• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.151-163
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• 1983

This study was conducted to investigate the responses to photoperiod of some Korean rice cultivars at four levels of the day length, 10, 12, 14 and 16 hours. Generally the days to heading were reduced in the short day length. Japonica varieties seemed to have shorter basic vegetative growth phase and, were more sensitive to day length, while Japonica crossed Indica varieties showed longer basic vegetative growth phase and, were less sensitive to day length. All tested varieties could be classified into 19 ecotypes based on the periods of the basic vegetative growth phase and the sensitivity to day length.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.391-402
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• 1986

A total of 16 varieties from Korea and Indonesia were tested in Suwon, Korea (126$^{\circ}$9'E, 37$^{\circ}$16'N, 37m amsl) and Bali, Indonesia (115$^{\circ}$ 14'E, 8$^{\circ}$42' and 10m amsl). Most varieties of Indica and India/Japonica types showed adaptability to both areas. Generally Indica-type showed more number of panicles per hill than that of Indica/Japonica, while Indica/Japonica showed better performance in spike let number per panicle and 1,000 grain weight than Indica-type varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.7-13
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• 1975

In other to determine the optimum condition for the alkali digestibility test, the milling degree of samples,the concentrations of potassium hydroxide,the temperature and the length of time for soaking were discussed.The results obtained from these experiment are summarized as follows; 1.Over 90 minute-milled samples in a new test tube miller showes the stable alkali digestibility values. 2.The optimum conditions for the alkali digestibility test were shown as 1.8 percent for the simultaneous treatment of Indica and Japonica varieties,1.4 percent or below for only Japonica and/or soft group varieties,and 2.2 percent of KOH for only Indoca and/ot hard group varieties provided the temperature and soaking time were fixed at \;30^{\circ} and 18 hours respectively.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.28-45
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• 2000

It was unusual crop weather for 1998 and 1999 compared with normal in Korea. The consecutive days of the optimum ripening period for rice plant that had daily mean temperature 21-23C for 40 days after heading, increased with long anomalies in 1998-99. The air temperature during ripening period was much higher than the optimum temperature and lower sunshine hour than normal in the local adaptability tests of newly developed rice lines during those years. In response of rice cultivation to warming and cloudy weather during crop season, the yield shall be decreased. Most scientists agree that the rate of heating is accelerating and temperature change could become increasingly disruptive. Weather patterns should also become more erratic. Agrometeorologists could be analyzed yearly variations of temperature, sunshine hour and rainfall pattern focused on transient agroclimate change for last a decade. Rice agronomists could be established taking advantage of real time agricultural meteorology information system for fertilization, irrigation, pest control and harvest. Also they could be analyzed the characteristics of flowering response of the recommended and newly bred rice cultivars for suitable cropping plan such as cultural patterns and sowing or transplanting date. Rice breeders should be deeply considered introducing the characteristics of basic vegetative type of flowering response like Tonsil rices as prospective rice cultivars corresponding to global warming because of the rices needed higher temperature at ripening stage than Japonica rices, photoperiod sensitive and thermo-sensitive ecotypes

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.785-794
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• 2013

To satisfy the consumer's interest with safety and high quality of staple foods, the physicochemical properties and cooking quality of organic rice using hairy vetch in Korea were compared. Two Korean varieties, Hopyeong and Ilmi, two Japanese varieties, Koshihikari and Hedomebore, and newly developed in Jeonnam, Mipum which cultivated in the same region and conditions were used. Physicochemical properties and cooking quality were investigated. All samples were japonica type short grains and their length/width ranged 1.74-1.84. The protein, ash, and crude lipid contents were significantly different with varieties and the protein content of Korean rice was lower than that of Japanese rice, especially, that of Hopyeong was the lowest. Amylose content and initial pasting temperature were lower in Hopyeong and Japanese rice, but peak viscosities showed reverse trends. Swelling power at $80^{\circ}C$ showed higher in Hopyeong and Koshihikari. Color values, L, a and b were significant difference with varieties and color differences of Hopyeong and Huitomebore were lower than those of others. Texture properties, hardness and adhesiveness of Hopyeong cooked rice showed the lowest values, but adhesiveness of Japanese cooked rice exhibited the highest value. On sensory evaluation of cooked rice, glossiness of Koshihikari, intactness of Koshihikari, Huitomebore, and Hopyeong, stickiness of Koshihikari and Hopyeong showed higher values (p<0.05). The overall quality score of organic cooked rices decreased as following order; Koshihikari> Hopyeong> Huitomebore> Mipum> Ilmi.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.618-623
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• 2006

This study was carried out to select the acceptance test influenced by some quality characteristics of rice, and may provide the basic information on rice grade of appearance quality as distinguished the numerical values. Forty-four Japonica rice varieties mainly cultivated in Korea were evaluated for a consumer acceptance test. Color preferences of rice were highly correlated with appearance quality (r=-0.897**) and redness (r=-0.893**). Especially, appearance quality value resulted from interaction of $redness{\times}yellowness$ values was expected as a specific character used for grade of rice appearance. Shape preferences of rice showed the positive correlation with grain width (r=0.527**) and grain size (r=0.454**). Result of the consumer acceptance test of rice appearance conducted through a cluster analysis revealed five groups. Our study suggests that it may be feasible to be graded by average of quality character among groups, grain width, and grain size in Duncan's multiple range test.

• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.169-175
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• 2005

This study was carried out to investigate the effects of irrigation water pollution on the yield and grain quality of rice. It acquires fundamental data to set up water quality standards for irrigation and produce agricultural safety products. The correlations of BOD, T-N, T-P, pH, ECw of the irrigation water with yield, grain appearance quality, and the protein content were evaluated. The field and pot experiments were conducted by using Japonica of Oryza sativa L. during 2 years. BOD concentration in irrigation water effects strongly on grain appearance quality and yield of rice. T-N in irrigation water has strong effect on the yield, appearance, and quality of rice. T-P concentration in irrigation water have not any correlation with yield and quality of rice. pH showed strongly negative correlation with maturity ratio(MTR), 1000 grain weight(TGW), and yield of rice(YLD) as r=-0.803~-0.828(p<0.001) and have no effect on the appearance quality of rice. $EC_w$ indicating salt content showed strongly negative correlation with MTR, TGW, number of grains per panicles(NGP), and number of panicles per unit area(NPM) as r=-0.759~-0.798, and with YLD as -0.753.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.206-211
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• 2014

Nutritional assessment of transgenic crops to improve safety evaluations is important for food production. An oxidative stress-tolerant rice was generated by stable insertion of the TC gene-a tocopherol cyclase isolated from tobacco-into the genome of a common variety of japonica colored rice. The nutritional composition of the brown rice grains from the transgenic TC line was compared with that of the parental rice cultivar Heugnambyeo and two different varieties of non-transgenic rice. The results indicate that the analyzed nutritional compositions of the brown grains from the transgenic TC line were within the range of values reported for other commercial lines, and measurements of nutritional compositions were equivalent to those of the non-transgenic rice.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.356-363
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• 2017

ARice is an important staple food in the world and rice yield is one of the main traits for rice breeding. Several genes involved in increasing the yield have been identified through map-based gene cloning within natural variations in rice. These identified genes are good targets for introducing a genetic trait in molecular breeding. Here, we chose five genes reported to be involved in increasing grain number per panicle in rice; Gn1a, dep1, Apo1, Ghd7, and Nal1. We developed In/Del markers for Gn1a, and dep1, Apo1, and applied the reported SNP markers for Ghd7 and Nal1. We were easily able to examine the genotype of each gene on agarose gel. We tested the genotypes on 479 rice resources that we held with evaluated molecular markers. According to the genotype of each gene, rice resources were divided into 13 haplotypes, and most of the Indica and Japonica varieties were included in haplotypes 1 and 13, respectively. When we examined the effect of each gene on grain number per panicle and panicle number per plant, panicle number per plant in the yield negative allele group for each gene was reduced by approximately 0.3 to 0.8 compared to that in the yield positive allele group. However, the number of yield positive alleles for each gene was higher by about 21 to 27 grains per panicle than that of yield negative alleles. Although most of the varieties were grouped in haplotypes 1 and 13, we believe that this genotype information with evaluated molecular markers will be useful in rice breeding for increasing the yield with grain number per panicle.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.527-533
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• 2006

The purpose of this study is to improve the culturability of a indica type rice cultivar, IR 36, using DNA marker associated with the ability of plant regeneration in anther and seed culture. The varietal difference of ability of callus formation and plant regeneration was investigated in anther and seed culture of 8 rice cultivars. Three japonica rice cultivars showed to have better culturability than those of tongil and indica type genotypes. But two indica/japonica lines, 'MGRI 079' and 'MGRI 036', which were selected to have good culturability in previous study showed the highest regenerability (20%) in anther culture of 8 rice cultivars. Thirty four $BC_2F_4$ lines were selected by marker screening using RZ400 for 100 $BC_2F_4$ lines derived from a cross $'MGRI\;079/IR\;36^{^*3}'$. The frequency of callus formation of 30 $BC_2F_4$ lines was higher than those of 'IR 36' in anther culture of the selected $BC_2F_4$ lines. The ability of plant regeneration of 15 lines was higher than that of 'IR 36' in the seed culture of 34 $BC_2F_4$ lines. A promising line, $BC_2F_4-28$, was selected to have better culturability in the anther and seed culture of the $BC_2F_4$ lines. The heading date and grain shape of the $BC_2F_4-28$ was similar to 'IR 36'. In seed culture of 50 $BC_4F_3$ lines derived from a rice cross $'MGRI\;079/IR\;36^{^*5}'$, 11 lines including $BC_4F_3-3$ showed to have higher regenerability compared with 'IR 36'. The highest frequency of plant regeneration (11%) was obtained from $BC_4F_3-46$ in seed culture of the $BC_4F_3$ lines.