• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.163-170
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• 2008

The detection, characterization and use of quantitative traits loci, QTL, have significant potential to improve the efficiency of selective breeding of species. Therefore, a population with 59 advanced backcross lines($BC_2F_5$), derived from a cross between IR64 and Tarome molaei, were studied in Tonekabon Rice Research Station of Iran in order to map QTLs for panicle length, number of grain per panicle, and panicle grain sterility in rice. The parental screening wtih 235 SSR markers in agarose and polyacrylamide gels revealed 114 markers with clear polymorphic bands. To search for QTLs associated with panicle length, number of grain per panicle, and panicle grain sterility, we constructed a genetic linkage map using 114 microsatellite markers. Positive and negative transgressive segregations were observed in $BC_2F_5$ lines for all traits. Using multiple interval mapping(MIM), a total of 20 putative QTLs were detected, of which eight were for panicle length, three for number of grains, and nine for panicle grain sterility. The maximum number of QTLs were mapped on chromosomes 1 and 2 with eight QTLs. These QTL markers could possible be utilized for marker-assisted selection.

• Journal of the Korean Dietetic Association
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• v.3 no.2
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• pp.105-111
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• 1997

The inhibitory effect of rice(Oryza sartiva L., illpumbyeo) against mutagenicity induced by tryptophan pyrolysates were investigated using Salmonella typhimurium reversion assay. Both methanol extracts of obtained from brown and white rice were found to possess strong activites of inhibiting the mutagenicities of 3-amino-1,4-dimethyl-5H-pyriod[4,3-b]indol(Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indol(Trp-P-2) on Salmonella typhimurium reversion assay. As the concentration of methanol extract increased, inhibitory effect on mutagenicity increased but reached at steady state as inhibition rate of 90% when the concentration was above 10mg/plate. There was no significant difference(p>0.05) in inhibitory effect of methanol extracts between brown and white rice against tryptophan pyrolysates.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.441-445
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• 2000

In order to improve phosphate use efficiency of rice using phosphate transporter (PT), transgenic rice plants containing a tobacco PT gene were developed. Calli from Dongjinbyeo (Oryza sativa L.) were cocultured with A. tumefaciens LBA 4404 harboring PT gene. Multiplied calli were transferred to MS medium supplemented with 50 mg/L hygromycin, 500 mg/L carbenicillin, 2 mg/L kinetin, 0.1 mg/L NAA. After 2 weeks, hygromycin resistant shoots were obtained from the calli on the selection medium. The putative transgenic shoots were transferred to rooting MS medium supplemented with 250 mg/L cabenicillin. Plant regeneration rate from the calli was about 52%. Stable incorporation of the tobacco PT gene into rice genomic DNA was confirmed by PCR and Southern blot analysis.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.97-101
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• 2001

The transport and allocation of photosynthetic assimilate is an important regulatory factor in plant productivity, In order to modify assimilate partitioning in rice, transgenic plants containing a potato sucrose transporter (SuT) gene were developed. Calli derived from rice seeds (Oryza sativa L. cv Dongjin) were cocultured with A. tumefaciens LBA 4404 harboring the SuT gene. Calli were transferred to MS medium supplemented with 50 mg/L hygromycin, 500 mg/L carbenicillin, 2 mg/L kinetin, 0.1 mg/L NAA. After 2 weeks, hygromycin resistant shoots were obtained from the calli on the selection medium. Roots were induced from the putative transgenic shoots on rooting MS medium supplemented with 250 mg/L cabenicillin. Plant regeneration rate from the calli was about 150%. Stable incorporation of the potato SuT gene into rice genomic DNA was confirmed by PCR and Southern blot analysis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.335-335
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• 2017

Recently NERICA (New Rice for Africa) was developed by a crossing of African rice (Oryza glaberrima Steud.) and Asian rice (Oryza sativa L.) in West Africa, and is considered to be drought resistant, but drought resistance of NERICA and differences between Asian rice are not clarified enough. In this research, NERICA (four cultivars and two lines), Asian rice (three cultivars and sativa parent of NERICA) and African rice (glaberrima parent of NERICA) were cultivated in the field in Shizuoka University under drought and traits of each cultivar and line relevant to drought resistance, stomatal conductance by porometer, soil water content of individual depths by TDR method, SPAD values by SPAD meter and leaf thickness by micrometer, were measured and compared with dry matter production and yield. Effects of compost were also compared among sativa parent, one NERICA cultivar and two NERICA lines. Glaberrima parent showed highest top dry weight. One NERICA line, one drought resistant Asian rice cultivar and sativa parent, showed higher top dry weight and yield (ear weight) than other Asian rice cultivars and NERICA cultivars and line tested. Compost tended to increase top dry weight and yield in one of NERICA line and sativa parent. But in one NERICA cultivar and line, top dry weight and yield were not increased. In one of Asian rice, one of NERICA line and sativa parent that showed high top dry weight and yield, stomatal conductance was high. On the contrary the glaberrima parent and in other NERICA cultivars and line it was low. In sativa parent compost increased stomatal conductance but in NERICA cultivar and lines it was not. Among cultivars and lines that showed high top dry weight and yield sativa parent and one of NERICA line SPAD value and leaf thickness were high but in one of Asian rice and glaberrima parent they were low. Cultivar and line differences in yield and top dry weight among Asian rice and NERICA were significantly correlated with those in stomatal conductance ($r=0.778^{**}$ and $r=0.654^*$, respectively) and those in leaf thickness ($r=0.600^*$ and $r=0.640^*$, respectively). In Asian rice cultivars average soil water content was significantly correlated with yield ($r=0.886^*$) but in NERICA cultivars and lines it was not significant correlated (r= -0.256). Cultivar and line differences in leaf thickness were significantly correlated with SPAD value ($r=0.773^{**}$). In Asian rice cultivars it was significantly correlated ($r=0.962^{**}$), but in NERICA cultivars and lines it was not significantly correlated (r=0.559). Asian rice cultivars tended to consume soil water to increase yield but in NERICA cultivars and lines the tendency was not clear. Correlation between SPAD value and leaf thickness was different between Asian rice and NERICA cultivars and lines, and in Asian rice cultivars it was significantly correlated but in NERICA cultivars and lines it was not significant. Importance of maintaining high stomatal conductance by high leaf thickness was clarified.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.23-23
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• 2017

Rice (Oryza sativa L.) is the world's most important cereal crop. In crop plant, chlorophyll content and leaf senescence could affect grain filling and yield. We analyzed a QTL associated with chlorophyll content and delayed leaf senescence using high chlorophyll near isogenic line (HC-NIL). HC-NIL derived from a cross between Oryza sativa cv. Hwaseong as a recurrent parent and wild species O. grandiglumis as a donor parent showed higher chlorophyll content than Hwaseong. To identify QTL associated with chlorophyll content, 58 $F_3$ and 38 $F_4$ lines were developed from a cross between HC-NIL and Hwaseong. For QTL analysis, simple sequence repeat (SSR) markers were used for genotyping and one-way ANOVA was conducted. A QTL for chlorophyll content (qCC2) was detected in chromosome 2 and explained 24.63% of phenotypic variation. The senescence effect of the qCC2 was examined in dark-induced incubation (DII). Detached leaves from Hwaseong and HC-NIL were incubated on 3mM MES buffer (pH 5.8) at $27^{\circ}C$ under complete dark condition. After 3 days of incubation, the Hwaseong leaves turned yellow, but the HC-NIL leaves were green. HC-NIL has higher chlorophyll content with delayed senescence than Hwaseong. These results indicated that qCC2 is associated with stay-green phenotype. To know whether the qCC2 is responsible for leaf functionality, ion leakage test and Fv/Fm measurement were performed. Both experiment results showed that differences were observed between Hwaseong and HC-NIL but it was not statistically significant. These results might suggest that the qCC2 is possibly related to chlorophyll content and non-functional stay-green phenotype.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.384-391
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• 2008

Rice blast disease, caused by the pathogenic fungus Magnaporthe grisea, is a serious issue in rice (Oryza sativa L.) growing regions of the world. Transcript profiling in rice inoculated with the fungus has been investigated using the transcriptomics technology, serial analysis of gene expression (SAGE). Short sequence tags containing sufficient information which are ten base-pairs representing the unique transcripts were identified by SAGE technology. We identified a total of 910 tag sequences via the GenBank database, and the resulting genes were shown to be up-regulated in all functional categories under the fungal biotic stress. Compared to the compatible interaction, the stress and defense genes in the incompatible interaction appear to be more up-regulated. Particularly, thaumatin-like gene (TLP) was investigated in determining the gene and protein expression level utilizing Northern and Western blotting analyses, resulting in an increase in both the gene and the protein expression level which arose earlier in the incompatible interaction than in the compatible interaction.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.40-40
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• 2017

Rice (Oryza sativa L.) is one of major crops of Vietnam. Rice plant contains many secondary metabolites that are potent to inhibit growth of other plants. This study was carried out to find potential plant growth inhibitors from rice plants. Seven rice varieties were cultivated in the fields affiliated to Hiroshima University, Japan; Mature stems and leaves from each variety were collected, and then they were extracted with methanol, hexane, ethyl acetate, butanol, and water. Total phenolic content and total flavonoid content were the highest in ethyl acetate extract. DPPH antioxidant assay results showed that the ethyl acetate extract also had higher $IC_{50}$ value. Therefore, the ethyl acetate extracts were selected for laboratory bioassay. Results showed that the two-local variety Re nuoc and Nan chon inhibited the germination of radish and barnyard grass seedlings at the greatest levels, as compared to other cultivars. HPLC quantification indicated that the ethyl acetate extracts of Re nuoc and Nan chon rice plant parts consists of phenolic and flavonoids compounds which are potent as plant growth inhibitors. Further laboratory bioassay and field experimentation will be conducted to validate the laboratory bioassay findings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.161-167
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• 1998

Root and shoot development of two rice (Oryza sativa L.) cultivars with different genetic backgrounds was studied with reference to their relative growth. Tongil type (indica-japonica hybrid) cultivar 'Kuemkangbyeo' and japonica cultivar 'Koshihikari' were grown in $5000^{-1}$ a Wagnar pots under flooded condition. Three plants with roots of both cultivars were taken in every phyllochron through the heading stage to record morphological characteristics of shoot and root system. Compared to Koshihikari, Kuemkangbyeo produced more tillers and had greater shoot weight and leaf area per hill. Length and weight of the root system in both cultivars increased exponentially with time. At the same time, root system development was significantly faster in Kuemkangbyeo than in Koshihikari after the panicle initiation stage. As a result, Kuemkangbyeo has a vigorous root system which consists of larger number of nodal roots compared to Koshihikari. Also, the root length and weight per unit leaf area of Kuemkangbyeo were larger than those of Koshihikari in the later half of growing period, which suggests possible higher physiological activity of the root system of Kuemkangbyeo which is known as a high-yielding cultivar. The relationship between root traits (crown root number, total root length, and root dry weight) and shoot traits (leaf area and leaf+culm dry weight) in both cultivars closely showed allometry until the flag leaf stage.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.90-94
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• 1995

Post emergence herbicidal activities$(pI_{50})$ of X-substituted phenylvinylsulfone derivatives(S) in-vivo against rice(Oryza sativa L.), Barnyard grass(Echinochloa crus-galli) and Pickerelweed(Monochoria vaginalis Presl) were measured by the pot test under paddy conditions. The (S) showed herbicidal symptom rapidly with lower activity(average $pI_{50}=2.0$) as proherbicide, which was excellent tolerance to rice. The structure activity relationships(SAR) were analyzed using such a physicochemical parameters as hydrophobic$({\pi})$ and molecular orbital(MO) quantity by the multiple regression technique, and discussed with quantum pharmacology. The herbicidal activities were related to the hydrophobic$({\pi})$ effect of X-substituent and orbital(HOMO & LUMO) energy. In case of Pickerelweed, the effect was rationalized by parabolic function of ${\pi}$ constant, where the optimal value of ${\pi}$ was 1.10. An increase in hydrophobicity and negative orbital energy by the electron attracting X-substituent may contribute to the herbicidal activity. Based on results proposed from SAR analysis, the mode of herbicidal action could be assumed.