward rectifying shaker-like potassium channel proteins, OsKAT1, OsKAT2 and OsKAT3. Among these, only OsKAT2 is specifically expressed in guard cells. Here, we investigated the functions of OsKAT2 in stomatal regulation using three dominant negative mutant proteins, OsKAT2(T235R), OsKAT2(T285A) and OsKAT2(T285D), which are altered in amino acids in the channel pore and at a phosphorylation site. Yeast complementation and patch clamp assays showed that all three mutant proteins lost channel activity. However, among plants overexpressing these mutant proteins, only plants overexpressing OsKAT2(T235R) showed significantly less water loss than the control. Moreover, overexpression of this mutant protein led to delayed photo-induced stomatal opening and increased drought tolerance. Our results indicate that OsKAT2 is an inward-rectifying shaker-like potassium channel that mainly functions in stomatal opening. Interestingly, overexpression of OsKAT2(T235R) did not cause serious defects in growth or yield in rice, suggesting that OsKAT2 is a potential target for engineering plants with improved drought tolerance without yield penalty.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.92-96
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• 2003

The study was conducted to determine the cultural conditions and the effect of inert fillers for melanization and sporulation abilities of sodium alginate pellets, and the weeding efficacy of the formula in the field. Melanin production of E. nematosporus was affected by striking frequency. Percentage of melanized beads was increased to 80.6% at higher rpm up to 180. The melanized pellets produced more conidia with abundant mucilage than unmelanized pellets. Shaker culture of Epicoccosorus nematosporus with sodium alginate yielded a total of 55 mg per 100 pellets. Percentage of melanized pellets was highest with 81.0% and 83.3% of melanization, when wheat bran and rice polish were amended and produced the conidia with 65.4 and 68.4 mg per 100 pellets, respectively. When 1 L of conidial suspension of 6.0$\times$$10^5$ conidia per ml was applied on 30-day-old plants in a plot, 74.5% of the plants were killed within 20 days, whereas, its melanized sodium alginate pellets killed 57.8% of the plants in the same period. The number of tuber formation of Eleocharis kuroguwai in the untreated control plots was 128.5 per plot, but those of the plots treated with conidial suspension and melanized pellets were 22.1 and 39.7, respectively, at the end of the season. Results of this study showed that melanization of mycelia-mixed sodium alginate are an important sporulation factor in E. namatosporus as a mycoherbicide.

• Korean Journal of Medicinal Crop Science
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• v.25 no.3
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• pp.160-164
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• 2017

Background: This study were performed to determine the effect of root pruning of Zizyphus jujuba var. inermis (Bunge) Rehder. Root cutting inhibit vegetative growth and promote reproductive growth as temporarily reducing growth, net assimilation, water potential of leaf and cytokinin level. Methods and Results: The root pruning was treated of the root cutting widths 50, and 80 ㎝ and the root cutting depths 10, and 20 cm. The amount of root pruning and the number of suckers were the highest in the root-pruning treatment at a width of 50 cm and a depth of 20 cm. The blooming time was from June 18 to 20, and no difference was observed in the blooming time among the root-pruning treatments. The number of flowers was rather higher in the root-pruning treatment at a width of 50 cm and a depth of 20 cm and at a width of 80 cm and a depth of 20 cm. The percentage of fruit setting was higher in the plants whose roots were pruned at a depth of 20 cm than in the untreated plants. The fruit size, fruit weight, and sugar content showed no difference among the root-pruning treatments. Conclusions: The results showed that percentage of fruit setting increased with root pruning, while no difference was observed in the growth and fruit quality of plants.

• Journal of Radiation Protection and Research
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• v.44 no.1
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• pp.8-14
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• 2019

Background: Management of an agricultural food product system following a nuclear accident is indispensable for reducing radiation exposure due to ingestion of contaminated food. The present study analyzes the effect of agricultural countermeasures on ingestion dose following a nuclear accident. Materials and Methods: Agricultural countermeasures suitable for domestic farming environments were selected by referring to the countermeasures applied after the Fukushima accident in Japan. The avertable ingestion doses that could be obtained by implementing the selected countermeasures were calculated using the Korean Agricultural Countermeasure Analysis Program (K-ACAP) to investigate the efficiency of each countermeasure. Results and Discussion: Of the selected countermeasures, the management of crops was effective when radionuclide deposition occurred during the growing season of plants. Treatment by soil additive and topsoil removal was effective when deposition occurred during the nongrowing season of plants. The disposal of milk was not effective owing to the small contribution of milk to the overall ingestion dose. Clean feeding of livestock was effective when deposition occurred during the growing season of fodder plants such as pasture and rice-straw. Finally, the effect of food restriction increased with the soil deposition density of radionuclide. The practical effect of countermeasures was very small when the avertable ingestion dose was absolutely low. Conclusion: The agricultural countermeasures selected to reduce the radionuclide ingestion dose after a nuclear accident must be made appropriate by considering the accident situation, such as the soil deposition density of the radionuclide and the deposition date in relation to farming cycles.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.55-55
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• 2022

Purple com Saekso 1 was developed by Maize Research Institute (Hongcheon, Gangwon, Korea) and registered in 2011. Saekso 1 is a anthocyanin-rich hybrid variety that is yellow grain, purple husk and cob. Purple husk and cob of Saekso 1 is as a resource for the bioactive material by health food. In order to investigate optimum sowing date and planting density of Saekso 1. Agronomic characteristics were compared by sowing times April 25, May 15 and June 5. Husk dry weight were 68,72 and 70kg·10a-1, respectively. Cob dry weight were 90, 92 and 92kg·10a-1, respectively. Content of cyanidin-3-glucoside in husk were 0.56, 0.62 and 0.56% and in cob were 0.19, 0.14 and 0.17%. Therefore, the sowing time to increase husk and cob weight and content of cyanidin-3-glucoside is appropriate for planting in mid-May. The number of plants in planting density trial was 9,400, 7,000, 5,700 and 4,700 plants in 10a area. Plant height at each trial were 249, 250, 246 and 248cm, respectively. Husk dry weight were 76, 67 and 63 and 60kg·10a-1, respectively. Cob dry weight were 112, 92, 87 and 81kg·10a-1, respectively. Content of cyanidin-3-glucoside in husk were 0.70, 0.71, 0.71 and 0.75% and in cob were 0.21, 0.28, 0.26 and 0.20%. Therefore, appropriate sowing time was in mid-May and planting density was 5,700~7,000 plants·10a-1 in order to increase the yield and content of cyanidin-3-glucoside of purple com in South Korea.

• The Korean Journal of Pesticide Science
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• v.6 no.1
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• pp.9-15
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• 2002

The insecticide constituents of several Celastraceae family plants including Celastrus angulatus, Celastrus orbiculatus, Celastrus flagellaris, Euonymus verrucosides, Euonymus forunei and Euonymus phellomana were studied by bioassay-guided fractionation. All structures of sesquiterpene polyol esters and alkaloids have been elucidated by UV, IR, MS, NMR and x-ray diffraction evidences. These compounds exhibited insecticidal, antifeedant and narcotic activities against Mythimna separata.

• Korean Journal of Plant Resources
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• v.3 no.1
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• pp.1-30
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• 1990

The traditional plant imprownent methods consisted of pure line selection, cross breeding, heterosis breeding, polyploid breeding, mutati-onbreeding, ect.Biotechmoiogy is divided into gene spliclng , monocle-nal antibodies , protein engineering , agricultural research, and microbiological engineering. Of these , high plants deal with agricultural research, and the importent part of which is tissue culture and celLculture , Tissue .culture and cell culture are again divided into embryoculture, test tube fertilization, anther and pollen culture, somatichybridization , transformation, recombination, recombinant DNA moleculehybrid plasmid, ect For these haploid production, protoplast culture,protoplast fusion, selection and propagation, ect. , the technical sett-lement is needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.254-258
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• 1998

Distribution and occurrence of weedy rice in Kyonggi region were surveyed in 1996. Weedy rice was observed in 1368 fields (54.9%) of total 2490 fields. Almost two thirds of paddy fields in northern mountainous region were contaminated by weedy rice and more severe contamination, three forths of paddy fields, was observed in suburban regions. In those regions, occurrence of weedy rice was greater than those in north-eastern inland and south-western plain regions. The occurrence of weedy rice was higher in water seeding cultivation (66.7%) than other cultivation methods. The number of weedy rice per 10a was 756.7 plants in direct seeding on dry paddy and 379.4 plants in water seeding. The occurrence of weedy rice was higher in fields planted by farmer's seeds than that of paddy fields cultivated by certified seeds, and the longer the farmer's seeds being used, the more weedy rice occurred in paddy field.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.54-55
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• 2002

Soaked black rot symptom was observed on the stem of Angelica acutiloba from July to August 2000 at Kumsan, Chungnam in Korea. This disease usually occurred under humid and high temperature conditions. The lesions on the stem appeared as soft rot with brown elliptical spots, which developed into large black spots at a later stage. When the bacterial isolates from the diseased plants were inoculated onto healthy plants by artificial needle prick method, symptoms similar to that observed in the fields developed. According to the cultural characteristics and pathogenicity of the isolates on the host plant the causal bacterium was identified as Xanthomonas campestris. This study proposed that the disease be named "bacterial black stem rot of A. acutiloba"loba".

• The Plant Pathology Journal
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• v.18 no.2
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• pp.106-108
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• 2002

Severe spotted lesions were observed on tulip plants grown in Asan, Yongin, and Icheon areas in Korea during a disease survey in 2000 and 2001. Diseased plants with severe symptoms were blighted and rotted at the late stage of disease development. A total of 15 isolates was obtained from the infected plant parts of tulip. All the isolates were identified as Botrytis tulipae based on their morphological and cultural characteristics. Three isolates of B. tulipae were tested for their pathogenicity to tulip by artificial inoculation. Spotted lesions similar to those observed in the fields were induced on tulip leaves. This is the first report of tulip fore disease caused by B. tulipae in Korea.