• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.269-276
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• 2008

Field resistance is defined as the resistance that allows effective control of a parasite under natural field condition and is durable when exposed to new races of that parasite. To identify the genes for field resistance to rice blast, quantitative trait loci (QTLs) conferring the resistance for races and blast nursery screening in japonica rice cultivars were detected and mapped using SSR markers. QTL analysis was carried out in 190 RILs population from the cross between Suweon365 (moderately resistant) and Chucheong (highly susceptible). Twelve QTLs against nine blast races inoculated were detected on chromosomes 1, 2, 4, 6, 7, 11 and 12. They explained from 5.1% to 34.9% of total phenotypic variation. Eight QTLs against blast nursery screening in four regions for three years were detected on chromosomes 1, 2, 4, 11 and 12. The phenotypic variation explained by each QTL ranged from 4.3% to 37.7%. Three chromosome segment substitution lines (CSSLs) of $BC_2F_6$ by backcross method were developed to transfer the QTLs into the susceptible cultivar Chucheong as a recurrent parent. A CSSL4-1 containing two QTLs qLB6.2 and qLB7 against blast races showed to the reaction of 6 to 7 at blast nursery in two regions for two years. The CSSL4-2 and CSSL93 containing QTLs, qLB11.2 and qLB12.1 of the resistance against leaf blast in blast nursery screening, respectively, had enhanced the resistance for blast nursery screening across two regions and in two years.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.121-121
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• 2017

The productivity of rice has been influenced by various abiotic factors including temperature which cause to limitations to rice yield and quality. Rice yield and quality are adversely affected by high temperature globally. In the present study, four Korean four cultivars such as Dongan, Ilpum, Samkwang, Chucheong were investigated in order to explore molecular mechanisms of high temperature at seedling stage. Rice seedlings grown at $28/20^{\circ}C$ (day/night) were subjected to 7-day exposure to $38/28^{\circ}C$ for high-temperature stress, followed by 2-D based proteomic analysis on biological triplicates of each treatment. The growth characteristics demonstrated that Dongan is tolerant while Ilpum is sensitive to high-temperature stress. High temperature has an adverse effect in the seedling stage both in high temperature sensitive and tolerant cultivar. Two-dimensional gels stained with silver staining, a total of 722 differential expressed protein spots (${\geq}1.5-fold$) were identified using Progenesis SameSpot software. However, a total of 38 differentially expressed protein spots were analyzed by LTQ-FT-ICR MS. Of these, 9 proteins were significantly increased while 10 decreased under high-temperature treatment. Significant changes were associated with the proteins involved in the carbohydrate metabolism, photosynthesis, and stress responses. Proteome results revealed that high-temperature stress had an inhibitory effect on carbon fixation, ATP production, and photosynthetic machinery pathway. The expression level of mRNA is significantly correlated with the results obtained in the proteome investigation. Taken together, these findings provide a better understanding of the high-temperature resistance by proteomic approaches, providing valuable insight into improving the high-temperature stress tolerance in the global warming epoch.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.351-359
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• 1991

Demand for the rice of better eating quality is ever increasing in recent years. However. the rice is presently handled by the government and merchants as mixture of the rice of different varieties from the purchase of the rough rice to storing and milling. It is well known that the eating quality of rice varies significantly by variety. The present study aimed at evaluation of the effect of blending different rices on the change in palatability of low and high eating quality rices. The eating quality of a low quality japonica rice was improved significantly on sensory panel test by blending it with the Dongjin rice. one of the highest eating quality. only when the Dongjin was blended to 80 percent by weight. and also it was same for blending an ordinary quality rice of mixed varieties which has been stored by a governmental storehouse with a top class rice on free market. The eating quality of aged Tongil type rice. produce of 1987 and 1989 and a mixture of varieties, was improved significantly by blending it with a high quality glutinous rice on market to 20 per cent by weight. But Samgang rice. a high eating quality Tongil type variety. and an ordinary quality rice of Japonica varieties were not significantly improved by blending them with the glutinous rice by 20 per cent. Blending rices of the variety Nagdong. ordinary quality among varieties and low quality among Japonicas, Chucheong, a high quality rice among Japonicas. and Dongjin. one of the best eating quality rice among Japonicas, each other in different ratios did not affect significantly the sensory scores.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.516-519
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• 2009

This study was conducted to investigate the effects of replacing whole crop corn silage (WCCS) with whole crop rice silage (WCRS) in the total mixed ration (TMR) on nutrient intake, milk yield and its composition in Holstein cows. The Chucheong rice variety (Oryza sativa L. Japonica) and corn (Pioneer 32 P75) were harvested at yellow-ripe stage and were ensiled in round bales and in trench silos, respectively. Two TMR containing either WCCS or WCRS were prepared. These diets were randomly assigned to 16 midlactating Holstein cows (8 cows per treatment) and were fed for 120 days. The first 20 days were used for dietary adaptation and for the next 100 days daily feed intake, milk yield and its composition were recorded. The pH, lactic acid, NDF, ADF, CP, Ca and P contents were similar in WCRS and WCCS. The DM, ash and EE contents of WCRS were greater compared with WCCS. Nutrient (DM, NDF, TDN and CP) intakes were similar in cows fed WCCS- and WCRS-based TMR. Daily and 4% fat corrected milk yield were not affected by the treatments. Milk composition (percent milk fat, protein, lactose and total solids) was similar in cows fed either WCCS- or WCRSbased TMR. The concentration of milk urea N was greater in cows fed WCRS-based TMR than those fed WCCS-based TMR. In conclusion, round-baled WCRS can replace WCCS in the diet of mid- to late-lactating Holsteins without any deleterious effects on feed consumption, milk yield and its composition. The present findings raise the possibility that WCRS can be used as an alternative roughage source in the diets of dairy cows in countries with surplus rice production.

• Korean journal of applied entomology
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• v.24 no.4 s.65
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• pp.209-218
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• 1986

This study was performed to evaluate the differences in resistance of rice varieties to biotypes of the brown planthopper (BPH), capable of surving on the Milyang 30 and Milyang 63 varieties which have Bph 1 and bph 2 gene for resistance, respectively. The rice varieties tested were Milyang 30, Cheongcheong, Milyang 63 and Gaya which have been reported as having resistant genes for the BPH. The check varieties were Chucheong and Sangpoong which have no resistant gene. The degree of resistance to the BPH biotypes indicated that Milyang 30, Cheongcheong, Milyang 63 and Gaya varieties were highly resistant to the biotype 1. But their reactions against biotype 2 and 3 were variable, namely Milyang 30 and Cheongcheong were susceptible to biotype 2, and Milyang 63 was susceptible to biotype 3. In the esterase isozyme patterns of brown rice the bands of ${\beta}-1,\;{\beta}-3\;and\;{\beta}-5$ were detected in Chucheong and Sangpoong, while the bands of ${\alpha}-1,\;{\beta}-2\;and\;{\beta}-5$ were detected in the test varieties which have genes for resistance. However, the bands of ${\beta}-5$ in Milyang 63 and Gaya were stronger than those of Milyang 30 and Cheongcheong varieties. In the root of 10-days seedling, the esterase bands of ${\alpha}-2,\;{\beta}-2\;{\beta}-4\;and\;{\beta}-5$ were detected in Chucheong and Sangpoong, while the bands of ${\alpha}-1,\;{\beta}-1\;{\beta}-3\;and\;{\beta}-5$ were detected in the tested different varieties. But the bands of ${\alpha}-1\;and\;{\beta}-5$ in Milyang 63 and Gaya were stronger than those of Milyang 30 and Cheongcheong varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.266-270
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• 1991

Storage in the form of brown or milled rice saves space and cut cost rather than storage of rough rice, the common way of grain storage in Korea. But, brown or milled rice may be more susceptable to grain aging and sensory change than rough rice. Rice stored in government warehouse for 20 months after harvest was hulled into brown or milled rice and packaged with kraft paper bag (paper package), polyprophylen (PP package), and polyethylene (PE package). Then, after those rice packages were stored under room condition for one year, we investigated germinability, fat acidity, and sensory change to determine milling and packaging effects. Germinability of rough and brown rice was decreased significantly after long-term storge. In germination rate, Chucheong cultivar was lower than Milyang #23, brown rice was lower than rough rice, but there was no differences within packaging materials. TTC test which had a significant correlation with germinability can be used as a handy procedure for predicting grain germination. Fat acidity was increased as the order of rough < milled < brown rice in terms of milling, and PP < paper < PE package in terms of packaging materials. Especially, storage of brown rice increased fat acidity above 30 mg KOH, indicating one of characteristics of grain aging. To prevent from high fat acidity it was necessary to store in forms of rough grain with paper or PP packaging and milled rice with paper, or PP, or PE packaging. In sensory test of stored grain, eating quality in brown rice was the worst because of acidification of fatty acid. Also, eating quality of stored grain became worse as fat acidity increased.

• Korean journal of applied entomology
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• v.25 no.2 s.67
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• pp.93-98
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• 1986

The densities of plant-and leaf hoppers were examined by direct counting the rice plant of two varieties; Milyang 23 and Chucheongbyeo, in Chinju. The densities of the small brown planthopper(SBPH), Laodelphax striatellus, and Green rice leafhopper(GLH), Nephotettix cincticeps were higher on Chuchungbyeo than on Milyang 23 throughout the season, whereas those of white backed planthopper(WBPH), Sogatella furcifera, and Brown planthopper(BPH), Nilaparvata lugens were high on Milyang 23. Seasonal densities of planthoppers were varied with rice plant growth; on Chucheong field, GLH was the predominant species from June to August and BPH was in September, but in Milyang 23 field, WBPH was more abundent from July to August and BPH was increased from late August and was the highest on September.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.3
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• pp.79-88
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• 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 Soil Science and Fertilizer
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• v.23 no.1
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• pp.26-33
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• 1990

The pot experiment was conducted to compare the effects of BIO-COM (Organic fertilizer made from industrial by-product) with the compost and humic acid on the physico-chemical properties of soils and the yield of paddy rice (CV. Chucheong-byeo). The results obtained were as follows: 1. All the fertilizer treatments, except humic acid, increased rice yield compare to no fertilizer treatment, and Bio-Com was the highest among the fertilizer treatments. 2. Rice yields were increased with increasing BIO-COM only up to 4% but 2% with N.P.K. fertilizers. 3. Rice yield showed highly positive correlation with number of panicle per hill but negative correlation with 1000 grain weight. 4. BIO-COM application induced the noticeable increase of pH, EC, OM, T-N, Av-P, Ex-Ca, Ex-Mg, Ex-Na, and $Av-SiO_2$, contents in the soils after experiments, and there were highly significant positive correlation among them. 5. BIO-COM application was positively affected on plant height, number of tiller, and fresh weight and dry weight of rice plant throughout entire growing stages and these are positively correlated with rice yield. 6. BIO-COM application also induced the increase of chlorophyll, N, P, Ca, and Mg contents in rice plant 7. It is revealed that there were highly positive correlations between rice yields and pH, EC, OM, T-N, Ex-Ca, and Ex-Mg in the soils. 8. It was also shown the highly significant positive correlations between rice yields, and N and P contents in the rice plant at heading stages, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.1
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• pp.29-34
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• 2008

This experiment was conducted to study the effects of growth stage and variety on the quality of whole crop rice(WCR) silage at National Institute of Animal Science, RDA from 2004 to 2005. Two types of rice("Chucheong" for food and "Hamasari" for whole crop) were harvested at six different growth stages (heading, flowering, milk, dough, yellow ripen and fully ripen stage) and ensiled each harvest stages. Crude protein(CP) content of all whole crop rice silage was also decreased with progressed maturity at harvest and TDN(total digestible nutrient) content of WCR was increased. The average CP content of whole crop rice was higher than that of food rice. The contents of ADF(acid detergent fiber) and NDF(neutral detergent fiber) decreased with delayed harvest maturity. The content of TDN estimated from ADF content was increased with progressed maturity, but there was not found significant difference between rice varieties(p<0.05). The average pH value was 4.69 and it was increased with delayed harvest maturity. Acetic and butyric acid content were decreased, but lactic acid content was increased with progressed maturity. The experiments presented here show that all rice varieties may give a good quality silage. But some wrong practical method(grain loss, productivity, nutrient value, etc.) will make poor quality of rice silage. Therefore, dough stage of harvest maturity will be recommendable as proper harvest time for making high quality of whole crop rice silage in Korea.