• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.250-253
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• 1998

Somaclonal variation was observed in the field on doubled haploid plants derived from single pollen of a rice cultivar "Hwaseongbyeo". The variations of seven quantitative traits including plant height and one qualitative trait (pubescence) in 436 lines ($R_2$ generation) were analyzed. The number of lines which fell beyond the boundaries of the 95% confidence intervals of the check variety, Hwaseongbyeo was checked for each quantitative trait, and of those fertility showed the highest variation frequency (85.6%), followed by plant height (77.5%), flag leaf length (66.5%), grains per panicle (42.2%), days to heading (34.5%), panicle length (30.7%) and panicles per hill (22.7%). And the variations of quantitative traits except days to flowering appeared to move in the negative direction compared to "Hwaseongbyeo". Variability within lines was also observed for quantitative and qualitative traits. Twenty-nine $R_2$ lines (7%) segregated for pubescence and 130 $R_2$ lines (30%) showed variation with regard to fertility. This suggests that mutations usually occur before diploidization. Twenty-nine $R_2$ lines representing a wide spectrum of variation were chosen for RAPD analysis. The number of lines showing DNA polymorphism compared to Hwaseongbyeo ranged 0 from to 10 according to the primer used and this seems to indicate that specific loci have highly mutable genomic site.utable genomic site.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.1 no.1
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• pp.46-48
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• 1963

1. In this experiment, the effect of the fertilizer of which the chief ingredients are the silicate, the manganeize and the iron, was examined by applying to the rice variety Norm ＃6, in three different vote as 377 gr, 754 gr and 1131 gr per 0.22 a. 2. In the rearing of the rice plant, the effects of the fertilizer was not so significant in the plant height or division. 3. The rice blast and the leaf spot was decreased by appling this fertiliger and the lager dose, the less significantly. 4. The fruiting-rate, yield, and the perfect unpolished-rice weight were increased by appling this fertilizer, and the whole unpolished rice weight and the perfect unpolished rice weight was inproportion to the amount of the fertilizer.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.379-384
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• 1983

Textural changes of glutinous rice cakes during storage at $4^{\circ}C$ were evaluated by ${\beta}$-amylase digestibility and hardness. Some physical properties of starch including X-ray diffraction, swelling power, water holding capacity and gelatinization temperature were investigated. Changes in hardness were inversely related to the enzyme digestibility. The initial hardness for Tongil glutinous rice cake is much higher than that for Traditional one. Both parameters were changed rapidly during one and two days of storage for Tongil and Traditional glutinous rice cakes, respectively. These results implied that the differences in the strach structure might have significant influences on the texture of rice cakes. Sensory evalution revealed that hardness of the rice cakes was highly significant to the storage time and rice variety.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.62-67
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• 1985

Hydration rate of 35 Japonica and 24 J x Indica rice varieties at $23^{\circ}C$ was investigated and an attempt was made for a tentative classification of milled rice into six groups based on hydration rate. Each rice variety had characteristic value for hydration rate. In general, J x Indica rice hydrated at a faster rate than Japonica rice. Hydration rate was negatively correlated with the ratio of length to width of rice grain. No correlation was found between hydration rate and protein, amylose, surface area, volume or initial water grain.

• Journal of Biosystems Engineering
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• v.27 no.2
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• pp.125-132
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• 2002

In order to investigate the optimum moisture content of paddy for milling process, a series of tests were conducted by examining the recovery rate and whiteness of milled rice in relation with the various moisture content. Hwabong-byeo and Dongjin-byeo varieties which were major paddies cultivated in Korea were used for the experiment. The test was performed with small experimental milling machines. In order to minimize the unexpected factors, environment conditions were kept in constant during the experiment. As a result, the recovery rate of milled rice were varied as the changes in milling time and degree of whiteness. However, the recovery rate of milled rice increases as its moisture content increases untill a certain point of moisture content and decreases slowly afterward. This certain point can be called optimum moisture content for rice milling. Also, it has a different value depending on the variety. In this experiment, optimum moisture content of Hwabong-byeo and Dongjin-byeo were considered around 14.8% and 15.3%, respectively. It is not sure that these optimum moisture contents for the two varieties would assume the same values irrespective of harvest year and place. However, it could be concluded that the optimum moisture content for rice milling is around 15%(w.b.) for Hwabong-byeo and 15.5%(w.b.) for Dongjin-byeo, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.200-215
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• 2002

There are some international standards and organization controling the quality characteristics of varieties and seeds such as UPOV, OECD, ISTA, AOSA. The National List system to check variety performance such as quality characteristics of plant varieties and seeds was established by each countries. The UPOV (International Union for the Protection of New varieties of Plant) regulates the requirement of plant variety protection that is distinctness (D), uniformity (U), stability (S) (here in after called DUS), Novelty and Denomination, and some quality characteristics are used to examine the requirement of plant variety protection by each crops. OECD (Organization for Economic Cooperation Development) seed scheme regulates the seed certification for seed trade between countries. ISTA (International Seed Testing Association) and AOSA(Association for Official Seed Analyst) regulates the seed analysis standard and methods. Most of the countries in Europe has the National List system, which check the value for cultivation and use(VCU), that is to say, variety performance such as yield, quality and stress to environment. All the seeds should be enlisted in the National List before sell the seed in their country. All the quality characteristics checked variety performance are for instance, amylose and amylopectin content in rice, molting quality, $\beta$-glucan, protein in barley, protein and sugar content in soybean, sugar and amylopectin content in corn etc. Conditions for the protection of new variety of plant are DUS. Quality characteristics may be the important characteristics and used to check DUS in crop by crop. It is very important to develop a new characteristics and establish standard method fur examine the VCU and DUS test for each crop.

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.2
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• pp.86-95
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• 1983

Evapotranspiration is a major factor determining the water consumption in the rice fields. Therefore, realistic evapotranspiration estimates are important to the agricultural water resources planning. In Korea, however, the Blaney-Criddle formula, which was developed under the meteorological condition of western arid United States and the upland cultivation, has been widely used to estimate evapotranspiration from paddy fields. Hence, it has considered that the Blaney-Criddle formula would not be the proper method for the Korean paddy condition. The purpose of this study is to select the most appropriate and realistic method for estimating evapotranspiraion from paddy field in Korea and to derive crop coefficients using the chosen method. The results are summerized as follows. 1. Total seasonal-average evapotranspiration by the field observation was 660mm for Tongil and 621. Ornm for the Japonica variety of rice. The amount of evapotranspiration for Tongil variety was 6% larger than that of the Japonica variety. 2. There was no significant differences in the amount of evapotranspiration among early, middle and late mature varieties, that is, early 638mm, middle 627mm and late 630mm for the whole growing season. 3. The rate of peak evapotranspiration appeared at the beginning of August and was in the range of 7.7-8. Omm/day according to the different mature varieties. 4. The correlation between pan evaporation data and the calculated evapotranspiration using related meteorological data from various methods suggested such as Radiation (FAO), Hargreaves, Christiansen, Hargreaves-Christiansen, Jensen-Haise, showed high statistic significance. Therefore, it seemed to use those formulars in estimating evapotranspiration inste4 of using pan evaporation data. 5. It was concluded from the analysis of field data that the evapotranspiration estimate for Blaney-Criddle method might not be appropriate in Korea. On the other hand, Penman equation showed more accurate estimation at the flourishing stage of rice than the pan evaporation method. 6. The crop coefficients for the Penman and pan-evaporation method were obtained by graphical representation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.31-31
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• 2018

The purpose of this study was to statistically analyze amylose and protein content of rice variety resources collected from China (1,542), Japan (1,409), Korea (413), and India (287). The statistical analysis was conducted using ANOVA and DMRT based on the data obtained from NIRS analysis. The average amylose contents were 18.85% in Japanese, 19.99% in Korean, 20.27% in Chinese, and 25.46% in Indian resources. The average protein contents were 7.23% in Korean, 7.73% in Japanese, 8.01% in Chinese, and 8.17% in Indian resources. The amylose and protein content using ANOVA showed significant differences at the level of 0.01. The F-test for amylose content was 158.34, and for protein content was 53.95 compared to critical value 3.78. The amylose and protein content using DMRT (p<0.01) showed significant difference between countries. The value of statistical treatment was divided into three groups such as $China^a$, $Korea^a$, $Japan^b$, $India^c$ in amylose and $China^a$, $India^a$, $Japan^b$, $Korea^c$ in protein. Japanese resources had the lowest level of amylose contents, whereas, the lowest level of protein content was found in Korean resources compared to other origins. Indian resources showed the highest level of amylose and protein contents. It is recommended that these results could be helpful to future breeding experiments.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.13-13
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• 2022

Recently, stable crop production is threatened by the effects of climate change. In particular, it is difficult to consistently maintain agricultural policies due to large price fluctuations depending on the difference in total domestic rice production from year to year. For stable rice production amid changes in the crop growing environment, development of varieties with improved disease resistance and abiotic stress stability is becoming more important. In here, drought and cold tolerant trait have been studied. First, for the development of drought tolerant varieties, we analyzed which agricultural traits are mainly affected by domestic drought conditions. As a result, it was observed that drought caused by the lack of water during transplanting season inhibits the development of the number of tiller and reduces the yield. 'Samgang' was selected as a useful genetic resource with strong drought tolerant and stable tiller number development even under drought conditions by phenotype screening. Three of drought tolerant QTLs were identified using doubled haploid (DH) population derived from a cross between Nacdong and Samgang, a drought sensitive and a tolerant, respectively. Among these QTLs, when qVDT2 and qVDTl1 were integrated, it was investigated that the tiller number development was relatively stable in the rainfed paddy field conditions. It is known that the high-yielding Tongil-type cultivars are severely affected by cold stress throughout the entire growth stage. In this study, we established conditions that can test the cold tolerance phenotype with alternate temperature to treat low temperatures in indoor growth conditions similar to those in field conditions at seedling stage. Three cold tolerant QTLs were explored using population derived from a cross between Hanareum2 (cold sensitive variety, Tongil-type) and Unkwang (cold tolerant variety, Japonica). Among these QTLs, qSCT12 showed strong cold tolerant phenotype, and when all of three QTLs were integrated, it was investigated that cold tolerant score was relatively similar to its donor parent, Unkwang, in our experimental conditions. We are performing that development of new variety with improved cold tolerant through the introduction of these QTLs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.4
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• pp.261-266
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• 2000

This study was to investigate antioxidative activity of rice grain using 1, 1-Diphenyl-2-picrylhydrazyl(DPPH) and thiobarbituric acid (TBA) method and germination ability for screening rice varieties with high antioxidative activities on korean native and foreign rice varieties harvested in 1998 and 1999. The average antioxidative activity of foreign rice varieties (DPPH 63.5% and TBA 55.2%) was significantly higher than that of native rice varieties (DPPH 47.2% and TBA 45.6%) on varieties harvested in 1999. The promptness index (PI) of native rice varieties was higher in stored rices for three months (mean PI=160.7) than that of stored rices for a year (mean PI=141.6). On the other hand, the PI of foreign rice varieties was higher in stored rices stored for a year (mean PI=176.7) than that of stored rices for three months (mean PI=157.5). Varieties with high redness of hulled rice (a-value) showed significant lipid peroxidation inhibitory activity to DPPH in a stored rices for a year (r=${0.5744}^**$) and stored rices for three months (r=${0.5630}^**$) . These results indicate that the pigments of hulled rice varieties may play important antioxidative roles and colored rice varieties with higher antioxidative potentials can be developed and also may provide information with rice breeder to breed rice variety with a high antioxidative activity for a rapid screening of a small amounts of a large number of samples using color value.