• Proceedings of the Korean Society of Crop Science Conference
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• 2021.10a
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• pp.18-18
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• 2021

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.34-34
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• 2022

Capacity building for bioinformatics could be achieved with the systematic training of research staff and higher degree students in the current best practices for analysis of data from 'omic-type experiments. It is anticipated that the KOICA-University of the Philippines Los Baños - International Rice Research Insitute Agricultural Genomics Research Center activities will focus on the use of next generation sequencing technology for genome sequencing and annotation, genome variant discovery for use in GWAS and QTL mapping, and transcriptome analysis of organisms important to agriculture and food security. Such activities require that researchers have high levels of knowledge and skills in bioinformatics in order to gain insights from the results of the experiments performed. In this talk the bioinformatic tools/solutions and online training materials already available will be presented, as well the upcoming resources under development in support of the project.

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.35-36
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• 1998

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.554-564
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• 2006

It is important to understand pedigree of rice cultivars commonly used for breeding. In this paper, pedigree tables for tracking the pedigree of 17 representative rice cultivars recommended by Rural development Adminstration (RDA) were completed and analyzed using two kinds of web database system; 'IRIS' and 'RRDB'. Seven cultivars, namely, 'Sangmibyeo', 'Ilpumbyeo', 'Saegewhabyeo', 'Surabyeo', 'Shindongjinbyeo', 'Ilmibyeo' and 'Jungwhabyeo' had 'Koshihikari' on the pedigree of their ancestor. Besides 'Koshihikari', the most feguently used ancestral germplasms among the high quality rice cultivars were 'Fujisaka 5', 'Kameno o' and 'Asahi', 'Fujisaka 5' was used as ancestral parent in 12 out of 17 cultivars. Interestingly, 'Kameno o' was used in pedigree of 16 out of 17 high quality varieties and 'Asahi' was used in the ancestral pedigree of all 17 varieties. 'Hwayeongbyeo' was used as one of parent in the breeding of 'Dongjin 1', 'Hwabongbyeo', 'Saegewhabyeo' and 'Junambyeo'. 'Ilpumbyeo' was used in the breeding pathway of 'Junambyeo' and 'Saegewhabyeo', 'Mangeumbyeo' itself was not enlisted as one of high quality rice cultivars, but was used as a breeding parent of three high quality varieties, namely, 'Saegewhabyeo', 'Hwabongbyeo' and 'Nampyeongbyeo'. Incorporated with evaluation data, pedigree will provide a valuable chance to genealogical tracking of agronomic traits such as disease resistance, grain quality and etc.

• The Plant Pathology Journal
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• v.37 no.2
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• pp.200-203
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• 2021

Rice blast caused by the filamentous fungus Magnaporthe oryzae, is arguably the most devastating rice disease worldwide. Development of a high-throughput and reliable field blast resistance evaluation system is essential for resistant germplasm screening, resistance genes identification and resistant varieties breeding. However, the occurrence of rice blast in paddy field is easily affected by various factors, particularly lack of sufficient inoculum, which always leads to the non-uniform occurrence and reduced disease severity. Here, we described a procedure for adequately inducing the occurrence of rice seedling blast in paddy field, which involves pretreatment of diseased straw, initiation of seedling blast for the first batch of spreader population, inducing the occurrence of the second batch of spreader population and test materials. This procedure enables uniform and consistent infection, which facilitates efficient and accurate assessment of seedling blast resistance for diverse rice materials.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.326-332
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• 2008

This study was conducted to evaluate an early-maturing rice cultivars adaptable to early transplanting cultivation in Yeongnam plain area. High temperature during the ripening stage of paddy rice under the early-transplanting cultivation in Yeongnam plain was to influence in several agronomic traits such as number of spikelet, ripening ratio, grain appearance of milled rice, and yield. 'Gounbyeo' and 'Junghwabyeo' were better than the others in grain appearance of milled rice and ripening ratio, but their yield potential were lower than that of the other varieties. Moreover, 'Gounbyeo' and 'Junghwabyeo' showed high ratio of broken rice. 'Unkwangbyeo' was the highest in yield and eating quality among the tested varieties, but also high percentage of white core and belly in milled rice. Therefore, in order to recommend those cultivars to farmers, it should be needed to establish an optimal cultivation method, such as transplanting density, fertilizer application, and harvesting time, etc. consequently, it should also be required to develop a new varieties with high ripening capability under high temperature condition.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.13-13
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• 2017

By the progress of genome sequencing, infrastructures for marker-assisted breeding (MAB) of rice came to be established. Fine mapping and gene isolation have been conducted using the breeding materials derived from natural variations and artificial mutants. Such genetic analysis by the genome-wide dense markers provided us the knowledge about the many genes controlling important traits. We identified several genes or quantitative trait loci (QTL) for heading date, blast resistance, eating quality, high-temperature stress tolerance, and so on. NILs of each gene controlling heading date contribute to elongate the rice harvest period. Determination of precise gene location of blast resistance gene pi21, allowed us to overcome linkage drag, co-introduction of undesirable eating quality. We could also breed the first practical rice cultivar in Japan with a brown planthopper resistance gene bph11 in the genetic back-ground of an elite cultivar. Discovery of major and minor QTLs for good eating quality allowed us to fine-tune of eating quality according to the rice planting area or usage of rice grain. Many rice cultivars have bred efficiently by MAB for several traits, or by marker-assisted backcross breeding through chromosome segment substitution lines (CSSLs) using genetically diverse accessions. We are also systematically supporting the crop breeding of other sectors by MAB or by providing resources such as CSSLs. It is possible to pyramid many genes for important traits by using MAB, but is still difficult to improve the yielding ability. We are performing a Genomic Selection (GS) for improvement of rice biomass and grain yield. We are also trying to apply the genome editing technology for high yield rice breeding.

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.05a
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• pp.17-25
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• 2003

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.613-618
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• 1989

Tirteen rice varieties of Japonica-Indica briefing type (J-I breeding type) and ten of Japonica type produced in Korea in 1985 were studied on cooking quality of milled rice and texture of cooked rice. The results are as follows: in the Looking quality, water uptake ratio of cooked rice and total solid in residual liquid showed significant $(p<2.172^*\;and\;2.419^*,\;respectively)$ between J-I breeding type and Japonica type The water uptake ratio of cooked rice was higher J-I breeding type than Japonica type but the total solid and intensity of iodine blue value in residual liquid were lower J-I breeding type than Japonica type. Minimum cooking time of milled rice showed significant $(p<2.375^*)$ between J-I breeding type and Japonica type for texture of cooked rice. The cooking time of J-I breeding type shorter than Japonica type. Hardness and cohesiveness in texture of cooked rice appeared to be significant cant $(p<4.370^{***}\;and\;2.371^*,\;respectively)$ between J-I breeding type and Japonica type, and then hardness was higher Japonica type than J-I breeding type, but cohesiveness was lower Japonica type than J-I breeding type. The correlation coefficients between amylose content and adhesiveness of varieties in the same type was $-0.922^{**}$ in J-I breeding type and $-0.915^**}$ in Japonica type. The correlation coefficients between protein content and hardness of the varieties in the same type was $0.954^{**}$ in Japonica type and so denoted as positive correlation. And the scatter diagram between protein and hardness could be divided into J-I breeding type and Japonica type.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.292-292
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• 2022

Since 1992, the Rural Development Administration (RDA), Republic of Korea in collaboration with International Rice Research Institute (IRRI) has developed 6 japonica rice varieties(MS11, Japonica 1, 2, 6, 7 and Cordillera 4) that are adaptable to tropical regions. However, these varieties show moderate resistance or susceptibility to certain biotic and abiotic stress. The development of varieties with more stable forms of resistance is highly desirable, and this could be possibly achieved through rapid introgression of known biotic and abiotic resistant genes. In this study, we analyzed the allele types of major biotic stress resistant genes including Xa5, Xa13, Xa21 and Xa25 for bacterial leaf blight, Pi5, Pi40, Pish and Pita2 for blast, tsv1 for rice tungro spherical virus, and Bph6, Bph9, Bph17, Bph18 and Bph32 for brown planthopper by using gene-specific molecular markers. In addition, seed quality related genes Sdr4 for preharvest sprouting and qLG-9 for seed longevity were also analyzed. The results revealed that2h5 and Xa25 resistance alleles showed in all varieties while Pi5 resistance allele showed only in MS11. The Pish resistance allele were present in five varieties except for Japonica 1. Meanwhile, for the rest of the genes, no presence of resistance alleles found in six varieties. In conclusions, most of tropical japonica varieties are lack of the major biotic stress resistant genes and seed quality genes (Sdr4 and qLG-9). Moreover, the results indicated that rapid deployment of a few major genes in the current tropical japonica rice varieties is urgent to increase durability and spectrum of biotic stress resistance and also seed dormancy/longevity which are essential traits for tropical environments.