• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.277-282
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• 1983

Number and percentage of diseased area of leaf blast lesions formed on different leaf location were mostly distributed from the flag leaf(n-1) to the 3rd leaf from the top(n-3) in Tongil line rice varieties and on the 2nd leaf from the top(n-2) in Japonica type rice varieties. Especially leaf lesions of Nopung which was more susceptible to leaf blast among Ton1 line rice varieties were mostly distributed on flag leaf. Relation between the degree of lesion distribution and level of fertilizer was more clear with an increase of fertilizer quantity. Leaf blast lesions of rice varieties were generally distributed from the flag leaf to the with leaf from the top but mainly those at flag leaf and the 2nd leaf from the top were found to be most responsible for inoculum source of panicle blast after booting stage. Increase of the conidia formation was resulted from fluctuation of temperature$(24^{\circ}C\~16^{\circ}C)$ in low temperature range after booting stage and many inoculum sources were supplied on panicles until the end of September without impeding dispersal from leaf blast lesions as an inoculum source of panicle blast.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.199-214
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• 1977

These studies were conducted to obtain basic information of the rice blast resistance in comparision with blast occurrence patterns in the blast nursery test in Korea. One hupdred and twenty nine rice varieties including several blast differential varieties and 30 combinations of pedigree lines were tested at six different locations, Suweon, Chulweon, Chuncheon, Iri, Jinan, Imsil, and Milyang, in 1976~1977. The results obtained are summarized as follows: 1. When blast resistance was tested using three sets of differential varieties at six locations, prevalent races were different depending on the location and differential variety set tested. 2. There were regional differences in blast disease reation among Japonica rice varieties and among Indica${\times}$Japonica crosses. 3. At Suweon blast disease reactions of pedigree lines were different from that at Imsil. 4. Three varietal groups were made depending on the develpment of rice blast in the nursery test. 5. In general, highly resistant varieties to rice leaf blast were also resistant to neck blast, but there were exceptions.

• Korean journal of applied entomology
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• v.41 no.2
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• pp.113-121
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• 2002

This study investigated the changes in the fitness of brown planthopper, NilapaHata lugens, to several rice varieties with different resistance background, after multi-generational selection on a resistant rice variety. A susceptible strain of brown planthopper (Dongjin-5) had been reared on the Chungchungbyeo with Bph1 resistance gene for three generations (Chungchung-G3) and six generations (Chungchung-G6), then the fitness change was evaluated by measuring their longevity, fecundity, preferences, and survivorships on the varieties with various background of resistance. After being selected three to six generations on Chungchungbyeo, feeding preference, adult longevity, and fecundity increased, where as nymphal period reduced when they were reared on various varieties with Bph1 gene. The egg Periods were not much different among the varieties fed on, except for the Chungchung-G6 on the rice varieties of Milyang63 (bph2 gene) and Gayabyeo (Bph1+bph2 gene). These results suggest that the susecptible Donajin-5 (Biotype-1) can be easily converted to a resistant biotype-2 capable of overcoming the resistant varieties with Bph 1 gene.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.113-118
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• 2006

The composition of fatty acids, minerals, total dietary fiber and vitamin $B_1,\;B_2$, in pigmented rice varieties were determined. Proximate composition and color were also compared among pigmented rice varieties. Crude protein contents of black rice were higher than those of red and white rice, especially, C3GHi line had the highest protein content. There were no significant differences in lipid and crude ash contents between pigmented and white rice. Black rice showed lower Hunter value L and b value compared with red, green and white rice. But, Green rice showed lower Hunter value a compared with black rice. Green rice showed the higher contents in total dietary fiber, vitamin $B_1\;and\;B_2$ compared with white and black rice. The major fatty acids of pigmented rice were palmitic acid, oleic acid and linoleic acid. The contents of oleic acid was similar to that of linoleic acid in white rice. Oleic acid contents was lower than linoleic acid in black rice, but higher in red rice. Most mineral contents of pigmented rice except Fe, Zn and Mn were higher than those of white rice. Especially, Green rice had the highest mineral content.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.214-222
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• 1998

These experiments were conducted to investigate water uptake, electrical conductivity, germination percentage, seedling growth, and seedling establishment rate in direct seeding cultivation of rice. The rice seeds of six japonica type varieties were coated with 12 kinds of polymers in a standard concentration of 0.2% using seed coating machine. The water absorption of the polymer-coated seeds under saturation conditions was not different among varieties, and was the highest in kulcel, maltrin, and waterlock on the polymer-coated seeds. The electrical conductivity with waterlock (55.0 $\mu scm^{-1}g^{-1}$) was higher than the control plot (45.6 $\mu scm^{-1}g^{-1}$) and other treatments. The germination of the polymer-coated seeds was 95.9% at control plot, 92.7% at low temperature and 35.7% at high temperature. The total dry weight of seed decreased in the order of low temperature, control plot, and high temperature, and was effective in pvp (polyvinyl pyrrolidone), opadry, and sacrust. The seedling establishment rate in direct seeding cultivation ranged from 74.9 to 81.0% in flooded paddy surface, and ranged from 64.7 to 76.6% in dry paddy. In both cases, it decreased in the order of early, medium and medium-late varieties, but was enhanced in daran 8600, sepirect, and sacrust. According to this study the recommended polymers for direct seeding cultivation of rice are daran 8600, sepirect, and sacrust.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.142-147
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• 2006

The present study describes carbohydrate metabolism, macro-element utilization and antioxidant defenses in response to an ozone dose (100 ppb, 8d) in two rice varieties. Tolerant (cv. Jinpumbyeo) and sensitive (cv. Chucheongbyeo) varieties of rice were grown in growth chamber for 30 days after sowing. Concentrations of chloroplast pigments and non-structural carbohydrates as well as activity of antioxidant enzymes were determined to evaluate the resistance against ozone stress. Ozone caused the decrease in chlorophyll a and carotenoid contents, and also resulted in faster decomposition of non-structural carbohydrate in leaf blade and leaf sheath. The contents of nitrogen and potassium in leaves were visibly decreased in cv. Chucheongbyeo with an increase in ozone exposure, but not in cv. Jinpumbyeo. Enzymatic antioxidants against ROS in both varieties responded in the order of POD, SOD and CAT, and their capacity was stronger in cv. Jinpumbyeo.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.218-222
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• 1982

It has been ascertained by a few researchers that soil salinities of the saline paddy fields have some effects upon the root development of the rice plants. But much is not known about the root formations of the rice plants in different varieties cultivated at the saline paddy field. Therefore this experiments were conducted to study the salinity tolerance of rice plants via variety test. Tested varieties were Akibare, Jinheung, Milyang #30, Josaeng Tongil, Suweon #264 and Suweon #287. And testing methods were cultivation experiment at the saline paddy field and leaf-cutting method at the laboratory. The results of cultivation experiment showed Milyang #30 and Josaeng Tongil were superior to others in root formation, and those of leaf-cutting method revealed that Josaeng Tongil and Mi1yang #30 were also superior to others in root formation and root length.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.901-906
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• 2010

The improvement of the fermentation quality of rice straw silage by application of lactic acid bacteria (LAB) and glucose was investigated in this study. Sixteen rice varieties were harvested at the maturity stage and the rice straw was ensiled with LAB inoculant ($1{\times}10^5$ cfu/g of fresh weight) and glucose (2% of fresh weight). Inoculation with LAB improved the fermentation as reflected in reductions in pH, acetic acid (by 3.7 to 78.3%), butyric acid (by -6.0 to 100.0%) and ammonia nitrogen (by 1.0 to 71.7%) concentrations, and increases in lactic acid (by 43.9 to 282.9%) and crude protein concentrations compared with the control. Application of LAB plus glucose was more effective in improving fermentation quality than LAB alone. The variety of rice straw which contained relatively high levels of water soluble carbohydrates (WSC) tended to obtain better fermentation quality. The results suggested that LAB application and selection of rice varieties whose straw contained high levels of WSC were effective in improvement of the fermentation quality of rice straw silage.