• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.69-76
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• 1987

The aerobic heterotrophic bacteria in the histosphere associated with grasses (Gramineae, Caryphyllaceae, Crucifereae) and rice cultivars in saline and reclaimed saline paddy soils were varied with species and rice cultivars. The fraction of aerobic heterotrophic $N_2$-fixing bacteria to the total aerobic heterotrophic bacteria were averaged to eighteen percent in the histosphere of grasses and rice. Acetylene reducing activity of these bacteria were ranged from 1 to 24 n mole/tube/hr. Most of the bacteria strains were predominated of hydrogen utilizing bacteria. The majority of these bacteria were closed to Pseudomonas, Azospirillum, Klebsiella and Agrobacter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.182-188
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• 1997

The study was carried out to determine an optimum concentration of plant growth regulators(ABA and kinetin) on reducing NaCl toxicity during germination in rice. Plant height of a japonica cultivar Ilpumbyeo in ABA 10$^{-5}$ M was increased, while all treatments of kinetin had no clear effects on increasing the plant height. However, other rice cultivars showed slightly different reaction by PGRs compared with Ilpumbyeo. Germination rate of four rice cultivars was ranged from 53.1 to 58.2％ in NaCl 1.3％. All treatments of kinetin accelerated germination rate of tested rice cultivars except Dasanbyeo compared with NaCl 1.3％ treatment. The higher concentration of ABA and kinetin treatment induced the higher starch content, and while the lower concentration of two plant growth regulators induced the higher sugar content in all four rice cultivars. The free proline content of rice seedlings was highest in Ilpumbyeo among the tested cultivars under NaCl 1.3％ treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.127-133
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• 1989

An experiment was conducted at the Yeongnam Crop Experiment Station to obtain basic informations about cultural techniques for high yield by manipulating plant spacing in association with seedling number. Cultivars showing relatively low competition index within or between rice hill were Palgongbyeo, Milyang 83. Milyang 90 and Sangpungbyeo, while those with high competition index were Pungsanbyeo, Samgangbyeo, Weongpungbyeo, Taebaegbyeo and Dongjinbyeo. Variations of agronomic characters such as culm length, spikelets per panicle, grain yield per panicle among each culm within hill were not interrelated among the characters. This phenomenon was also same within and between cultivar groups. However, cultivars having high competitive ability showed relatively low variation in agronomic characters. There was a trend that most of rice cultivars had a high positive correlation between total competition index and rice grain yield. Competition index between rice hill was more significant than that of within rice hill for Tongil type cultivars except Milyang 83 which belonged to low tillering capacity while both types of competition index within and between hill were important for Japonica type cultivars and Milyang 83 of Tongil type cultivar to increase rice yield.

• Korean Journal Plant Pathology
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• v.3 no.2
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• pp.93-99
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• 1987

Six rice cultivars showing various types of resistance or susceptibility to Pyricularia oryzae in the field were used to study the relationship between susceptibility and contents of carbohydrates, amino acids and phenolics at different plant maturities and leaf ages under controlled environmental conditions. No consistent differences between the susceptible cultivars and adult-plant-resistant cultivars were found in terms of the contents of individual carbohydrates, total amino acids and phenolics in rice leaves throughout the plant development. Only the adult-plant-resistant cultivar Dobong had lower contents of inositol throughout the plant development than the other cultivars. The amounts of sucrose, inositol, glucose, and fructose increased in all tested cultivars at eight leaf stage than those at five leaf stage, but slightly decreased at twelve leaf stage. In contrast, total amino acids and phenolics gradually decreased during plant development. With increasing age of rice leaves, the amounts of total soluble amino acids and phenolics gradually increased in healthy fifth leaf tissues, although there were no significant differences between the cultivars. In particular, a high level of phenolics existed in old fifth leaves of the cultivar Dobong. These results suggest that increased resistance to blast of matured rice plants and old leaves may be the two different phenomina derived from the physiological changes occurring during plant development and leaf senescence, probably functioning differently in P. oryzae development.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.1-5
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• 1997

The purpose of this study was to determine the inheritance of chlorosis under low temperature at seedling stage of rice. The expression of chlorosis among 21 rice cultivars treated at $18^{\circ}C$ showed in one Tongil type cultivar, Milyang 23, and two Indica type cultivars, IR 36 and Dular. The sign of chlorosis was not appeared in all of the japonica type cultivars under the same treatment. The reduction of chlorophyll content under the low temperature was differed from varietal group and cultivars. The $F_2$ population from a cross between Toyohatamochi and Dular segregated 3:1 ratio for normal and white phenotypes of third leaf. From the result, it was suggested that the chlorosis was controlled by a single recessive gene. The chlorosis rice detected from this study will be used as a good material for the genetic study related to photosynthetic ability of rice.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.132-139
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• 1996

Acetolactate synthase(ALS) activity was determined in germinating seedlings of two rice cultivars treated with cinosulfuron [3-(4,6-dimethoxy-1,3,5-triazin-2-yl)-1-[2-methoxyethoxy)-phenylsulfonyl]-urea]. IR 74(Indica type) was more tolerant than Hwajinbyeo(Japonica type) under various rates of cinosulfuron applied at the pregermination stage. In vitro response of ALS activity in the two rice cultivars was similar to $I_{50}$ values(cinosulfuron concentration required for 50% inhibition of ALS activity) of about 23ppb. In vivo, ALS activity of IR 74 increased as the seedlings grew, but that of Hwajinbyeo dropped at 5 days after 10ppm cinosulfuron treatment and shoot growth of Hwajinbyeo lagged at 4 to 5 days after herbicide treatment. ALS activity and shoot growth of Hwajinbyeo was resumed from cinosulfuron-induced inhibition at 6 days after cinosulfuron treatment. The differential response of ALS activity in two different rice cultivars against cinosulfuron may not be due to difference of ALS sensitivity, but rather due to different metabolic inactivation rates of cinosulfuron.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.179-183
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• 1998

The cyanidin 3-glucoside (C3G) extracted from pigmented rice seeds in 0.5% TFA (Trifluoro acetic acid) -95% ethanol was separated by High Performance Liquid Chromatography (HPLC). A HPLC system using a Develosil ODS-5 column and 0.1 % TFA-$H_2O$～0.1 % TFA-$CH_3CN$ gradient elution was selected for separation and quantitative determination of C3G. Regression equation obtained for the standard content of C3G pigment was as Y=21.95293$^*$X-14.726771 (r=0.99$^{**}$). Using this method, 326 domestic and introduced collections were evaluated for the C3G content. The Korean bred cultivar 'Heugjinjubyeo', showed highest C3G content (552 mg/100g seed) among the tested cultivars. Among the pigmented rice cultivars ten cultivars were selected for containing a high content of C3G. The content of C3G per 100g seeds was in high order as follows: Heugjinjubyeo (552mg)>Cheng Chang (321mg)>Kilimgeugmi (240mg)>PI160979-2 (224mg)>Hong Shei Lo (221mg)>Heugnambyeo (191 mg)>Mitak =PIl60979-1 (186mg)>Suwon425 (163mg)>Sanghaehyanghyeolla (108mg). The C3G pigment was not detected in the common white rice cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.45-50
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• 2007

This study was investigated the relationship between palatability and physicochemical properties of rice kernels from two rice cultivars, including Gopumbyeo and Palgongbyeo. Major fatty acids of rice were oleic(35% in Gopum, 33.2% in Palgong, respectively) and linoleic acids (42.9% in Gopumbyeo, 40.7% in Palgongbyeo, respectively). There were significant differences in composition of amino acids and content of sugar from non-starch polysaccharide between two rice cultivars. However, no difference was found in mineral contents between Gopumbyeo and Palgongbyeo. In Rapid Visco Analyzer examination, pasting temperature and breakdown of Gopumbyeo were lower than those of Plagongbyeo. In X-ray diffraction patterns of starches separated from two rice cultivars, traditional A type and there was no difference in crystalline of rice starch. We could also obtain the results that Goupumbyeo, known to have good eating quality, had higher palatability value than Palgongbyeo.

• The Korean Journal of Food And Nutrition
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• v.32 no.5
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• pp.571-579
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• 2019

For the purpose of promoting the consumption of rice powder, 5 cultivars were applied differently to establish the optimal manufacturing conditions and measured Hunter color values, hardness and expansion rate of Yakgwa for the optimal conditions. Looking into the optimal manufacturing conditions of Yakgwa, the commercial flour-facilitating Yakgwa is shown to have a great shape when the mold is made with a thick paste for C-2 manufacturing method, Hangaru 100 mesh for H100-2 manufacturing method, Hangaru 200 mesh for H200-2 manufacturing method, Shingil 100 mesh for S100-2 manufacturing method, and Shingil 200 mesh for S200-1 manufacturing method. It also showed a trend of chewy taste after frying without cracks. Hunter color values (L) and red chromaticity and value b of yellow chromaticity indicated a lower value for the commercial flour and Hangaru 200 mesh in its entirety. The hardness of Yakgwa is within the range of 1,981.41~3,756.45 g and the degree of hardness is shown differently for each rice powder exclusive cultivars. Rice flour developed as rice powder 5 cultivars, and as a result of measuring chromaticity, hardness and expansion rate of Yakgwa for the quality characteristics, the item of hangaru 200 mesh had outstanding quality characteristics for Yakgwa.

• Korean Journal of Agricultural Science
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• v.39 no.1
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• pp.9-15
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• 2012

The study was conducted to evaluate the genetic similarity among commercial japonica rice varieties in Korea and China and to develop markers to differentiate between japonica cultivars developed in Korea and China. The genetic similarity and cluster of 38 accessions were analyzed using 47 SSR(simple sequence repeat) markers. The number of alleles by 47 SSR markers ranged from 2 to 9 with an average of 3.6. A total of 169 alleles were detected among these tested rice varieties. The PIC value varied from 0.05 to 0.79 with an average of 0.44. The Chinese japonica cultivars could be differentiated from the japonica cultivars in Korea by combining 2 SSR markers, RM223 and RM266. Cluster analysis showed that 38 tested varieties could be distinguished into japonica and indica based on the genetic distance.