• Korean journal of applied entomology
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• v.31 no.3
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• pp.256-275
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• 1992

Insects are among the most important abiotic and biotic constraints to rice production. National rice research programs are in various stages in the development and implementation of integrated pest management (IPM) stratagies for rice insect control. Among the various control tactics, insect resistant cultivars are sought as the major tactic in rice IPM. Through the activities of interdisciplinary teams of scientists significant progress has been made in the development and release of insect resistant cultivars to farmers. Because of its compatibility with other control tactics insect resistance has proven to fit well into the IPM approach to rice insect control agents and minimize the need for insecticide applications. The development of biotypes which overcome the resistance in rice plants has been a significant constraint in the breeding of rice for resistance to insects. Most notable examples in Asia are the green leafhopper, Nephotettix virescens, brown planthopper, Nilaparvata lygens and the Asian rice gall midge, Orseolia oryzae. The current breeding stratege is to develop rice cultivars with durable resistance on which virulent biotypes cannot adapt. In spite of the significant progress made in the breeding of insect resistant cultivars there are still numerous important rice insect species for which host plant resistance as a control tactic has not been fully utilized. Advances in biotechnology provide promise of solving some of the problems that have limited the use of host plant resistance as a major tactic in the integrated management of rice insect pests.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.69-74
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• 2000

Varietal difference in physicochemical characteristics of glutinous rice grain and interrelationships between these properties and the quality characteristics of Yukwa(fried rice cookie) were investigated on fourteen rice varieties, to obtained the basic informations for diversifying the utility of glutinous rice grain and for developing various glutinous rice cultivars adaptable to glutinous rice food processing. Among physicochemical properties of glutinous rice grain, the content of released reducing sugar during soaking treatment was the most positive correlation between the adaptability to Yukwa processing quality. CB243 and Sandong 71 were the most adaptable glutinous rice cultivars to make the Yukwa, because of its tested score in expansion volume, crispiness and sensory preference was higher than other glutinous rice cultivars.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.1
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• pp.71-76
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• 2000

This study was carried out in order to investigated the degree of expansion, textural and sensory characteristics of Yukwa made from various cultivars of waxy rice, With 5 varieties of waxy rice and a nonwaxy rice, Yukwa were prepared by the standardized method that had been established optimum preparation conditions. Yukwa made from Shinsunchalbyeo and Whasunchal showed lower degree of expansion than Hangangchalbyeo and IR 29, but showed higher crispness and softer texture among tested waxy rice cultivars. Sensory characteristics of these cultivars showed high score in flavor, crispness and preference. Whasunchalbyeo and Shinsunchalbyeo were appropriate varieties for Yukwa preparation and they were both short grain in length/width. Whasunchalbyeo has the highest score of water uptake and reducing sugar content in Key word.

• Journal of Photoscience
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• v.1 no.2
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• pp.135-141
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• 1994

Elevated near-UV radiation, containing a large amount of UV-B and a small amount of UV-C, inhibited the development of leaves and tillers, the increase in biomass production, the elongation of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Elevated UV-B radiation filtered through cellulose diacetate film or UV-31 cut filter (transmission down to 290 nm) similarly suppressed each growth component above. Near-UV radiation-caused injuries were alleviated either by elevated CO$_2$ atmosphere or by exposure to high irradiance-visible radiation. On the basis of these findings, we examined cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes ( aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups. It was shown that .various cultivars having different sensitivities to the effects of near-UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to near-UV radiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of near-UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultivars are cultivated. From the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F$_2$ plants generated by reciprocally crossing Sasanishiki and Norin 1 and F$_3$ lines generated by self-fertilizing F$_2$ plants, it was evident that the resistance to the inhibitory effects of elevated near-UV radiation in these rice plants was controlled by recessive polygenes.

• Journal of the Korean Society of Food Culture
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• v.37 no.6
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• pp.510-518
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• 2022

This study compares the quality characteristics of Jeung-pyun prepared by supplementing with rice mash of various cultivars. Results showed high contents of crude protein and crude ash in Saeilmi. The highest and lowest amylose contents were obtained in Goami4 and Baekjinju, respectively. Saeilmi had the highest water absorption index (WAI) of rice flour, whereas the highest water-soluble index (WSI) was obtained in Baekokchal. Maximum viscosity, minimum viscosity, and breakdown were high in Baekjinju, and high cooling viscosity and setback levels were determined in Goami4. The sugar content, total free sugar, and pH of the rice mash were highest in Baekjinju. The highest volume of Jeung-pyun was obtained with Saeilmi supplementation, whereas the specific volume was highest in Baekokchal. Evaluation of L, a, and b color values of Jeung-pyun revealed the maximum L value in Saeilmi, a value in Goami4, and b value in Baekjinju. The physical properties of Jeung-pyun were lower in all supplemented groups compared to the control group for hardness, adhesiveness, and chewiness. The lowest chewiness was obtained in Baekokchal-supplemented Jeung-pyun. We conclude that supplementation with different varieties of rice affects the quality characteristics of Jeung-pyun, which are important factors for manufacturing processed foods.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.355-363
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• 2018

This study was conducted to investigate suitable rice cultivars for various rice based cropping systems in a paddy field in the Yeongnam plain area. Thirteen rice cultivars (5 early, 3 medium and 5 mid-late maturing cultivars) and three transplanting dates (June 5, June 25 and July 5) were evaluated in this study. The mid-late and early maturing cultivars for the July 5 and June 25 transplanting headed before August 30 which is the safe heading date in the Yeongnam plain area, ranging from Aug. 26 - 28 and Aug. 18 - 23, respectively. The safe harvest time of rice for double and triple cropping systems should be before the middle of October for the cultivation of the succeeding winter crops. The rice yield was the highest for the June 5 transplanting regardless of the rice cultivars, and it gradually decreased as the transplanting date was delayed from June 5 to July 5 due to a decrease in the spikelet numbers per panicle number and in the ripened grain rate. In contrast, the other yield parameters that include the panicle number per $m^2$, the 1,000-brown rice weight, and the ripened grain ratio were not significantly affected. The result indicates that based on the milled rice, heading time and harvest time, a medium maturing cultivar (Haiami and Samdeog) would be applicable to a winter barley/wheat, garlic/onion-summer rice double cropping, while a mid-late cultivar (Saeilmi, Saenuri and Hyunpoom) would be suitable for a spring potato/waxy corn-summer rice double cropping in the Yeongnam plain area. On the other hand, an early maturing cultivar (Unkwang, Jokwang and Haedamssal) would be preferable for a triple cropping because of the short growth period of rice.

• The Plant Pathology Journal
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• v.16 no.2
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• pp.105-109
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• 2000

The Pi-b is the rice gene conferring race specific resistance to the blast fungus Magnaporthe grisea race having a corresponding avirulence gene, AVR-Pi-b. All resistant cultivars have two copies of the Pi-b gene, but susceptible cultivars have a single copy of the gene. About 1 Kbp insertion sequence was detected in the open reading frame of the Pi-b gene from the susceptible cv. Nipponbare. The nature of insertion sequence was identified as a solo long terminal repeat (LTR) of new rice Tyl-copia-like retrotransposon. LTR was widely distributed in the rice genome. Various types of different patterns of restriction fragment length polymorphism of LTR were detected in indica cultivars, whereas a single type was detected from japonica cultivars. The insertion of LTR sequence in the Pi-b gene in the susceptible cultivar suggested that retrotransposon-mediated insertional mutation might played an important role in the resistance breakdown as well as evolution of resistance genes in rice.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.223-226
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• 2008

Seedlings of two rice cultivars i.e. cv. Daesanbyeo and cv. Dongjinbyeo were analyzed for growth and endogenous gibberellins (GAs) in response to nitrogen nutrition applied in the forms of $KNO_3$, $(NH_4)_2SO_4$ and $NH_4NO_3$. All the growth parameters showed an increase in N applied treatments and their magnitudes of increase were different depending on different nitrogen fertilizer forms. The endogenous GAs contents were increased with N application but differentially affected by various N-forms in both rice cultivars. In cv. Daesanbyeo, maximum amount of bioactive $GA_1$ was recorded for $(NH_4)_2SO_4$, while maximum amount of bioactive $GA_1$ in cv. Dongjinbyeo was observed in $NH_4NO_3$ applied treatments. In both rice cultivars, $KNO_3$ applied rice plants contained least $GA_1$ contents. Also, $GA_{19}$ was the most abundant GA found in rice seedlings whereas $GA_4$ was absent at seedling stage. Our study indicated that different rice cultivars showed different responses for the same fertilizer depending upon the response potential of each cultivar and the pertinent physiological responses to changes of endogenous GAs in rice cultivars, which were comparatively lesser in magnitude.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.65-70
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• 2002

This study was conducted to investigate allelopathic potential of various crosses of rice cultivars using their inhibitory effect on barnyardgrass growth under field conditions, and to determine PAL activity and phenolic compounds involved in phenylpropanoid pathway from selected crosses of rice cultivars. Under field conditions, Kouketsumochi, Woo co chin yu possessed higher allelopathic potential inhibiting over 90% of barnyardgrass growth. Crosses of Kouketsumochi/Woo co chin yu, Dongjinbeyo/Kouketsumochi, Dongjinbeyo/Woo co chin yu showed over 80% inhibitory effects on barnyardgrass growth. The highest PAL activity, $63.46{\mu}kats/kg$ proteins was detected in Kouketsumochi which is the most important enzyme in phenylpropanoid pathway and also higher PAL activity in crosses with Kouketsumochi. Content of cinnamate was $2.64{\mu}g/g$ f.w. in Kouketsumochi which was 2 to 5 times higher than other rice cultivars tested, indicating that higher PAL activity resulted in more cinnamate. The similar trends in cinnamate content and PAL activity were observed in crosses of rice cultivars with Kouketsumochi.

• Journal of Life Science
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• v.7 no.4
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• pp.347-354
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• 1997

Some attempts were made to investigate the gentic characteristics of the brown planthopper(BPH), Nilaparvata lugens Sta${\aa}$l, biotypes. In terms of egg and nymphal periods, egg hatcgability, emergence ratio, and population change of BPH and plant damage of rice cultivars by the infestation of BPH biotypes and their hybrid progenies in field conditions. The egg and nymphal periods of the three of BPH biotypes and their hybrid progenies on Dongjinbyeo with no resistance gene were shorter than on rice cultivars with resistance gene. But the periods of biotype-2(♀) X 2(♂) (E) on Samgangbyeo with Bph-1 gene and biotype-3(♀) X 3(♂)(I) on Mirying 63 with bph-2 gene were as short as on Dongjinbyeo. The egg hatchability and emergence ratio of the three Bph biotypes and their hybrid progenies on Dongjinbyeo were higher than on the other rice cultivars, and those of E on Samgangbyeo and I on Miryang 63 were as high as on Dongjinbyeo. In rice paddy field, biotype-1(♀) X 1(♂)(A)$\sim$I infested on Dongjinbyeo, E onSamgangbyeo, and I on Miryang 63 were increased their population densities remarkably in next generation. Dongjinbyeo infested by A$\sim$I, and Myryang 63 infested by I were hopperburned at 60 days after infestation and had a damage rating of 0.9. But Samgangbyeo infested by E was no hopperburn(damage rating: 7.3) though it showed high BPH population at 60 days after infestation.