• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.259-259
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• 2005

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.78-83
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• 2006

A simplex-lattice mixture design was applied to blend three varieties of rice; Ilpum (IP), Goami2 (G2) and Baegjinju (BJJ) all of which have very different physicochemical properties from one another. G2 and BJJ are mutant rice developed from IP. Increasing G2 portions in a rice blend increases indigestible carbohydrate contents. Blending at least 33.3% of G2 to either IP or BJJ increased indigestible carbohydrates, which were approximately $3.55{\pm}1.31\;to\;4.57{\pm}0.37$(g/100 g), respectively. Consumers rated higher than 6.0 (=like slightly) for the IP alone and binary blends of IP and BJJ, whereas less than 5.0 (=dislike moderately) for the blends containing G2 rice, indicating that consumers would not accept rice blends containing higher G2 portions. However, although blends with G2 were given lower consumer ratings, a rice blend with G2 could have health benefits in terms of nutritional and functional properties due to the higher indigestible carbohydrate contents.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.17-22
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• 2008

Aromatic rice has become popular owing to its aroma. Growing demand for aromatic rice has spurred interest in the development of domestic cultivars that offer similar combinations of grain attributes such as texture, cooking characteristics, aroma, and taste. In this study, the most important agronomic attributes and aroma of 26 cultivars from Afghanistan, Iran, and Uzbekistan, and controls from Japan, Thailand, and India were characterized. Also $F_2$ populations derived from the cross between(Jasmine 85 aromatic$\times$Nipponbare non-aromatic) and(Jasmine 85$\times$Basmati 370 aromatic) were obtained. Tasting individual grains, cooking test, 1.7% KOH sensory test, and molecular marker analysis have been applied to distinguish between aromatic and non-aromatic rice. Diversity for some traits of agronomic importance, such as plant height was detected among countries, e.g. Afghan cultivars classified as tall, and Iranian and Uzbek intermediate and short, respectively. Differentiations of panicle, grain, leaf, basal internode, and culm dimension among rice cultivars, indicating the source of rice diversity in Central Asia. According to the results, 6 of 10, 2 of 7, and 0 of 6 of Afghan, Iranian, and Uzbek rice cultivars were scored as aromatic, respectively. Therefore, Afghan cultivars are a good source of aromatic rice germplasm for Central Asia. The expression between aromatic and non-aromatic, and aromatic and aromatic combinations has been evaluated. The observed segregation ratio of these crosses in the $F_2$ populations was tested by $x^2$ analysis against the expected ratio for a single gene. A segregation ratio of 3:1 between non-aromatic and aromatic combination has been detected, while segregation has not been detected between the aromatic and aromatic combinations. Also, parallel results were obtained from the tested aromatic rice cultivars. Thus, our results suggest that a single recessive gene controls aroma in all aromatic rice cultivars.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.110-110
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• 2022

Rice is the world's most important food crop and a major source of nutrition for about two thirds of populations. Northern Vietnam is one of the most important centers of genetic diversity for cultivated rice. In this study, we determined the genetic diversity and population structure of 79 rice landraces collected from northern Vietnam and 19 rice accessions collected from different countries. In total, 98 rice accessions could be differentiated into japonica and indica with moderate genetic diversity and a polymorphism information content of 0.382. We also detected subspecies-specific markers to classify rice (Oryza sativa L.) into indica and japonica. Additionally, we detected five marker-trait associations and rare alleles that can be applied in future breeding programs. Most interestingly, analysis of molecular variance (AMOVA) found genetic differentiation was related to geographical regions with an overall PhiPT (analog of fixation index FST) value of 0.130. More emphasis was given to provide signatures and infer explanations about the role of geographical isolation and environmental heterogeneity in genetic differentiation among regions in landraces from northern Vietnam. Our results suggest that rice landraces in northern Vietnam have a dynamic genetic system that can create different levels of genetic differentiation among regions, but also maintain a balanced genetic diversity between regions.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.364-371
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• 2017

The key to development of barnase-barstar transgene based hybrid seed technology is the availability of tightly regulated tapetum specific promoter, as any leaky expression of the barnase gene leads to several unintended effects. In the present study, we used two different tapetum specific promoters i.e. promoter of the RTS gene isolated from rice cultivar IR64 and the OsG6b promoter from japonica rice cultivar Hayayuki to express the barnase gene in rice transgenic lines. While viable male sterile transgenic lines could not be obtained with RTS promoter we could develop single copy male sterile lines when the barnase gene was expressed under the OsG6b promoter.

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.197-206
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• 2000

This paper summarizes recent developments in the field of molecular biology and its application to plant breeding, particularly in rice. Plant breeding in the past mostly depended on the time-consuming crossing of known genomes limited to certain traits. Plant breeding has now benefited from marker-assisted selection and genetic engineering to widen the gene pool, improve plant protection, and increase yield. Future plant breeding will expand based on functional and nutritional genomics, in which gene discovery and high-throughput transformation will accelerate crop design and benefits will accrue to human health, in the form of nutritional food for poor people to reduce malnutrition, or food enriched with antioxidants and with high food value for rich people. Agricultural biotechnology for food is no longer a dream but a reality that will dominate the 21st century for agriculture and human welfare.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.281-291
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• 2010

The rice CHLH gene encodes the $Mg^{2+}$-chelatase H subunit, which is involved in chlorophyll biosynthesis. Growth of the chlorophyll-deficient oschlh mutant is supported by mitochondrial activity. In this study, we investigated the activity of mitochondrial respiration in the illuminated leaves during oschlh seedling development. Growth of mutant plants was enhanced in the presence of 3% sucrose, which may be used by mitochondria to meet cellular energy requirements. ATP content in these mutants was, however, significantly lowered in light conditions. Low cytosolic levels of NADH in illuminated oschlh mutant leaves further indicated the inhibition of mitochondrial metabolism. This down-regulation was particularly evident for oxidative stressresponsive genes in the mutant under light conditions. Hydrogen peroxide levels were higher in oschlh mutant leaves than in wild-type leaves; this increase was largely caused by the impairment of the expression of the antioxidant genes, such as OsAPXl, OsRACl, and OsAOXc in knockout plants. Moreover, treatment of mesophyll protoplasts with ascorbic acid or catalase recovered ATP content in the mutants. Taken together, these results suggest that the light-mediated inhibition of mitochondrial activity leads to stunted growth of CHLH rice seedlings.

• Molecules and Cells
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• v.21 no.3
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• pp.360-366
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• 2006

Up to 35% of the rice genome consists of various kinds of transposons, and CACTA and MITE are two of the major class 2 DNA transposons in the genome. We have employed the consensus sequences of Rim2/Hipa CACTA, Stowaway MITE Pangrangja, and Tourist MITE Ditto for transposon display (TD) analysis to locate them on a genetic map, with 58 SSR markers used to anchor them. The TD analysis produced a high profile of the polymorphisms between the parental lines, Oryza sativa var. Gihobyeo/O. sativa var. Milyang, in intraspecific $F_{15}$ RIL lines, locating 368 markers of Rim2/Hipa CACTA, 78 markers of Tourist MITE Ditto, and 22 markers of Stowaway MITE Pangrangja. In the segregation analysis, non-parental segregating bands and segregation distortion bands were observed. The recombinant genetic map spans 3023.9 cM, with 5.7 cM the average distance between markers. The TD markers were distributed unequally on the chromosomes because many TD markers were located in pericentric chromosomal regions except in the cases of chromosomes 2, 3, 6 and 9. Although the number of transposon markers was not sufficient to include all rice class 2 transposons, the current map of CACTA and MITE transposons should provide new insight into the genome organization of rice since no previous DNA transposon map is available.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.10a
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• pp.14-27
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• 2003

The genomes of Arabidopsis and rice have been fully sequenced. Genomic sequencing provides global information about genome structure and organization. A comprehensive research account of our recent studies conducted on genome painting, comparative genomics and genome fusion is provided in order to project the prospects of plant cytogenetic research in post-genomics era. Genome analysis by GISH using genome painting is demonstrated as an excellent means suitable for visualization of a whole genome, since total genomic DNA representing the overall molecular composition of the genome is used as a probe. FISH on extended DNA fibers has been developed for high-resolution FISH and has contributed to determining the copy number and order of genes. We have also mapped a number of genes involving starch synthesis on wheat chromosomes by FISH and compared the position of these genes on linkage map of rice. Macro synteny between wheat and rice can be observed by comparing the location of these genes in spite of the fact that the size of DNA per chromosome differs by 20 fold in two. Moreover, to approach our goal towards making bread and udon noodles from rice flour in future by incorporating bread making and the noodle qualifies in rice, we have been successful in introducing large genomic DNA fragments containing agronomically important genes of wheat into a rice by successive introduction of large insert BAC clones, there by expanding genetic variability in rice. We call this method genome fusion.

• Interdisciplinary Bio Central
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• v.2 no.4
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• pp.13.1-13.8
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• 2010

The National BioResource Project of Japan is a governmental project to promote domestic/international research activities using biological resources. The project has 27 biological resources including three cereal resources. The core center and sub-center which historically collected the cereal resources were selected for each cereal program. These resources are categorized into several different types in the project; germplasm, genetic stocks, genome resources and database information. Contents of rice resources are wild species, local varieties in East and Southwest Asia & wild relatives, MNU-induced chemical mutant lines, marker tester lines, chromosome substitution lines and other experimental lines. Contents of wheat resources are wild strains, cultivated strains, experimental lines, rye wild and cultivated strains; EST clones and full-length cDNA clones. Contents of barley resources are cultivar and experimental lines, core collection, EST/cDNA clones, BAC clones, their filters and superpool DNA. Each resource is accessible from the online database to see the contents and information about the resources. Links to the genome information and genomic tools are also important function of each database. The major contents and some examples are presented here.