• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.378-383
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• 2005

This study was conducted in order to exam­ine relationships between the viviparous germination ability and the antioxidative system in rice seeds and seedlings. Enzyme activities was compared among the four varieties with different viviparous germination ability from the early or mid-late maturity group. $\alpha$-Amylase activities correlated with the viviparous germination rate (VGRs) and $\alpha$-amylase activity in seeds of 40 days after heading (DAH) was highest in Dongjinbyeo among mid­late maturing varieties (MLMVs) and in Daeseongbyeo among EMVs. $\alpha$-Amylase activity in dry mature seeds was also higher in varieties with higher VGR. Glucose contents in viviparously germinating seeds and mature dry, seeds were higher in varieties with higher VGRs. Cat-alase activities did not correlate with the VGRs in both maturity groups. However, peroxidase activities in viviparously germinating seeds were higher in varieties with higher VGRs.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.256-257
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• 2000

• Proceedings of the Korean Society of Crop Science Conference
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• 1995.05a
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• pp.94-95
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• 1995

• Proceedings of the Korean Society of Crop Science Conference
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• 1999.05a
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• pp.9-11
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• 1999

• Current Research on Agriculture and Life Sciences
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• v.22
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• pp.1-12
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• 2004

Pod-edible bean or snap bean is a fairly new crop to domestic farmers but the national demand is steadily increasing in recent years along with the development of western food business and change in dietary patterns. At the same time, much efforts are being made to export it to foreign country, mainly to Japan. The amount of seeds introduced from outside is also continuously increasing along with the enlargement of area planted for the crop. Hybridization breeding for the crop has already been started to supply the cheaper and better seeds which will reduce the seed costs and foster the higher income to the farmers. In this experiment, several technologies related with the production of quality seeds are preliminary investigated. Some of the results obtained are summarized as follows; 1. Highly significant interaction was recognized between planting dates and no. of pods per plant and no. of branches but no interaction between planting dates and plant height and no. of nodes on main stem. Days to maturity was proportionally reduced to later planting dates. 2. Rate of viviparous pods and seeds was gradually increased in later planting dates but rate of germination was increased in earlier planting dates with lower germination rate in white seed coat grains than in colored seed ones. 3. Seed yield was higher in the earlier planting dates with a great deal of varietal difference. Early to mid April was considered to he the optimum planting dates for snap bean in Kyungbuk area. High correlation was recognized between seed yield and no. of pods per plant, no. of seeds per plant, and 100 seed weight. 4. Days to flowering was three and seven days longer in Cheongsong, high mountainous area than in Kunwi, somewhat prairie lowland. One hundred seed weight was also higher in Cheongsong than in Kunwi. Rate of viviparous grains, pods, and decayed seeds was higher in Cheongsong but, at the same time, the rate of germination and seed yield was also higher in Cheongsong. 5. One hundred seed weight of KLG5007 increased continuously up to 35days after flowering and decreased thereafter but that of KLG50027 increased to 40days after flowering and slowly reduced thereafter. The content of crude oil reached to maximum at 40 days after flowering and reduced thereafter. The rate of germination in Gangnangkong 1 was the highest, 89.3%, at 35 days after flowering and reduced thereafter while that in KLG50027 reached to maximum, 70.7%. at 40days after flowering and reduced thereafter. Thus, the optimum harvesting time for snap bean was considered to be 35~40days after flowering. 6. The snap bean pods at yellow bean stage easily became viviparous ones under saturated moisture conditions for 24 hours at $25{\sim}30^{\circ}C$. Therefore, it is recommended to harvest pods somewhat earlier than yellow-bean stage and let them do post maturing, especially when it is to be rained.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.283-283
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• 2022

Abiotic stresses such as high/low temperature, drought, salinity, and submergence directly or indirectly influence the physiological status and molecular mechanisms of rice which badly affect yield. Especially, the low temperature causes harmful influences in the overall process of rice growth such as uneven germination and the establishment of seedlings, which has become one of the main limiting factors affecting rice production in the world. It is of great significance to find the candidate genes controlling low-temperature tolerance during seed germination and study their functions for breeding new rice cultivars with immense low-temperature tolerance during seed germination. In this study, 120 lines of Cheongcheong/Nagdong double haploid population were used for quantitative trait locus analysis of low-temperature germinability. The results showed significant difference in germination under low different temperature conditions. In total, 4 QTLs were detected on chromosome 3, 6, and 8. A total of 41 genes were identified from all the 4 QTLs, among them, 25 genes were selected by gene function annotation and further screened through quantitative real time polymerase chain reaction. Based on gene function annotation and level of expression under low-temperature, our study suggested OsGPq3 gene as a candidate gene controlling viviparous germination, ABA and GA signaling under low-temperature. This study will provide a theoretical basis for marker-assisted breeding.

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.02a
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• pp.30-31
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• 1988

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.1
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• pp.1-8
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• 2000

The objectives of this study were to investigate weather conditions which induced discolored grains and viviparous germination, and to evaluate yield responses following viviparous germination during mid- and late- ripening stage, the submergence during reproductive growth stage, and lodging in the yellow ripe stage. Weather conditions which caused glume discoloration at heading stage were 21.3-26.4$^{\circ}C$ in average temperature, 75.2-98.4% in relative humidity, 19.3 in transpiration coefficient and 10.8-13.8 m/sec. in wind speed. Yield reduction was 26-27% and 10~17%, respectively, when the glume discoloration rates were 63.2-65.7% and 38.3-45.2%, obviously due to the decrease in percent of fertile grain and ripening ratio. Weather conditions during continuous rain for 7 days were 96% in relative humidity, 18.9$^{\circ}C$ in average temperature, 21.9$^{\circ}C$ in maximum temperature, and 16.8$^{\circ}C$ in minimum temperature, causing the most viviparous germination in Juanbyeo(45.5%), followed by Jinbubyeo(14.5%), Bongkwangbyeo(14.2%), and Obongbyeo(12.6%). Lateral tillers started to occur when the submergence at the depth of 1.5-2 m lasted one day during the reproductive growth stage. The submergence for 2-3 days at 3-4 m of water depth induced 269-571 lateral tillers/m$^2$, supporting 32-52% of the total yield. The rice yield in the paddy fields which were left under the lodging conditions until harvesting was not different compared to that of the paddy fields which were kept upright by tieing them together after lodging, but perfect grain ratio decreased about 9.1% in the transplanting culture and 12.5% in the direct seeding culture on dry paddy field because of the increase in immature grains.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.90-90
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• 2017

Regulation of seed dormancy is important in many grains to prevent pre-harvest sprouting. To identify and understand the gene related to seed dormancy regulation, we have screened for viviparous phenotypes of rice mutant lines generated by insertion of Ds transposon in a Korean Japonica cultivar (Dongjin) background. One of the mutants, which represented viviparous phenotype, was selected for further seed dormancy regulation studies and designated dor1. The dor1 mutant has single Ds insertion in the second exon of OsDor1 gene encoding glycine-rich protein. The seeds of dor1 mutant showed a higher germination potential and reduced abscisic acid (ABA) sensitivity compared to wild type Dongjin. Over-expression of Dor1 complements the viviparous phenotype of dor1 mutant, indicating that Dor1 function in seed dormancy regulation. Subcellular localization assay of Dor1-GFP fusion protein revealed that the OsDor1 protein mainly localized to membrane and the localization of OsDOR1 was influenced by presence of a giberelin (GA) receptor OsGID1. Further bimolecular fluorescence complementation (BiFC) analysis indicated that OsDOR1 interact with OsGID1. The combined results suggested that OsDOR1 regulates seed dormancy by interacting with OsGID1 in GA response. Additionally, expression of OsDOR1 partially complemented the cold sensitivity of Escherichia coli BX04 mutant lacking four cold shock proteins, indicating that OsDOR1 possessed RNA chaperone activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.103-107
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• 2000

The viviparity of 28 rice varieties was tested at 25 days after heading(DAH), 35DAH, and 45DAH in the laboratory and field condition for 12 days. The incubation temperature was 20/l$0^{\circ}C$ (day/night), 25/15$^{\circ}$C$ and 30/20$^{\circ}$C$ in the laboratory test, and under field water conditions in the field test. The biggest varietal difference of viviparity was found in the laboratory test when examined at 45DAH with the 6-day incubation under 25/15$^{\circ}$C$ . At this conditions the mean viviparous ratio was 32.1 % with the range of 53.9 and the variance of 259.5. In the field test, the significant varietal difference in the viviparity was also found in the lodging treatment at 45 DAH for 6 days. Correlation coefficient analysis between the field and laboratory tests was highly significant from 4 days after incubation at 45 DAH and after 6-day incubation at 35 DAH, and correlation coefficient was higher as incubation days in the laboratory and submerged days under field water became longer. Considering the correlation between the field and laboratory tests, varietal difference of viviparity and convenience of testing, the laboratory test at 45 DAH for 6-day incubation under 25/15$^{\circ}$C$ was the most efficient evaluation method for the viviparity of rice cultivar.