• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.720-729
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• 1996

Effect of the cellulase treatment on the physicochemical properties of three varieties of rice (chucheongbyeo, chosengtongilbyeo and IR 36) and the texture of cooked rice were investigated. The swelling power and solubility of the rice flours were increased and amylographic viscosities, especially cold viscosities were decreased by cellulase treatment in all varieties. Gel chromatography of soluble carbohydrates from cellulase-treated rice flours on sepharose 2B-CL showed a singificant increase of low molecular weight $(10^{4})$ fraction which might be produced upon hydrolysis in endosperm cell wall constituents. The hardness of cooked rices prepared from cellulose-treated rices significantly decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.513-518
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• 2006

This study was conducted to investigate the relations between brown planthopper (BPH, Nilapavata lugens) resistance and specific organic acids (oxalic acid, silicic acid, and trans-aconitic acid) known as BPH sucking inhibitors on different rice varieties and/or lines. There were no specific relations between BPH resistance and the contents of oxalic and silicic acids in the rice plant tissues. However, the stronger the BPH resistance was occurred, the higher the content of trans-aconitic acid was contained in the rice plants. The relations between the injury rate of rice plant by BPH and the content of trans-aconitic acid in the rice plants were negatively correlated, which were -0.84 and -0.82 at 30 and 60 days after seeding, respectively. Therefore, the content of trans-aconitic acid in rice plant tissues might be utilized as an index for improving BPH resistance of rice varieties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.885-892
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• 2002

The purpose of this research was to prove the excellency of unpolished (brown) rice with respect to nutritional composition and to compare chemical composition among six varieties of rice. Some nutritional composition in the Polished (well -milled) rice and unpolished (brown) rice of the six typical Korean varieties (Chucheong, Hwasung, Odae, Ilmi, Dongjin, Ilpum) were determined. Most of nutrients in the brown rice were much greater than those in the milled rice and there was significant difference among rice varieties in some chemical compositions. The major minerals of milled rices were Ca, 6～15 mg%;P, 91～125mg%;Fe, 0.3～1.2mg%; Na, 10～14mg%;K, 106～205 mg%; Zn, 1.0～1.8mg%; and Mg, 32～58 mg%. The mineral contents of brown rices wre Ca, 4～11mg%;P, 92～286mg%;Fe, 1.3～1.9mg%;Na, 12～15mg%;K, 243～320mg%;Zn, 1.5～2.3mg%;Mg, 112～140mg%. Major fatty acids in six rice varieties were linoleic acid, oleic acid and palmitic acid, which comprised of about 93% of total fatty acid. Amino acid analysis showed that aspartic acid, glutamic acid, arginine and leucine were major amino acids, whereas histidine, threonine and tryptophan were minor ones of rice. Most ammo acid contents was higher in Ilmi than the other varieties. The contents of vitamin in brown rices were considerably higher than those in well-milled rice. There was not significant difference in total dietary fiber among rice varieties : 1.1～1.2% for milled rice,3.2～3.5% for brown rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.20-24
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• 1980

Seven different rice cultivars treated with different levels of gibberellic acid (0, 10, 50 and 100 PPM GA3) at panicle initiation stage. showed retardation effect on the panicle length and the 2nd internode from the top, where as, the total culm lengths were remarkably elongated, about 50-120% in short varieties and about 10-15% in the tall varieties over the control, mainly, because of the lower internodes elongation. The 2nd internode of Gamadi variety from Nepal was almost entirely shortened with GA3 application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.5
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• pp.413-417
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• 1993

This study was conducted to breed various cytoplasmic genetic male sterile (CGMS) and restorer lines with backgrounds of Korean japonica rice varieties. The CGMS line BT-CMS was crossed with the restorer line AR-3. The fertile $F_1 was emasculated and crossed with the Korean japonica rice varieties of the early maturing Sobaegbyeo, Odaebyeo, Gwanagbyeo and Daeseongbyeo, and of the medium maturing Hwajinbyeo, Paldal, Suwon 224 and Iri 386, and of the late maturing Nagdongbyeo, Palkweng, Hwacheongbyeo and Milyang 97. Each of the three way cross $F_{1S} was segregated into fertile and sterile individuals. The sterile individuals in each cross were discarded and the fertile individuals were emasculated and backcrossed with the Korean japonica rice varieties. The same process was applied from BC$_1$F$_1$ to BC$_4$F$_1$ generation. In the ${BC_4}{F_1}of each cross, the male sterile individual was crossed with the recurrent Korean japonica variety which was maintainer of male sterility. The male sterile lines of ${BC_6}{F_1}were named as Sobaegbyeo R, Odaebyeo R, Gwanagbyeo R, etc. The fertile individuals homozygous in pollen fertility were selected from the ${BC_4}{F_2}generation and named as Sobaegbyeo R, Odaebyeo R, Gwanagbyeo R, etc. Agronomic characteristics of the CGMS, restorer lines with backgrounds of Korean japonica, and the recurrent Korean japonica rice varieties grown in the field condition were compared. Culm length of the CGMS lines tended to be shorter than that of the recurrent parent, however no significant differences in heading date, panicle length and yield component were found among the CGMS, restorer and recurrent lines.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.727-734
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• 1996

Lipid composition was compared among rice varities such Dongjin, Jinmi and Tamjin as high, medium and low sensory quality, respectively Total and purified lipid contents of Jinmi were 1.7~2.2 times higher than those of Dongjin and Tamjin, and the lipid contents had not showed a tendency in the rice varieties with different sensory quality Dongjin of high sensory quality had high contents as 9.2~13.5% of neutral lipid and 3.1~4.7% of phospholipid, and low content as 12.3~18.2% of glycolipid compared with Jinmi and Tamjin of medium and low sensory quality. The rice varieties had not showed a tendency as a difference of sensory quality in compositions of neutral and phospholipid. As the sensory quality increased in the rice varieties, monogalactosyl diglycerides, steryl glycosides had high contents as 0.4~19.24% and 14.4~17.1%, and esterified steryl glycosides, celebrosides and digalactosyl diglycerides had low contents 15.3~28.1%, 1.2~5.7% and 2.8~3.8%, respectively, in glycolipid. Fatty acid composition also had no tendency as a difference of sensory quality of the rice varities in compositions of neutral and phospholipid. Palmitic acid, however, had a high content as 0.4~22.6% and linoleic acid had a low content as 5.0~12.0% in fatty acid composition of glycolipid.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.766-771
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• 1989

physicochemical properties of rice starch isolated from eight varieties were examined to evaluate the rice processing suitability The amylose contents of rice starch were varied with 16.7-29.7%, and IR 30, Godael, Aguja and Lengkwang varieties showed higher amylose content than the other varieties. The water binding capacity and blue value were in the range of 87.0 103.0 and 0.178-0.305, respectively. As the amylose content increased, the amylogram pasting temperature and the break down ratio increased, while the peak viscosity did not show any significant difference. The transmittance of 0.1% starch suspension slowly increased at $50^{\circ}C$ in the low-amylose content rice group, and rapidly increased at $65^{\circ}C$ in the high-amylose content rice group, but there were no differences above $75^{\circ}C$ among varieties. Also the low-amylose rice starch showed higher values in the swelling power and solubility. The hardness of the 30% rice starch gels was low in low-amylose one. During storage at $20^{\circ}C$ for 14 days, the increment of hardness was more slow in high-amylose one. The retrogradation velocity constant of rice starch gel by Avrami equation was the highest as 0.219 in Aguja variety.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.306-306
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• 2017

Screening for drought and salinity tolerance was undertaken for selected Philippine upland rice landraces during germinative and seedling stages to identify varieties which can potentially be grown in marginally dry and saline soils. While increasing PEG and NaCl concentrations caused obvious signs of injury to all rice genotypes, considerable varietal differences were noted in the nature of responses providing evidence that these genotypes possess broad intraspecific genetic variations for drought and salt tolerance. Inconsistent responses of these varieties during both growth stages highlight complexities involved in stress responses and underscore the futility of utilizing a single stage in the rice plant's life cycle for physiological screening. Notwithstanding these perplexing responses, G_Katiil and Ml-Pilit Tapul were observed to thrive relatively well despite increased salt and drought stress during early growth stages and may therefore possess genes needed in crop improvement efforts for drought and salinity tolerance. While these results do not reflect the entire spectrum of adaptive expression to drought and salinity stress during the life cycle of the upland rice plant, they nonetheless provide an easy, reliable and reproducible method for preliminary identification of drought and salt tolerant rice varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.343-349
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• 1993

This study was conducted 1)to determine the factors responsible for the gradually increased rice yield by examining any improvements in yield-related characters and physiological characters among the historically recommended varieties of rice in Korea, and 2)to reveal the way of achieving further yield improvement by breeding in the future. Eight recommended varieties from 1911 to 1988 were selected and grown at the same conditions. The yield-related characters were observed at the harvest time, and the physiological characters such as RGR, NAR, LAR, SLA and L WR were estimated by the classical method of growth analysis. The newer varieties are shorter and those released after 1970's are greater in percent of filled spikelets and harvest index than the older varieties. There are no definite changing trends in the variations of number of panicles per hill, number of spikelets per panicle and 1000 grain weight according to the course of evolution in the recommended varieties. There is little evidence of improvement in the physiological characters such as NAR, LAR, SLA and LWR among the recently developed varieties compared with those of the older varieties. The increase in grain yield due to variety improvement, if any, is largely associated with the greater harvest index and percent of filled spikelets by breeding blight resistant and / or lodging resistant genotypes with short culm. It is suggested that increase in NAR should be carried out simultaneously with increase in harvest index to breed high yielding genotypes. I t appears to be important to breed genotypes with long culm in order to enhance light penetration into the canopy as long as they are lodging resistant. Since NAR is negatively correlated with LAR, it is unlikely to succeed to improve both characters simultaneously. The direct effect of NAR on RGR by path analysis is much larger than that of LAR, and hence it is suggested that breeding genotype with large NAR is more effective on enhancing RGR. It is also suggested that improving LAR through LWR is likely effective on increasing RGR.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.222-233
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• 2022

The heading responses of rice varieties that originated from South Korea, North Korea, and northern China were examined under the temperature and day-length conditions of 13 major rice production areas in North Korea. Kenjiandao3 and Nongdae3 originated from China, Olbyeo1, Olbyeo2 and Sonbong9 from North Korea, and Joun from South Korea demonstrated the earliest heading stage depending on the regional environment. Out of 40 rice varieties, 34 reached the heading stage within the regional safe marginal heading date (SMHD) under Haeju and Sariwon environmental conditions, while 16 to 17 varieties reached the heading stage under Wonsan, Changjon, Supung, and Yongyon environmental conditions. Some middle and mid-late maturing varieties that originated from South Korea reached the heading stage within the SMHD under the temperature and day-length conditions of Kaesong, Haeju, Sariwon, Nampo, and Pyongyang that are located in the west-southern plain. The majority of early maturing varieties, but not the middle or mid-late ones, reached the heading stage within the SMHD under the environmental conditions of Singye, Anju, Kusong, and Sinuiju. Only a few early maturing varieties demonstrated the heading stage within the SMHD under Yongyon, Changjon, and Wonsan environments. The number of days to heading was highly positively correlated among all regions; however, it was not consistent among the rice varieties. The 40 rice varieties that had been tested were classified into seven groups according to their heading responses to the temperature and day-length variations of the 13 regional conditions at 65% similarity level in cluster analysis.