• Journal of Agricultural Extension & Community Development
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• v.10 no.1
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• pp.103-114
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• 2003

The purpose of this study is to examine Japonica rice farming of China. Asian rice is divided into Japonica and Indica species. Japonica rice represents only less than 20% of Chinese rice output, but it can compete with Korea rice in both price and quality. The rise of income level has expanded the scale of production of Japonica rice in China. China’s adhesion to the World Trade Organization (WTO) has forced Chinese policy makers to face their obligations and responsibilities such as abolishing subsidies on agricultural exports. But being member of the WTO entry also helps China exercise and enhance its influential place in the global economy. Because of geographical proximity and the fact that Korea is ranked second among countries with which China still has a trade deficit, China may seek and plead for an opening of the protected Korean rice market to stabilize prices and prevent excess supply of Chinese rice. Though Korean rice farmers feel that prices are still low, Chinese rice remains far cheaper than Korean rice with the price gap is still on the rise. In anticipation of such fierce competition, Korea must carefully review its current policies and closely follow the evolution of rice production, marketing, and trade in China. This study also suggests some of the possible research using more recent data that should be conducted in the future.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.613-618
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• 1989

Tirteen rice varieties of Japonica-Indica briefing type (J-I breeding type) and ten of Japonica type produced in Korea in 1985 were studied on cooking quality of milled rice and texture of cooked rice. The results are as follows: in the Looking quality, water uptake ratio of cooked rice and total solid in residual liquid showed significant $(p<2.172^*\;and\;2.419^*,\;respectively)$ between J-I breeding type and Japonica type The water uptake ratio of cooked rice was higher J-I breeding type than Japonica type but the total solid and intensity of iodine blue value in residual liquid were lower J-I breeding type than Japonica type. Minimum cooking time of milled rice showed significant $(p<2.375^*)$ between J-I breeding type and Japonica type for texture of cooked rice. The cooking time of J-I breeding type shorter than Japonica type. Hardness and cohesiveness in texture of cooked rice appeared to be significant cant $(p<4.370^{***}\;and\;2.371^*,\;respectively)$ between J-I breeding type and Japonica type, and then hardness was higher Japonica type than J-I breeding type, but cohesiveness was lower Japonica type than J-I breeding type. The correlation coefficients between amylose content and adhesiveness of varieties in the same type was $-0.922^{**}$ in J-I breeding type and $-0.915^**}$ in Japonica type. The correlation coefficients between protein content and hardness of the varieties in the same type was $0.954^{**}$ in Japonica type and so denoted as positive correlation. And the scatter diagram between protein and hardness could be divided into J-I breeding type and Japonica type.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.384-389
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• 1989

Thirteen varieties of Tongil type and ten of Japonica type which were produced in Korea, in 1985, were campa red in namely, width, thickness, length and weight of rice grains. Thousand-grain weight of paddy, brown rice and milled rice were not significantly different between Tongil type and Japonica type, but difference of paddy-brown rice and brown rice-milled rice had significant (p<2,859** and 4.316***, respectively), and the ratio of difference of paddy-brown rice was higher Tongil type than Japonica type. Width, thickness and length of paddy, brown rice and milled rice was significant (width : p<5.189***, 5.289** and 5.466***, thickness: p<3.371** 4.074*** and 5.988***, length: p<3.016**, 4.419*** and 5.492*** in paddy, brown rice and milled rice, respectively) between the Tongil type and Japonica type, and then the width and thickness of Japonica type were thicker than Tongil type, but length of Japonica type was shorter than Tongil type width/thickness ratio of paddy wes significant (p<2.396*) between the Tongil type and Japonica type, but its brown rice and milled rice was not. And length/width and length/ thickness ratio of paddy, brown rice and milled rice were significant (length/width : p<5.525***, 5.495*** and 5.863***, length/thickness: p<4.734***, 6,863*** and 8.425*** in paddy, brown rice and milled rice) between the Tongil type and Japonica type, and then its ratio were higher Tongil type than Japonica type.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.684-689
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• 1995

The molecular structure of rice starch was investigated using Korean rice[3 varieties of Japonica type and 3 varieties of Tongi type(Japonica-Indica breeding type)]. The λmax of iodine complex and inherent viscosity of Japonica type were higher than those of Tongil type. $\beta$-Amylolysis limit of the starches was not different between the two rice types. In the distribution of molecular weight of rice starch, the molecular size of amylose and amylopectin for Japonica type were smaller than those for Tongil type. The chain of rice starch distributed F1 of above DP 55, F2 of DP 40~50 and F3 of DP 15~20, and the ratio of F3 against F2 for Japonica type was higher than that of Tongil type. The results suggest that rice of Japonica and Tongil type was different molecular structure of starch.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.97-101
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• 1988

The objective of this paper was to examine the oxygen requriement of rice seeds when the seeds were germinating under the water. The trial was carried out in the laboratory with the different water temperature (25$^{\circ}C$, 17$^{\circ}C$) in the Crop Experiment Station, Suwon. The tested varieties were 6 in japonica and 6 in indica (I) ${\times}$ japonica (J). In the 25$^{\circ}C$ water temperature rice seeds absorbed more dissolved oxygen (DO) and germinating duration was shorter than in the 17$^{\circ}C$ water temperature. DO uptake of japonica rice seeds was faster than that of indica ${\times}$ japonica rice seeds, and the germinating ratio of japonica rice seeds was higher than that of I${\times}$J rice seeds in the water. DO requirements of germinating rice seeds in the water were average 82.4 ${\mu}$g per seed up to coleoptile appearance and average 123.6 ${\mu}$g per seed up to appearance of radicle in the japonica varieties, but I${\times}$J varieties were 96.9 ${\mu}$g and 145.1 ${\mu}$g respectively. Especially when the rice seeds were germinated in the water, length of coleoptile and radicle of japonica rice were significantly longer than those of I${\times}$J rice varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.233-238
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• 1990

Weedy rice(red rice) collected in Korea were crossed with the Japonica, Javanica and Indica tester cultivars, and also crossed among those collected lines. Their seed fertility was counted and refered to their cross affinities. Some tester cultivars such as, Suweongjo, Malagkit Sinaguing and wx 817 which were regarded as belong to the Japonica, Javanica and Indica respectively, showed the typical tendencies of hybrid sterility when they were crossed each other. But, other testers such as Kwanak, Tapaiko, Belle Patna and Tarichaosun showed some differencies from those typical patterns, implying some varigations within a ecotype. The hybrids of weedy rice crossed to the Japonica testers showed higher fertility with a few semisterilities. While the crosses of weedy rice to the Javanicas or Indicas showed high sterility implying closer affinity relationships of weedy rice to the Japonicas. Even those weedy rice lines such as Samsanmyeon 8 and Sanchungaengmi B which showed semi-sterility when they were crossed to the Japonica testers showed high sterility when they were crossed to both Javanicas and Indicas. The hybrids among weedy rice lines showed high fertility raning 69% to 96%. Even those weedy rice lines which showed semi-sterility in the crosses with Japonica testers, showed high-fertility when they were crossed with those weedy rice lines. Though the amylose content, Alkali Digestive Value, Phenol reaction and grain shapes of theose weedy rice lines showed divers variations, the cross affinities of them showed closer phylogenie relationship to the Japonicas than to Japvanicas or Indicas. But the genetic influinces of Indicas to those weedy rices were not ignorable.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.292-292
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• 2022

Since 1992, the Rural Development Administration (RDA), Republic of Korea in collaboration with International Rice Research Institute (IRRI) has developed 6 japonica rice varieties(MS11, Japonica 1, 2, 6, 7 and Cordillera 4) that are adaptable to tropical regions. However, these varieties show moderate resistance or susceptibility to certain biotic and abiotic stress. The development of varieties with more stable forms of resistance is highly desirable, and this could be possibly achieved through rapid introgression of known biotic and abiotic resistant genes. In this study, we analyzed the allele types of major biotic stress resistant genes including Xa5, Xa13, Xa21 and Xa25 for bacterial leaf blight, Pi5, Pi40, Pish and Pita2 for blast, tsv1 for rice tungro spherical virus, and Bph6, Bph9, Bph17, Bph18 and Bph32 for brown planthopper by using gene-specific molecular markers. In addition, seed quality related genes Sdr4 for preharvest sprouting and qLG-9 for seed longevity were also analyzed. The results revealed that2h5 and Xa25 resistance alleles showed in all varieties while Pi5 resistance allele showed only in MS11. The Pish resistance allele were present in five varieties except for Japonica 1. Meanwhile, for the rest of the genes, no presence of resistance alleles found in six varieties. In conclusions, most of tropical japonica varieties are lack of the major biotic stress resistant genes and seed quality genes (Sdr4 and qLG-9). Moreover, the results indicated that rapid deployment of a few major genes in the current tropical japonica rice varieties is urgent to increase durability and spectrum of biotic stress resistance and also seed dormancy/longevity which are essential traits for tropical environments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.735-740
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• 1996

This study was carried out to determine the composition of glycolipids and phospholipids in Japonica and Indica rice bran oils. The ratio of glycolipids and phospholipids was 4.1 : 6.5% in Japonica rice bran oils and 2.6 : 3.7% in Indica rice bran oils. Polar lipid content was significantly higher in Japonica rice bran oils. The main components of glycolipids were esterified steryl glycoside, monogalactosyl diglyceride steryl glycoside, cerebroside and digalactosyl diglyceride. The content of esterified steryl glycoside was the highest, resulting in 48.8~52.1% of total glycolipids. Phospholipids in rice bran oils consisted of diphosphatidyl glycerol, phosphatidyl ethanolamines, phosphatidyl inositol, phosphatidyl serines, phosphatidyl choline and lysophosphotidyl choline. Major fatty acids of the glycolipids and phospholipids fractions were oleic, linoleic and palmitic acids in Japonica and Indica rice bran oils.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.207-213
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• 1999

Thirty-eight glutinous rice varieties were classified into nine groups on the scatter diagram by the upper two principal components (56% contribution to the total information) based on eleven physicochemical characteristics including the viscograms and physical properties of cooked rice. The first principal component was the factor mainly associated with the viscogram characteristics of rice flour emulsion and the second was the factor chiefly related to the physical properties of cooked rice and water absorbability of rice grain. Indica glutinous rices were clearly distinguished from japonica ones by the first principal component score. Javanica glutinous rices were widely distributed on the intermediate zone between indica and japonica or on several japonica rice groups. Significant positive or negative correlations were found among water absorption rates of rice grain, physical properties of cooked rice, and viscogram characteristics of rice flour. Especially in japonica glutinous rices, the breakdown and setback viscosities of rice flour were closely associated with the alkali digestion value of milled rice and the stickiness of cooked rice. The frequency ratio of short glucose chains (A-chain) to intermediate glucose chains (B-chain), the ratio of B- chains to long glucose chains (C-chain) and the relative frequency of A- or B-chain fractions representing the amylopection structure of rice starch was closely associated with the breakdown and setback viscosities of rice flour.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.735-743
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• 2011

This study examined physicochemical properties of rice grains and qualities of cooked white rice of the high yielding, Japonica type, specifically Druryechanbyeo and Boramchanbyeo, and of the Tongil-type, specifically Hanarumbyeo and Andabyeo. The changes of water absorption rate of rice grains, their textural properties and a sensory evaluation of the cooked rice s were analyzed. All varieties were short grain. The length and width of Tongil type rice grains larger than those of Japonica type. The water absorption of white rice grains increased rapidly until 1 hr when soaking and after that increased slightly. The water absorption of Druryechan grain was higher than that of the Boramchan. The sensory evaluation results showed that the Japonica type cooked rices had a higher value for overall quality than the Tongil type cooked rices. With regard to the textural properties of the cooked rices, the hardness of Boramchan and Hanarum varieties showed higher than that of Druyechan and Anda varieties. Adhesiveness, springiness and chewiness were not significantly different between varieties (p<0.05).