• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.289-289
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• 2022

Waterlogging tolerance of corn is one of the important factor for cultivate in paddy soil condition to increase cultivation area and self-sufficiency of corn in Korea. In order to develop elite waterlogging tolerance corn, the new corn lines bred by crossing wild corn, Teosinte, and cultivated corn inbred lines. Five accessions among the 2 species, Zea mays sub spp. mexicana and Zea mays spp. parviglumis, of 81 Teosinte were selected through the waterlogging treatment. The waterlogging treatments were implemented for 7 days at the seedling(V3) stage. The inbred lines were developed by crossing 5 teosinte accessions and cultivated corn lines and they were estimated waterlogging tolerance. It was screened and analyzed the metabolites extracted from roots of 19KT-32(KS141 × teosinte) that was treated waterlogging. We selected 8 of 180 metabolites like as γ-aminobutyric acid(GABA), putrescine, citrulline, Gly, and Ala that expression was remarkably changed over 2.5-times, 7 metabolites increased and 1 metabolite decreased in waterlogging, respectively. Glutamate decarboxylase(GAD) catalyzing GABA accumulation gene have 10 haplotypes, and exon1 was highly conserved, but identified to 135 SNPs after the first intron. Among the 135 SNPs, the number of transversion mutations (52) surpassed the number of transition mutations (38). Most of metabolites were related to abiotic stress in plant that it regulated to pH, osmotic pressure K⁺/Ca⁺⁺ and ATPase activity. We are analyzing the association using these results for increase breeding efficiency.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.269-273
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• 2006

Multiple linear regression analysis was conducted to interpretate the relationship between sesame grain yield and its components under early sowing cropping condition. The t test showed that stem length, number of capsules per plant, 1000 seeds weight and seed weight per plant gave significant contribution to sesame grain yield, therefore those variables were assumed to mostly influenced components to grain yield of sesame. In the stepwise regression analysis, the predicted equation for sesame grain yield per square meter (Y) was Y = -7.900 + 0.150X1 + 0.461X5 + 15.553X6 + 8.543X7. Meanwhile, F value showed that stem length, number of capsules per plant and seed weight per plant gave significant contribution to sesame grain yield, while 1000 seeds weight did not significantly show. Based on the results, it is reasonable to assume that high yield. potential of sesame under early sowing cropping condition would be obtained by selecting breeding lines with long stem length, number of capsules per plant, and seed weight per plant, which was different result at the late sowing cropping condition in which days to flowering and maturity were assumed to be more affected factors to the sesame grain yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.1
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• pp.42-47
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• 2002

The major free sugars of buckwheat plants were fructose, glucose, and maltose but their contents and compositions were influenced by the different wavelength of light. Free sugar contents of Clfa 39 (Fagopyrum tataricum) were higher than those of Yangjul-maemil (Fagopyrum esculentum) regardless of the light sources. As treated with red and blue light, the free sugar contents in the leaves of buckwheat plants were slightly increased, but their contents in the stems and flowers were lower than those of natural light condition. Under the natural light condition, maltose was detected in every tissues of buckwheat plants, but as treated with blue and red light, it was not detected in the flowers of buckwheat plants. Citric, malic and acetic acid were detected as major organic acids in buckwheat plants. Red and blue lights decreased the total organic acid contents in buckwheat plants as compared with natural light condition. It was considered that blue light are less active than red light for the accumulation of organic acids. Tataric acid was detected only in the leaves of buckwheat plants, however, as treated with red and blue light, it was not detected in the leaves of Clfa 39. Flowers of Yangjul-maemil contained a considerable amount of rutin and quercitrin. Only small amount of quercitrin was detected in leaves, but it was not detected in stems. On the other hand, Clfa 39 leaves contained a considerable amount of rutin, quercetin and small amount of quercitrin, but quercitrin and quercetin were detected only in the stems of Clfa 39. Red and blue lights significantly decreased the contents of rutin, quercitrin, and quercetin in buckwheat plants as comparing with natural light condition. Rutin content in the flowers of Clfa 39 was increased under the red and blue light conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.98-104
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• 2010

Excess nitrogen (N) uptake of rice, which could cause much lodging, disease and reduction of rice quality, could be occurred at the paddy field with previous upland condition at which much soil N could be mineralized by soil-drying effect. N fertilizers of 0, 3, and 6 kg N $10a^{-1}$ were applied to early-maturity rice, cultivar Joanbyeo at the paddy field of first and second year after upland condition, and rice growth and nitrogen uptake were investigated to know the increase of rice N uptake at the paddy field with previous upland condition for one-year. Total dry matter (DM) and N uptake of rice at the paddy field with previous upland condition increased more than continuous paddy field. Total DM and N uptake of rice at the paddy field with previous upland condition increased linearly to N fertilizer 6 kg $10a^{-1}$ at the paddy field owing to vigorous growth compared to continuous paddy field. Rice N uptake was higher at the paddy field of the first year than the second year after upland condition in considering N uptake at the plot of no N fertilizer. Vigorous growth at the paddy field with previous upland condition resulted in higher rice yield which was related with high panicle and spikelet, but much N fertilizer as much as 6 kg $10a^{-1}$ at the paddy field with previous upland condition resulted in higher lodging and protein content of brown and milled rice. Particularly, protein content of brown and milled rice increased more when the same N fertilizer was applied two times splitly at transplanting and panicle initiation stage than when N fertilizer was applied one time at transplanting as basal N. N application with under 3 kg $10a^{-1}$ as only basal N was recommended at the paddy field with previous upland condition to obtain high quality rice without lodging.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.599-607
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• 2006

The experiments were carried out to develop simulation model for estimating the yield of soybean in upland and paddy field condition. Field experiments were done at National Institute of Crop Science in 2005. The evaluated soybean cultivars were Taekwangkong, Daewonkong, and Hwangkeumkong. Soybean seeds were planted by hill seeding with 3-4 seeds and row and hill spacing were $60{\times}10cm$ in upland and $60{\times}15cm$ in paddy field. Seeds were sown on row (without making ridge) and on the top of ridge in upland and paddy field, respectively. Field parameters were measured yield components ($plants/m^{2}$, pod no./plant, and 100-seed weight, seed yield and growth characteristics (stem length, leaf area at each stage, and dry weight of shoot) and after measuring they were compared the relationships with seed yield and yield components and seed yield and growth characteristics. Seed yield of soybean was affected by cultivars and planting density. Seed yield was higher in upland than paddy field due to the higher planting density in upland field. The upland soybeans generally had lower 100-seed weight than that of paddy field. Seed yield of soybean in a paddy field was greatest in Taekwangkong and followed by Daewonkong and Hwangkeumkong. The harvest index of taekwangkong and Hwanggumkong was higher in upland than paddy field, however, it was higher in paddy field than upland in Daewonkong. Seed yield was greatest in Daewonkong in both experimental fields. The greatest stem length was observed in taekwangkong and Hwanggumkong (R6) in late growth stage in paddy field. Dry weight of shoot and pod, pod number, stem length, and stem diameter were higher grown in paddy field than grown in upland. Crop growth rate (CGR) of cultivars was higher in paddy field after 8 WAS(weeks after sowing) and it was greatest at 13 WAS in Daewonkong among the cultivars. In upland field, CGR was greatest in Taekwangkong and then followed by Daewonkong and Hwanggumkong during 12 and 15 WAS. There was no significant relationships between 100-seed weight and seed yield in both experimental fields. A significant positive relationship was observed between seed number and seed yield. The correlation coefficients between leaf area and shoot dry weight were about 0.8 during the whole growth stage except 5 WAS and 4-5 WAS in paddy field and upland, respectively. This experiment was done just one year and drained paddy field condition was not satisfied drained condition successfully at 7th leaf age of soybean by the heavy rain, so we suggest that the excessive soil water reduced seed yield in paddy field and the weather condition should be considered for utilizing of these results.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.1
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• pp.79-84
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• 1991

The rice plants (Oryza sativa L.) established from the shattered grains by combine harvesting at the previous year showed great variations of yield and yield components from site to site at the abandoned rice crop field. The cultural condition was very similar to direct seeding under no-tillage system but no cultural practices such as application of fertilizer, weed control, irrigation and drainage had been carried out. The highest yield of 188kg/10a was observed at one of the quadrats randomly located on the field, which showed the possibility of exploitation of no-tillage system. The interrelationship between crop growth and coverage of weed species was measured by calculating the correlation coefficients. The investigations of how to establish sufficient number of seedlings per unit area, plant succession on the abandoned crop field, crop mixture with legume crops, and breeding appropriate plant type of rice for the enhancement of competitive ability would be required for the success of no-tillage system.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.165-165
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• 2017

Abiotic stress is one of the major serious limiting factors in rice (Oryza sativa) and caused rice production losses. It is important to precisely screen valuable genetic resources for improving stress tolerance and understanding tolerance mechanism to abiotic stresses. Because there are differences of experiment designs for screening of tolerant plant in several studies related to abiotic stress, this study has performed to provide the rapid and efficiency screening method for selection of tolerance rice to drought and salinity stresses. Two week-old rice seedlings that reached about three leaf stage were treated with drought and salinity stresses and examined tolerant levels with tolerant and susceptible control varieties, and transgenic plants. To determine the optimum concentration for the selection of drought and salinity condition, tolerant, susceptible and wild-type plants were grown under three soil moisture contents (5, 10 and 20% water contents) and three NaCl concentrations (100, 200 and 250 mM) for 10 days at seedling stage. 200 mM NaCl concentration and 5% moisture content soil were determined as the optimum conditions, respectively. The described methodologies in this study are simple and efficiency and might help the selection of drought and salinity tolerance plants at the 3,4-leaf-seedling stage.

• Journal of Biosystems Engineering
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• v.18 no.4
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• pp.371-381
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• 1993

Threshing operation is performed by impact, compression and friction forces inside the thresher. These values should be appropriate to the crop condition to enhance the threshing and separating efficiency and to decrease the grain damage. To analyze the threshing process inside the rasp-bar type thresher, impact, friction and compression forces were measured using transducers with strain gage circuits. To measure the impact forces and friction forces between the rasp-bar and crop, full bridge strain gage circuit was built on the rasp-bar holder. To measure the compression forces and circumferential friction forces between the concave and crop, two sets of full bridge strain gage circuits were built on the T-type concave transducer. Threshing work of wheat crop with 12% of moisture content was performed at 3 levels of compression ratio and with 3 replications. Each transducer could not measure the exact forces continuously because the transducer oscillates with the forces. However they could measure maximum forces and force distribution according to the time. Average friction coefficients between crop and concave was 0.61 not showing any significant difference according to the compression ratio. Average acceleration of the crop in the cylinder appeared from $70.6m/s^2$ to $140.8m/s^2$ according to the compression ratio. The velocity of the crop at the exit of the cylinder appeared from 10.7m/s to 15.0m/s according to the compression ratio.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2011.11a
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• pp.16-18
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• 2011

Evaluation of climate change on the rice productivity was conducted using crop growth simulation model, where Odae, Hwaseong, Ilpum were used as a representative cultivar of early, medium, and medium-late rice maturity type, respectively, and climate change scenario 'A1B' was applied to weather data for future climate change at 57sites. When cropping season was fixed, rice yield decreased by 4~35% as climate change which was caused by poor filled grain ratio with high temperature and low irradiation during grain-filling. When cropping season was changed, rice yield decreased by only 0~5% as climate change which was caused poor filled grain ratio with low irradiation during grain-filling period. However, this irradiation decline was less than when cropping season was fixed. Therefore, we need to develop rice cultivars resistant to low irradiation which can maintain high filled grain ratio under poor irradiation condition, and late maturity rice cultivars whose growing period is longer than the present medium-late maturity type.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.229-229
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• 2022

Rapeseed is a crop that is waterlogging sensitive, and it is necessary to breed waterlogging tolerance varieties. Our study presents the comparative transcriptome changes in two rapeseed lines, i.e., waterlogging-tolerant (tJ8634-B-30,) and - sensitive ('EMS26') lines under control and waterlogging stress treatments at the flowering stage. RNA-sequencing analysis revealed 13,279 differentially expressed genes (DEGs) for 'J8634-B-30' and 8,682 DEGs for 'EMS26' under waterlogging stress condition compared to control. Among DEGs of 'J8634-B-30', 6,818 were up-regulated and 6,461 were down-regulated. On the other hand, among the DEGs of 'EMS26', the number of down-regulated genes (5,240) were higher than that of up-regulated genes (3,442). Gene ontology enrichment analysis showed that DEGs related to glucan metabolic, cell wall, and oxidoreductase activity were significantly changed in 'J8634-B-30'. Kyoto Encyclopedia of Genes and Genomes (KEGG)-based analysis in 'J8634-B-30' identified up-regulated DEGs being involved in MAPK signaling pathways. In addition, the DEGs belonging to mechanisms responding to waterlogging stress, i.e., plant hormones, carbon metabolism, Reactive oxygen species (ROS), Nitric oxide (NO) etc. were compared in rapeseed lines. Several DEGs including ethylene-responsive transcription factor (ERF), constitutive triple response (CTR) (in ethylene signaling pathway), monodehydroascorbate Reductase (MDAR), NADPH oxidase (in ROS pathway), cytochrome c oxidase assembly protein (COX) (in NO pathway) up-regulated in 'J8634-B-30'. These outcomes provided the valuable information for further exploring the genetic mechanism of waterlogging tolerance in rapeseed.