• Molecules and Cells
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• v.37 no.2
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• pp.149-160
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• 2014

Plant breeders have focused on improving plant architecture as an effective means to increase crop yield. Here, we identify the main-effect quantitative trait loci (QTLs) for plant shape-related traits in rice (Oryza sativa) and find candidate genes by applying whole genome re-sequencing of two parental cultivars using next-generation sequencing. To identify QTLs influencing plant shape, we analyzed six traits: plant height, tiller number, panicle diameter, panicle length, flag leaf length, and flag leaf width. We performed QTL analysis with 178 $F_7$ recombinant inbred lines (RILs) from a cross of japonica rice line 'SNU-SG1' and indica rice line 'Milyang23'. Using 131 molecular markers, including 28 insertion/deletion markers, we identified 11 main- and 16 minor-effect QTLs for the six traits with a threshold LOD value > 2.8. Our sequence analysis identified fifty-four candidate genes for the main-effect QTLs. By further comparison of coding sequences and meta-expression profiles between japonica and indica rice varieties, we finally chose 15 strong candidate genes for the 11 main-effect QTLs. Our study shows that the whole-genome sequence data substantially enhanced the efficiency of polymorphic marker development for QTL fine-mapping and the identification of possible candidate genes. This yields useful genetic resources for breeding high-yielding rice cultivars with improved plant architecture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.434-439
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• 2008

The amount of salt to make seed sorting solution of the specific gravity of 1.13 was reconsidered and determined as 3.8 kg salt in 18 L water, which is lower amount than currently used. Five rice cultivars were examined. Percent germination and seedling emergence were not similar. Seedling emergence rate of Japonica varieties, Nampyungbyeo and Daerypbyeo-1 were 87% and 95% under specific gravity of 1.13, respectively. Seedling emergence rate of Tongil type variety, Dasanbyeo was as high as 67% in specific gravity of 1.06. Seedling emergence rate of waxy rice, Hwasunchalbyeo and Aranghangchalbyeo were examined. Seedling emergence rate was 94% in both cultivars in specific gravity of 1.04. Seedling emergence rate was same in specific gravity of 1.08 which is generally used for selecting seed currently. Early growth (plant height, leaf number, and dry weight) were not significantly different by specific gravity within species. In all cultivars except waxy rice, highest seedling emergence rate was observed in specific gravity of 1.13 which is currently used for selection and decreased as specific gravity is lowed. However, considering total amount of seeds in each group of specific gravity, amount of seed in lower specific gravity group is relatively small and total seedling emergence rate within variety dose not show big difference. However, if seeds with low speicific gravity are produced due to the bad grain filling condition and consequently total seed content of low specific gravity increases, results will be differnt. Reduction in total growth and yield could occur. It will be important to comply with the seed sorting criterion of 1.13 for Japonica, 1.06 for Tongil, and 1.04 for waxy rice variety to ensure the maximum rice growth and yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.239-247
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• 1990

In order to investigate the degree of grain shedding of red rices collected in Korea, breaking tensile and breaking bending strengths of 269 varieties; 82 Korean and 100 foreign red rices and 87 Korean cultivars including 26 native varieties, 30 Japonica-Indica hybrids and 31 Japonica type varieties, were measured at harvest time. Also, histological characteristics of abscission region between spikelet and pedicel were observed. The breaking tensile and breaking bending strengths of both Korean and foreign red rices were weaker than those of Japonica-Indica hybrids which were known as easily shedding varieties in Korea. Abscission layers were observed in the majority of Korean red rices except for 5 varieties, and those of all varieties belonging to both long grain types and 'Sare's were cracked completely at harvest time, while those of round grain types were not cracked except one variety. The breaking tensile and breaking bending strengths of the tested varieties having cracked abscission layer were weaker than those of non-cracked ones. Both strengths of breaking tensile and breaking bending were positively correlated with diameter of supporting zone and thickness of sclerenchyma tissue surrounding central vascular tissue of suporting zone at 0.1% significant level, respectively.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.224-230
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• 1981

Threshing forces of seven varieties, that is, three Japonica type varieties-Irri 348, Irri 345, and Milyang 15, and four Indica type varieties-Milyang 23, Irri 342, Suweon 294 and Suweon 287-, which have been cultivated in the standard fertilization field being at Chungnam Provincial Office of Rural Development, Youseong, Chungnam-do, they were measured every other day in the period from September 28 to October 20 which were included the proper harves ting time. Also the threshing forces were checked in three-dimensional directions. Relationships between threshing forces and moisture contents of the unthreshed rice were examined in the laboratory as dried in the natural condition. The results of this study were as follows; 1. The mean threshing force of Japonica type varieties was about 1969r. and that of Indica type varieties was about 113gr. when external force was loaded in the direction parallel to the grain. 2. The threshing force bent to the grain was about 9.8through 28.2gr. equal to 7 through 21 percent to the threshing force parallel to the grain in Indica type varieties meanwhile about 59.8 through 115.0gr equal to 33 through 50 percent in Japonica type varieties. 3. Under the warmer temperature than $0^{\circ}C$, the change of threshing forces was not great in this experimental period on the harvesting dates. 4. The threshing force decreased s lightly as moisture content decreased in natural drying under the shade after cutting. 5. The threshing force of the lower portion was a little biger than that of the upper portion in an ear.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.85-90
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• 2005

This study was conducted to investigated the major characteristics of genetically modified rice of 'Milyang 204' originated from Dongjinbyeo compared to a non-transgenic rice varieties Dongjinbyeo and Jun-ambyeo. Basta resistant transgenic rice lines carrying bar gene produced by the Yeongnam Agricultural Research Institute were evaluated for their agronomic characters. The transgenic Japonica rice of 'Milyang 204' showed inferior phenotypic traits compared to a non-transgenic rice variety Dongjinbyeo and Junambyeo. On the basis of UPOV (Union Internationale Pour la Protaection des Obtentions Vegetables) and NSMO(National Seed Management Office) the transgenic 'Milyang 204' showed difference in some traits out of some agronomic traits, such as leaf color, angle of flag leaf, number of spikelets, culm length, white core and white belly compared to the non-transgenic varieties rice.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.206-241
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• 1985

Attempts to search infection period, infection speed in the tissue of neck blast of rice plant, location of inoculum source and effects of several conditions about the leaf sheath of rice plants for neck blast incidence have been made. 1. The most infectious period for neck blast incidence was the booting stage just before heading date, and most of necks have been infected during the booting stage and on heading date. But $Indica{\times}Japonica$ hybrid varieties had shown always high possibility for infection after booting stage. 2. Incubation period for neck blast of rice plants under natural conditions had rather a long period ranging from 10 to 22 days. Under artificial inoculation condition incubation period in the young panicle was shorter than in the old panicle. Panicles that emerged from the sheath of flag leaf had long incubation period, with a low infection rate and they also shown slow infection speed in the tissue. 3. Considering the incubation period of neck blast of rice plant, we assumed that the most effective application periods of chemicals are 5-10 days for immediate effective chemicals and 10-15 days for slow effective chemicals before heading. 4. Infiltration of conidia into the leaf sheath of rice plant carried out by saturation effect with water through the suture of the upper three leaves. The number of conidia observed in the leaf sheath during the booting stage were higher than those in the leaf sheath during other stages. Ligule had protected to infiltrate of conidia into the leaf sheath. 5. When conidia were infiltrated into the leaf sheath, the highest number of attached conidia was observed on the panicle base and panicle axis with hairs and degenerated panicle, which seemed to promote the infection of neck blast. 6. The lowest spore concentration for neck blast incidence was variable with rice varietal groups. $Indica{\times}Japonica$ hybrid varieties were infected easily compared to the Japonica type varieties, especially. The number of spores for neck blast incidence in $Indica{\times}Japonica$ hybrid varieties was less than 100 and disease index was higher also in $Indica{\times}Japonica$ hybrid than in Japonica type varieties. 7. Nitrogen content and silicate content were related with blast incidence in necks of rice plants in the different growing stage changed during growing period. Nitrogen content increased from booting stage to heading date and then decreased gradually as time passes. Silicate content increased from booting stage after heading with time. Change of these content promoted to increase neck blast infection. 8. Conidia moved to rice plant by ascending and desending dispersal and then attached on the rice plant. Conidia transfered horizontally was found very negligible. So we presumed that infection rate of neck blast was very low after emergence of panicle base from the leaf sheath. Also ascending air current by temperature difference between upper and lower side of rice plant seemed to increase the liberation of spores. 9. Conidial number of the blast fungus collected just before and after heading date was closely related with neck blast incidence. Lesions on three leaves from the top were closely related with neck blast incidence, because they had high potential for conidia formation of rice blast fungus and they were direct inoculum sources for neck blast. 10. The condition inside the leaf sheath was very favorable for the incidence of neck blast and the neck blast incidence in the leaf sheath increased as the level of fertilizer applied increased. Therefore, the infection rate of neck blast on the all panicle parts such as panicle base, panicle branches, spikelets, nodes, and internodes inside the leaf sheath didn't show differences due to varietal resistance or fertilizers applied. 11. Except for others among dominant species of fungi in the leaf sheath, only Gerlachia oryzae appeared to promote incidence of neck blast. It was assumed that days for heading of varieties were related with neck blast incidence.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.195-200
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• 1982

Fused phosphate and slag have used as a sources of phosphate and silicate fertilizers. In order to find out effects of these fertilizers on the growth of young rice plants in nursery, relationships between dry matter production and nutrient uptake at different fertilizer application rates were investigated for two rice varieties, Milyang 23 (a Indica-Japonica hybrid) and Akibare (a Japonica). The results were summarized as followers; 1. The maximum dry matter production was obtained at 75-150 kg/10a of fused phospate and 100-200 kg/10a of slag, respectively, however, a some variations between varieties were recognized. 2. The top/root ratio of varieties around 1.0 was proper for healty see dings and this ratio was reached at application of 75 kg/10a of fused phosphate and 200 kg/10a of slag. 3. The efficiency of applied silicate of rice seedlings was higher in fused phosphate than in slag. 4. The growth of seedling was severely retarded when soil pH was increased above 7 by the application of more than 225 kg/10a of fused phospahte and 400 kg/10a of slag.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.2
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• pp.83-92
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• 1976

The relationships between various nitrogen efficiencies among 57 rice cultivars grouped into three developmental categories were investigated by simple correlation with (12kg/10a) and without nitrogen fertilizer under the field condition. The relationship showed similar in a group or among all varieties of three groups. Yield among varieties showed highly significant correlation with Fe (fertilization efficiency: yield increment/nitrogen applied), E (nitrogen efficiency for yield), Ef(efficiency of nitrogen derived from fertilizer) and Eu (fertilizer use efficiency: nitrogen derived from fertilizer divided by total nitrogen applied). The E was correlated significantly and positively with harvest index (HI), percent translocation (T) of nitrogen to ear and negatively with nitrogen uptake amount (N), nitrogen concentration in grain (GN%) and in straw (SN%). The E depends almost on Ef and only inTongil group partly on Es (efficiency of nitrogen derived from soil). The Ef contributes to Fe more than Eu does (Fe = $Ef{\cdot}Eu$). It appears that Ef and Eu increased from the old group to the recommended local varieties, but only EF and Es increased markedly when rice was developed from recommended local group to Tongil line ($indica{\times}japonica$ hybrid selction). The fact that E and Fe depend more on Ef among rice varieties is very good contrast to the result that E and Fe depend more on Es and Eu respectively among soils in the previous investigatigation. The Ef appears as the most important parameter for rice varietal selection under fertilizer application system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.137-145
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• 1981

Using the milled, blast infected leaves (BIL) as an inoculum source on the screening for the resistance to blast of rice plant was a simple and useful technique. The temperature with high (25^\circ C\sim 35^\circ C) and low (15^\circ C\sim 28^\circ C) and the water stressed or not, was conditioned of to the inoculation with the BIL to the test varieties in seedling stage. In low temperature, most of the varieties were more infected with blast, however the Indica-Japonica hybrids were more infected in high temperature conditions. The water stressed was more infected with blast than the not stressed. The interaction of variety with water stress was not so much as that of variety with temperature. Resistant reaction to blast (BIL) was not affected by the temperature and water stress, but the moderately resistant or susceptible one was much affected by them. Inoculum of BIL was virulent to the newly bred Indica-Japonica hybrid cultivars such as Tongil, Nopung, etc, but not virulent to the Japonica cultivars such as Nongbaek, Jinheung, etc. The discrete, mixed or variable lesions were observed mainly in the moderately resistant or susceptible cultivars such as Kanto 51, Yashiromochi, Ishikari-shiroke, etc.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.232-232
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• 2017

Rice yields are determined by the number of spikes per unit area, the number of rice per grain, the rate of ripening, and the weight of brown rice gravel. Among these yield components, the most important factor that reflects the characteristics of rice is the number of rice per grain and the number of rice per grain. The characteristics of rice panicle are influenced by genetic factors rather than environmental factors and revealed that it had different genetic characteristics in each of Japonica, Indica and Japonica ${\times}$ Indica type. In general, the number of rice per grain is affected by number of secondary rachis branches and generated spikelets number of secondary rachis branches. This study conducted to investigate the characteristics of the grain according to the planting density of two varieties of Jap. ${\times}$ Ind. type. Number of primary rachis branches and number of primary rachis branches of Palbangmi variety were 9.9 ~ 10.6 and 53.4 ~ 58.5, respectively. Number of secondary rachis branches and number of secondary rachis branches were 25.8 ~ 29.6, 85.8 ~ 101.4, Number of tertiary rachis branch and number of tertiary rachis branches were 1.0 ~ 2.4 and 2.0 ~ 6.1, respectively. Number of primary rachis branches and number of primary rachis branches of Semimyeon variety were 8.6 ~ 9.5 and 43.1 ~ 47.8, respectively. Number of secondary rachis branches and number of secondary rachis branches were 21.0 ~ 24.9, 66.2 ~ 77.9, Number of tertiary rachis branch and number of tertiary rachis branches were 1.6 ~ 2.6 and 3.8 ~ 6.3, respectively. The ratio of the spikelets of primary, secondary and tertiary rachis branches of Palbangmi variety were 37.7 ~ 39.4, 58.0 ~ 60.5 and 1.2 ~ 3.1%, respectively, and those of Semimyeon were 40.1 ~ 42.6 55.0 ~ 56.4 and 2.5 ~ 3.4% respectively. Number of primary and secondary rachis branches of Palbangmi variety showed no difference among the planting density. However, generated spikelets number of secondary rachis branches and ripening rate were higher with lower planting density. The number of secondary rachis branches and generated spikelets number of secondary rachis branches per acre decreased as the planting density increased in the Semimyeon variety