• Korean Journal Plant Pathology
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• 제10권1호
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• pp.47-53
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• 1994

Incidences of blast caused by Pyricularia grisea Sacc. on 24 leading cultivars and elite lines of rice were investigated in the fields at Icheon, chuncheon, Jecheon, Naju from 1990 to 1992. In the blast nursery, disease index of leaf blast on Jinmibyeo and Ilpumbyeo were very low as 1 to 3 at Naju, but as high as 6 to 9 at Icheon and other Chuncheon in 1990, but the disease did not occur in other locations and years. The most variable incidence of temporal and spatial leaf blast was observed on Nagdongbyeo, which was 30.6% at Icheon and 2.1% at Chuncheon on 1990, but the disease did not occur at Naju during the investigation. Percentages of diseased panicles on Chucheongbyeo were 11.6% in 1990 and 4.3% in 1992 at Icheon. Odaebyeo and Sobaekbyeo revealed more severe blast occurrences at Chuncheon and Sangju where the elevation was higher than the other places. Regional race distributions of rice blast fungus were more variable at Icheon and Chuncheon than the others.

• Applied Biological Chemistry
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• 제47권2호
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• pp.216-221
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• 2004

Changes in physiological functionality of giant embryonic rice by germination process were investigated using 70% ethanolic extract of the rices. Physiological functionality was evaluated by determining the reducing power, phenolic compound content, GABA content, and antimutagenicity. The results showed that the order of reducing power of the non-germinated rices was Nampung giant embryonic rice>normal rice> Whachung giant embryonic rice, however, the activity was high as the order of Whachung giant embryonic rice> Nampung giant embryonic rice> normal rice by germination process. About 3-fold activity increase was observed for Whachung giant embryonic rice, while, the activity of Nampung giant embryonic rice and normal rice decreased by the same treatment. The phenolic compound content of three rice cultivars were found to be almost same levels. Germination of rice increased the content of phenolic compounds by 2.6-fo1d without any considerable changes for both Nampung giant embryonic rice and normal rice. The GABA contents was highest in Whachung giant embryonic rice, followed by Nampung giant embryonic rice, normal rice in either germination or non-germination condition. The germination increased the GABA contents by more than 2.4-fold for all rice cultivars tested. We also found an increase in the antimutagenic activity by germination process for all cultivars, where the activity was the greatest for Whachung cultivar.

• Korean Journal of Breeding Science
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• 제41권4호
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• pp.488-495
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• 2009

In recent years, an increasing amount of research has been conducted on the yield loss of soybean crop caused by Riptortus clavatus, a serious pest of legumes. The objective of this study were to examine crop damage caused by various population densities of R. clavatus and determine the association of unique growth and seed characteristics with crop damage rate in conventional soybean fields. Major growth responses to R. clavatus were examined. The cultivars that were not as seriously damaged by R. clavatus were Pungsannamulkong, Sobaegknamulkong, Duyoukong, and Sinpaldal 2, but Myeongjunamulkong, Mallikong, and Hwangkeumkong were significantly (P<0.05) damaged. The rate of seed damage caused by R. clavatus was 8.2% in a group of brown colored pubescence, while the rate was 13.0% in a group of the gray colored. Crop damage by R. clavatus clearly more reduced in cultivars with dark hilum colors including dark brown, brown, and grayish brown than those with yellow hilum colors. Concerning pod colors, crop damage was less significant in cultivars with dark brown pod color than with the light brown. Cultivars with short pod length (4.0-4.5 cm) at full seed (R6) stage showed lower seed damage rates by R. clavatus than those with long pod length (>5.6 cm). Therefore, characteristics of hilum, pod, pubescence colors, and pod length were significantly related and linked to the cultivar resistance to R. clavatus.

• Proceedings of the Korean Society of Crop Science Conference
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.229-229
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• 2017

This research study was conducted to analyze the characteristics of different rice cultivars in abnormal temperature conditions (low temperature) for ripening period abnormalities, and to investigate the physiological causes behind the abnormalities. Four Korean high quality japonica-type rice cultivars, Jinbu (JB), Junamjosaeng (JJ), Geumyoung (GY), Hwawang (HW) were used in the experiment. The following day after flowering, they were then moved into two phytotrons under natural daylight with 65% RH but controlled at different temperatures - one at $19/29^{\circ}C$ (night/day) and the other at $13/23^{\circ}C$ as the low - temperature study on ripening. For the cultivars at $13/23^{\circ}C$ (low temperature study), JB and JJ had a ripening rate of 93% which is similar to the ripening rates of cultivars at $19/29^{\circ}C$ at 45 days after heading (DAH). In contrast, GY and HW recorded lower ripening rates of 86% and 57% respectively. However, when the cultivars at $13/23^{\circ}C$ were harvested at 61 DAH (when the accumulated temperature reached $1100^{\circ}C$), the difference in ripening rates compared to the 4 cultivars of $19/29^{\circ}C$ harvested at 45 DAH was not obvious (JB 94%, JJ 97%, GY 97%, HW 88%). Starch content showed little difference among the 4 cultivars at different temperature conditions while amylose content was higher for cultivars at $13/23^{\circ}C$ compared to those at $19/29^{\circ}C$. In addition, the enzyme activities of starch biosynthesis were about 5~10 days slower in cultivars at $13/23^{\circ}C$ compared to cultivars at $19/29^{\circ}C$. The grain-filling rate showed highly significant correlations with the enzyme activities of Sucrose synthase ($R^2=0.70^{***}$), ADP glucose pyrophosphorylase ($R^2=0.63^{***}$), UDP glucose pyrophosphorylase ($R^2=0.36^{***}$), Starch synthase ($R^2=0.51^{***}$), and Starch branching enzyme ($R^2=0.59^{***}$). Among the enzymes, Sucrose synthase activity had the highest correlation coefficient with grain-filling rate. In conclusion, the activity of enzymes such as Sucrose synthase, UDP glucose pyrophosphorylase, ADP glucose pyrophosphorylase, Starch synthase, Starch branching enzyme in starch biosynthesis is proven to be highly related to the grain filling process. Notably, the decrease in the activity of Sucrose synthase and Starch branching enzyme and the late increase in ADP glucose pyrophosphorylase activity at low temperature in the ripening stage are considered to be disadvantageous as they delay ripening and increased amylose content.

• Proceedings of the Korean Society of Crop Science Conference
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.184-184
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• 2017

Organic matter is very important and essential factor to maintain productivity of paddy field. But as meat consumption and the demand of grain increase, the demand of forage also increased gradually in Korea. So the amount of organic matter in paddy field have been declined gradually by the reduction of return of rice straw for the forage use for cattle. There is not enough alternative resources for forage, we guess this trend of organic matter decline in paddy field would continue for the time being in Korea. So this study was performed to confirm the variation of organic matter and change of rice yield to select suitable rice cultivars which yield reduction is small in condition of organic matter decrease in paddy field. To confirm the change of rice growth and yield in condition of organic matter decrease in paddy field, we transplanted 10 rice cultivars which yield reduction are small in low fertilizer condition. We transplanted it Buan where double cropping of winter barley continues several years on June 10. Planting density were $70plants/3.3m^2$ Fertilizer amount was $N-P_2O_5-K_2O=9-4.5-5.7kg/10a$ and fertilizer split application of nitrogen was basal-tillering stage-panicle initiation = 50-20-30%. And in the other cultivation management, we observed rice standard culture of NICS. In paddy field where withdraw straws of barley and rice, the organic matter content showed tendency to decrease as the years go on. During rice cultivation season, organic matter decreased little by little, but it increased again after rice harvest season. Rice yield was more in order of Sodami, Chunghaejinmi and Saenuri. We judge that there is an advantage in rice yield of rice cultivars which have later heading date because of suitable ripening temperature. Although Sobibyeo and Shindongjinbyeo showed high yield, head rice yield decreased severely owing to chalky and cracked rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제53권3호
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• pp.326-332
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• 2008

This study was conducted to evaluate an early-maturing rice cultivars adaptable to early transplanting cultivation in Yeongnam plain area. High temperature during the ripening stage of paddy rice under the early-transplanting cultivation in Yeongnam plain was to influence in several agronomic traits such as number of spikelet, ripening ratio, grain appearance of milled rice, and yield. 'Gounbyeo' and 'Junghwabyeo' were better than the others in grain appearance of milled rice and ripening ratio, but their yield potential were lower than that of the other varieties. Moreover, 'Gounbyeo' and 'Junghwabyeo' showed high ratio of broken rice. 'Unkwangbyeo' was the highest in yield and eating quality among the tested varieties, but also high percentage of white core and belly in milled rice. Therefore, in order to recommend those cultivars to farmers, it should be needed to establish an optimal cultivation method, such as transplanting density, fertilizer application, and harvesting time, etc. consequently, it should also be required to develop a new varieties with high ripening capability under high temperature condition.

• Korean Journal of Food Science and Technology
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• 제48권1호
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• pp.20-26
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• 2016

This study invesigated the physicochemical properties of rice flours from conventional and high-yielding rice varieties in order to enhance usability processing of high-yielding rice varieties. Moisture content was not remarkably different among rice flours by cultivar. The highest content of total free sugars was detected in Hopum rice. Apparent amylose content of Anda was higher than that of other rice varieties. The total amount of amino acids was highest in Anda rice among the rice cultivars. Contents of vitamin $B_1$ in Hanarum were highest among the rice cultivars. Initial pasting temperature was lowest in Anda rice ($60.10^{\circ}C$). Hanarum rice showed the lowest setback values among the rice flours. Therefore, Anda and Hanarum rice cultivars were suggesting the possibility of a processed rice food source.

• Weed & Turfgrass Science
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• 제5권4호
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• pp.187-190
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• 2016

This study was conducted to determine phytotoxicity of domestic rice varieties and characteristic of sensitive gene involved in herbicide reaction of 4-HPPD (4-hydroxy phenylpyruvate dioxygenase) inhibiting herbicides. The five rice varieties were grown for 2 to 3 leaf stage on seedling trays and then transplanted into plastic pot: 4-Japonica type (Sangjubyeo, Sambaekbyeo, Sanduljinmi and Kumyoung) varieties and 1-Indica type variety (IR8). We trialled standard (14 g a.i. $10a^{-1}$) and double fold (28 g a.i. $10a^{-1}$) dose of benzobicyclon treatment at 10 days after transplanting in order to investigate phytoxicity. The Japonica-type Sangjubyeo showed no rice injury but Indica-type IR8 show 4-5 (standard) and 5-6 (double fold) phytoxicity levels. In spite of Japonica-type, Sanduljinmi and kumyoung showed 3-4 and 4-5 levels. Target resistant gene, Hydroxyphenylpyruvate dioxygenase inhibitor sensitive gene No.1 (HIS1) have been isolated from five domestic rice cultivars (Sangjubyeo, Sambaekbyeo, Sanduljinmi, Kumyoung and IR8). Results of the sequence through PCR, all five tested rice cultivars had HIS1 gene regardless to rice cultivars. And the difference between rice varieties from sequence of HIS1 were identified some variation in genes.

• Korean Journal of Food Science and Technology
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• 제9권2호
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• pp.144-152
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• 1977

The physiochemical properties of eight different cultivars or newly bred lines of glutionous rice were investigated and obtained following results; (1) The gelatinizing temperature, blue value and alkali number of starch separated from the sample cultivars or lines were similar to those of starch from conventional cultivar Olchal. The expansive power of three newly bred lines were somewhat weaker than that of starch from conventional cultivar, but the expansive power of other four lines were similar to that of conventional cultivar. (2) pH of cooked rice of the ten sample cultivars or breeding lines showed no discernible differences rangeing from 6.54 to 6.60. (3) The degree of gelatinization of cooked rice of newly bred lines were rather lower than that of conventional ones, but the degree of their retrogradation were somewhat higher than that of conventional cultivars. (4) In order to improve the palatability of cooked rice of Tongil (common rice), glutinous rice were mixed in different rate. The results showed that a mix ratio of six per cent glutinous rice was most favourable. The acceptability of common Tongil rice was improved when it was cooked with four to six per cent of glutinous rice mixed, and it showed no significant difference from that of Akibare alone cooked rice. Also no difference was noticed among newly bred glutinous lines in the acceptability when they cooked with common Tongil rice mixed. (5) Injolmi, Yaksik, Misitgaru, Twipap and Yugwa were prepared from glutinous rice of sample cultivars and or breeding lines to study their characteristics in processing and their acceptability. The results indicated that the acceptability score of newly bred lines were lower than that of conventional cultivar in cases of Twipap and Yugwa, but in cases of Injolmi, Yaksik and Misitgaru, identical score was obtained from both of newly bred lines and conventional cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제66권4호
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• pp.297-306
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• 2021

To select rice (Oryza sativa L.) cultivars suitable for forage-rice double cropping system, the growth and grain quality of four early maturing rice cultivars (Joun, Jopyeong, Haedamssal, and Unkwang), and the chemical properties of soils were investigated under single- (fallow-rice) and forage-rice double-cropping systems in paddy fields in Miryang, southern Korea. The soil where two forage crops [Italian ryegrass (Lolium multiflorum Lam.) and oat (Avena sativa L.)] were cultivated during winter had a slightly lower pH; an increase in total nitrogen (T-N), K, Ca, and Na contents; and a slight decrease in organic matter and available P₂O₅ contents, compared with the soil fallowed during winter. This shows that the chemical properties of paddy soils can be improved by winter forage cropping. At the heading stage, the culm length, panicle length, panicle number, and leaf color of all cultivars, except for Haedamssal, were generally higher under double-cropping than under single-cropping. For Haedamssal, the culm length and leaf color did not differ between the cropping systems, but the panicle length was slightly shortened and its panicle number increased under double-cropping. After harvest, the yield of milled rice decreased for all cultivars except Haedamssal, but increased in Haedamssal under double-cropping. The head rice rate was slightly higher under double cropping, particularly in Jopyeong and Haedamssal, than under single-cropping. The protein content of milled rice under double cropping was higher and its amylose content was similar or slightly lower compared to those of rice under single cropping, resulting in decreased Toyo values for rice under double-cropping. The pasting temperature did not differ significantly between the cropping systems. However, Haedamssal had a low pasting temperature but a high Toyo value under double cropping, compared to the other three cultivars, suggesting that its palatability is relatively high. Furthermore, panicle number increased and milled rice yield did not decrease, even under double cropping. Therefore, Haedamssal seems to be the best cultivar for paddy-based double cropping with forage crops.