• Magazine of the Korean Society of Agricultural Engineers
• /
• v.28 no.3
• /
• pp.79-88
• /
• 1986

Drought occurs most frequently and severely around transplanting season of the rice plants in Korea. Shortage of water due to drought for the paddy fields often delays transplanting, and less often the rice plants are subjected to water stress after delayed transplanting. The present study aimed at quantification of the rice crop loss due to delayed transplanting, different inten3ity of water stress, and the combined effect of delay in transplanting followed by water stress for better use of limited water for irrigation under drought. The rice variety Chucheong, a japonica, and Nampung, an indica x japonica, were grown, transplanted to 1/200 a plastic pots, and subjected to different timing of transplanting and degree of water stress under a rainfall autosersing, sliding clear plastic roof facility with completely randomized arrangement of 5 replications. The results obtained are summarized as follows: 1.Twelve days or 22 days delay in transplanting without water stress reduced rice yield by 25% and 43% in the japonica variety, and by 15% and 60% in the indica x japonica variety. 2.The 10 days or 20 days water stress developed without irrigation after drainage in the rice plants transplanted at proper time lowered the water potential at the paddy soil 10cm deep to -4 bar, and -12 bar and caused rice yield reduction by 14%, and 45% in the japonica variety and by 8%, and 50% in the indica X japonica variety. 3.The 12 days delay in transplanting and 10 days or 20 days water stress reduced rice yield by 39% and 59% in the japonica variety, and by 38% and 52% in the indica x japonica variety. The 22 days delay in transplanting plus 10 days water stress caused yield reduction by 76%, i.e. meaningless yield, in both varieties. 4.The intermittent irrigation just to wet the soil body for 10 days after 10 days water stress without irrigation increased rece yield by 12 to 16% compared to the rice plants water stessed without irrigation continuously for 20 days in both varieties respectively. 5.The above results suggest strongly 1) to transplant the rice plants at proper .time even with some water stress rather than delay for sufficient water from later rainfall, and 2) to distribute insufficient irrigation water to broader area of transplanted rice with limited irrigation for better use of limited irrigation water. A greater sensitivity of japonica variety to a moderate water stress than the indica X japonica variety during initial rooting and tillering stage was noticed. To cope with frequent drought in rice culture, firstly the lasting time of transplanting without yield reduction should be clarified by region and variety, and secondly a scheme of rational distribution of limited water should be developed by region with better knowledge on the varietal distribution of limited water should be developed by region with better knowledge on the varietal responses to varying intensity of water stress.

• Korean Journal of Food Science and Technology
• /
• v.28 no.2
• /
• pp.207-211
• /
• 1996

This study was carried out to determine the lipid content and neutral lipid compositions of Japonica and indica rice bran oils. The average content ratio of neutral lipids, g]ycolipids and phospholipids were 89.5 : 4.0 : 6.5 in japonica rice bran oil and 93.7 : 2.6 : 3.7 in Indica rice bran oils, respectively. It was seen that the neutral lipid content was significantly higher in JAponica rice bran oil, while the contents of glycolopods and phospholipids were significantly higher in japonica rice bran oils. The neutral lipids consisted of esterified sterol, triglyceride, free fatty acid, free sterol, diglyceride and monoglyceride. Triglyceride was the highest (48.7-49.7%) among the neutral lipids. Major fatty acids of rice bran oils were oleic (39.65-43.68f)), linoleic (32.62-39.42%) and palmitic acid (16.54-18.83%). The linoleic acid content was higher in Japonica rice bran oils than in indica rice bran oils.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.5
• /
• pp.870-876
• /
• 2001

Cordyceps is very famous of its board biological activities and vital function in traditional medicines. Fourdimensional response surface methodology was used for monitering of instant rice gruels. The organolepitc color of instant rice gruel prepared using mushroom and glutinuous rice showed the maximum score in 38.52% rate of glutinous rice 321.46 mL content of added water and 1.30 g content of P. japonica mycelia. The organoleptic taste of instant rice gruel prepared using mushroom and glutinous rice showed the maximum score in 64.86% rate of glutinous rice 270.66 mL content of added water and 2.32 g content of P. japonica mycelia. The organoleptic flavor of instant rice gruel prepared using mushroom and glutinous rice was maximized in 36.75% rate of glutinous rice, 323.40 mL content of added water and 1.42 g content of P. japonica mycelia. The organoleptic mouth-feel of instant rice gruel prepared using mushroom and glutinous rice was maximized in 65.33% rate of glutinous rice 275.37 mL content of added water and 2.41 g content of P. japonica mycelia. The organoleptic overall palatability of instant rice gruel prepared using mushroom and glutinous rice showed the maximum score in 40.94% rate of glutinous rice 352.79 mL content of added water and 1.27 g content of P. japonica mycelia.

• Korean journal of food and cookery science
• /
• v.2 no.2
• /
• pp.32-42
• /
• 1986

Two Tongil type rice varieties and two Japonica rice varieties were prepared and experimented to investigate the effect of physicochemical properties on rice palatibility. Obtained results are as follows; (1) Width and thickness of unhunlled and unpolished grains of Tongil type rices were shorter than those of Japonica type rices and the length of the former was much longer than the latter. (2) Protein contents of Tonsil type varieties were greater than Japonica ones and amylose contents of the former is less than the latter. Alkali digestibility of them showed no significant differences. These means that the qualities of Tongil rices are not less than Japonica ones. (3) Sensory evaluation test showed that Japonica type rices are more excellent than Tongil types in expansion, glutinosity, flavour and taste while the former is inferior to the letter in gloss. (4) Preconceived ideas on the shape of rice seemed to affect most on its palatability.

• Journal of Crop Science and Biotechnology
• /
• v.10 no.4
• /
• pp.265-276
• /
• 2007

The 13 major blast resistance(R) genes against Magnaporthe grisea were screened in a number of Korean rice varieties using molecular markers. Of the 98 rice varieties tested, 28 were found to contain the Pia gene originating from Japanese japonica rice genotypes. The Pib gene from BL1 and BL7 was incorporated into 39 Korean japonica varieties, whereas this same gene from the IRRI-bred indica varieties was detected in all Tongil-type varieties. We also found that 17 of the japonica varieties contained the Pii gene. The Pii gene in Korean rice varieties originates from the Korean japonica variety Nongbaeg, and Japanese japonica varieties Hitomebore, Inabawase, and Todorokiwase. The Pi5 gene, which clusters with Pii on chromosome 9, was identified only in Taebaeg. Thirty-four varieties were found to contain alleles of the resistance gene Pita or Pita-2. The Pita gene in japonica varieties was found to be inherited from the Japanese japonica genotype Shimokita, and the Pita-2 gene was from Fuji280 and Sadominori. Seventeen japonica and one Tongil-type varieties contained the Piz gene, which in the japonica varieties originates from Fukuhikari and 54BC-68. The Piz-t gene contained in three Tongil-type varieties was derived from IRRI-bred indica rice varieties. The Pi9(t) gene locus that is present in Korean japonica and Tongil-type varieties was not inherited from the original Pi9 gene from wild rice Oryza minuta. The Pik-multiple allele genes Pik, Pik-m, and Pik-p were identified in 24 of the varieties tested. In addition, the Pit gene inherited from the indica rice K59 strain was not found in any of the Korean japonica or Tongil-type varieties tested.

• YAKHAK HOEJI
• /
• v.58 no.3
• /
• pp.151-157
• /
• 2014

Water extracts of rice grasshopper (Oxya japonica japonica Thurnberg) were prepared and their antitumor and immunostimulatory activities were investigated using a flow cytometer. When LCT-CT was ip injected into ICR mice at the dose of 33.3 mg/kg before and after the implantation of $4{\times}10^5$ cells/mouse of sarcoma 180 tumor cells, it inhibited the growth of the tumor cells by 96.6%, showed lymphoblstogenic activities on the splenic lymphocytes and increased the expression of CD25 molecules on the splenic T lymphocytes. When co-cultured with the splenic lymphocytes of a BALB/c mouse, LCT-CT showed strong immunostimulatory activities at the concentration of $25{\sim}100{\mu}g/ml$ by significantly increasing lymphoblasts ratio and CD25 expression.

• Plant Resources
• /
• v.6 no.1
• /
• pp.16-26
• /
• 2003

Molecular markers are useful tools for evaluating genetic diversity and determining cultivar identity. Present study was conducted to evaluate the genetic diversity within a diverse collection of rice accessions used for Korean breeding programs. Two hundred eighty-seven rice cultivars, composed of temperate japonica, tropical japonica, indica, and Tongil-type of Korean crossing parents were evaluated by means of 15 simple sequence repeat (SSR) markers. A total of 99 alleles were detected, and the number of alleles per marker ranged from 4 to 11, with an average of 6.6 per locus. Polymorphism information content (PIC) for each of the SSR markers ranged from 0.2924 to 0.8102 with an average of 0.5785. These results, with the result that use of only 15 SSR markers made all rice cultivars examined could be uniquely distinguished, imply the efficiency of SSR markers for analysis of genetic diversity in rice. Cluster analysis was performed on similar coefficient matrics calculated from SSR markers to generate a dendogram in which two major groups corresponding to japonica (Group I) and indica and Tongil type rice (group II) with additional subclasses within both major groups. The narrowness of the Korean breeding germplasm was revealed by the fact that most of the Korean-bred and Japan-bred temperate japonica cultivars were concentrated into only 2 of the sub-group I-1 (143 cultivars) and I-2 (58 cultivars) among six sub-groups in major group of japonica. This is because of the japonica accessions used in this study was a very closely related ones because of frequent sharing of the crossing parents with similar genetic background with synergy effect of the inherited genetic difference between indica and japonica. A rice breeding strategy with the use of molecular markers was discussed for overcoming of genetic vulnerability owing to this genetic narrowness.

• Journal of Plant Biotechnology
• /
• v.40 no.2
• /
• pp.88-101
• /
• 2013

Eating quality of rice attracts more and more attention from rice-eating consumers in the recent years. Thus, improvement of eating quality of cooked rice has become one of the most important breeding goals in japonica rice. Here, the generation of transgenic japonica rice with improved eating quality and grain yield are reported. Overexpression of OsSbe1 gene encoding rice starch branching enzyme 1 was driven by 35S promoter. Eleven independent homozygous $T_3$ transgenic lines were characterized and had shown higher palatability (71.2 ~ 72.6) than wild type Gopum (70.4). Moreover, transgenic rice lines showed an increase in 1000-grain weight and number of spikelets per panicle compared with the wild type. The yield of milled rice was 562.8 ~ 596.7 kg/10a in eight $T_3$ lines, but 542.1 kg/10a in wild type. Gene expression analyses in mRNA transcription and enzyme activity levels suggest that improved eating quality is due to the up-regulation of OsSbe1 gene.

• Journal of the Korean Society of International Agriculture
• /
• v.31 no.3
• /
• pp.249-254
• /
• 2019

'Japonica 6' is a japonica rice variety developed from a cross between 'MS11', the beginning variety adaptable to tropical region, and 'IR86743-28-1-4', an elite line of high yield and good plant type by a Korea(RDA)-IRRI cooperative breeding program at IRRI in 2017. The growth duration of 'Japonica 6' is 121 days from sowing to harvest. It is 10 days later than that of the check variety 'MS11'. The culm length of 'Japonica 6' is 70 cm, and 1,000-brown rice grain weight is 26.7 g. It has a shorter culm and a larger grain. size than that of MS11. 'Japonica 6' is moderately resistant to blast disease but susceptible to bacterial blight, tungro virus and plant hoppers. The milled rice recovery rate of 'Japonica 6' is improved than that of 'MS11'. The head rice rate of 'Japonica 6' is significantly higher than that of 'MS11'. Yield of 'Japonica 6' is averagely 3.59 MT/ha of milled rice in 5 areas of the Philippines. The 'Japonica 6' was registered in Philippines and would be adaptable to the diverse regions of tropical Asia (Registration No in Philippines. BPI-NSIC-2017-Rc 484SR).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.30 no.3
• /
• pp.236-244
• /
• 1985

To know the varietal differences of ethylene evolution, 55 rice varieties were tested at seedling stage. And, also, 6 rice varieties were tested the biosynthesis of ethylene production. The group of japonica varieties produced higher amount of ethylene than the indica and indica x japonica crossed varieties. The content of ACC in rice seedlings of japonica varieties was higher than in seedlings of indica and indica x japonica varieties. And, also, the conversion rate of mathionine and ACC to ethylene in seedling of japonica varieties was higher than in seedling of indica and indica x japonica varieties.