• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.5
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• pp.405-412
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• 1993

This experiment was conducted to investigate the effects of water depths on seedling stand and early growth of califonia rice varieties, S201, M202, A301, Italico livorno and Korean variety, Hwaseongbyeo, and barnyardgrass (Echinochloa crus-galli) The coleoptile length of rice was longer with deep water depth while for the radicle length shorten. As water depth was increased, the percentage of seedling stand were decreased slightly in rice, while sharply increased in barnyardgrass. Plant height of rice with increasing water depth were longer, whereas that of barnyardgrass reduced significantly with weaker. Tiller number of rice and barnyardgrass were significantly reduced as water depth increased. Dry matter weight and healthy score of rice seedling at 35DAS were highest in 7.5cm water depth followed saturated moisture, 15, and 22.5cm water depth, while for barnyardgrass those were especially negatively affected by deep water depth. These results showed that the seedling stand and early growth of barnyardgrass was highly suppressed by deeper water levels compared with rice. Rice cultivars which are showes growth characteristics in deeper water levels at early growth stage were Italico livorno and S201 in Japonica / Indica.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.1
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• pp.22-29
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• 2001

In Korean high yielding varieties developed by crosses between indica and japonica rice, the most limiting factor for yield may be attributed to the less number of the tillers in the unit area. The goals of this study is to find out the effect of the temperature factors as well as cultural practices on the development and increase of tillers of Dasanbyeo, the high yielding indica crossed japonica cultivar. The effect of temperature was examined under controlled phytotron condition with 6 levels of temperature, 15, 17, 19, 22, 24 and 26$^{\circ}C$, respectively, For the experiment, the leading japonica variety in Korea, Hwaseongbyeo, was used for the check cultivar for the comparison with Dasanbyeo. The high temperature also accelerated the initiation and termination of tiller development. The cultivar difference in the speed of tiller development was observed, for example, more rapid development of tiller in Dasanbyeo than in Hwaseongbyeo was observed at the high temperature range of 24-26$^{\circ}C$, while the vice versa phenomena was observed at lower temperature range of 17-22$^{\circ}C$. The first secondary tiller of Dasanbyeo was observed on the 16, 17, 23, 27 and 38 days after transplanting (DAT) at 26$^{\circ}C$, 24$^{\circ}C$, 22$^{\circ}C$, 19$^{\circ}C$, and 17$^{\circ}C$, respectively. Those of Hwaseongbyeo was 19-22, and 26 DAT at 19-26$^{\circ}C$ and 17$^{\circ}C$, respectively. The last effective tiller of Dasanbyeo was observed on 27-33 DAT for the primary tiller, 20-41 DAT for the secondary tiller. Those of Hwaseongbyeo were 23-40 DAT for primary tiller, and 24-40 DAT for the secondary tiller, and 24-40 DAT for the secondary tiller.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.463-467
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• 2004

This study was carried out to estimate of leaf area index (LAI) rapidly using plant canopy analyzer, comparing with specific leaf area (SLA) and leaf area ratio (LAR) in rice from 2001 to 2002 at Honam Agricultural Research Institute in Iksan Korea. The relationship between LAI values taken by plant canopy analyzer and by leaf area meter showed high correlation at each growth stages of rice. LAIs obtained by plant canopy analyzer were highly correlated with that by leaf area meter which were the highest in Dongjinbyeo and the lowest in Hapcheon1. Specific leaf area (SLA) of all rice cultivars were tend to decrease remarkably with the progress of growth stage. It was found that the SLA of Dasanbyeo was the highest and that of Hapcheon1 was the lowest among rice cultivars tested. Leaf area ratios (LARs) was also decreased with the progress of growth stage.

• Research in Plant Disease
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• v.23 no.3
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• pp.249-255
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• 2017

The rice blast fungus is a representative model phytopathogenic fungus in which Gene-for-Gene interaction with host rice is applicable. After 1980, eight differential varieties have been constructed and classified to analyze the race of rice blast isolates in Korea. However, since there is limited information about the genetic background of rice blast resistance genes within the Korean differentials, scientific analysis on the emergence of new race or resistance break down was difficult. Recently, a differential system has been developed using monogenic resistance lines to understand the interactions of pathogen race and rice resistance genes. In this study, a total of 50 isolates were selected from four different races isolated in Korea, and they were inoculated into monogenic lines. As a result, the isolates in the same race classified by the Korean differential system reacted differently in single monogenic lines. This suggests that the isolates categorized as the same race group contains different avirulence genes and furthermore, it is presumed that the Korean differential system is difficult to provide useful information for breeding program. For this reason, introduction of differential system using monogenic resistance lines is required in addition to the current system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.467-473
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• 2010

The objectives of this study were to determine various bio-active components from some brown rice and milled rice of some cultivars, as well as to assess their contribution to the radical scavenging linked-antioxidant activity. DPPH or ABTS radical scavenging activities, and reducing power have been used to investigate the relative antioxidant activities of 70% ethanol extracts. The contents of total polyphenol, total flavonoid, $\gamma$-oryzanol, and vitamin E in the extracts were also measured by spectrophotometric methods or HPLC. The antioxidant components and antioxidant activities of 70% ethanol extracts from brown rice were higher than those from milled rice. In addition, our results showed that the high level of antioxidant compounds was found in brown rice of Hongjinju, and the antioxidant activities of the 70% ethanol extracts from pigmented brown rices, such as Hongjinju and Heugkwang, were comparably higher than the others.

• Proceedings of the Korean Society of Crop Science Conference
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• 1991.05a
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• pp.52-53
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• 1991

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.146-156
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• 1988

This study was carried out to investigate the change of endosperm substance and seedling growth in rice seedlings for machine transplanting with use of two rice varieties, which Samgangbyeo (Indica${\times}$Japonica) and Dogjinbyeo (Japonica) were sown on May 8 with five levels of seeding density. 1. The total dry matter weight, leaf area, length of the longest root, number and length of new roots were negatively correlated with seeding density, and the plant height had the similar tendency to them from 20 days after sowing(DAS). 2. The rooting ability was negatively correlated with seeding density and decreased from 35 DAS in Dongjinbyeo. 3. The endosperm substance were exhausted at 25 to 30 DAS in Samgangbyeo and at 25 DAS in Dongjinbyeo. 4. The leaf area was more useful than the ratio of plant height to dry matter weight for judging the constitution of seedlings. 5. The reducing sugar contents in the endosperm were the greatest among parts of rice seedlings followed by leaf and root. The contents in leaf, root and endosperm reached maximal at 10 DAS, and varied with plant parts, seedling growth and varieties in different levels of seeding density. 6. The protein contents in leaf and root of rice seedlings became decreased with seedling growth., and were minimal values at 15 DAS. The content in endosperm was decreased soon after seeding, and minimal at 4 DAS with showing some fluctuation of protein content after then.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.182-188
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• 1997

The study was carried out to determine an optimum concentration of plant growth regulators(ABA and kinetin) on reducing NaCl toxicity during germination in rice. Plant height of a japonica cultivar Ilpumbyeo in ABA 10$^{-5}$ M was increased, while all treatments of kinetin had no clear effects on increasing the plant height. However, other rice cultivars showed slightly different reaction by PGRs compared with Ilpumbyeo. Germination rate of four rice cultivars was ranged from 53.1 to 58.2％ in NaCl 1.3％. All treatments of kinetin accelerated germination rate of tested rice cultivars except Dasanbyeo compared with NaCl 1.3％ treatment. The higher concentration of ABA and kinetin treatment induced the higher starch content, and while the lower concentration of two plant growth regulators induced the higher sugar content in all four rice cultivars. The free proline content of rice seedlings was highest in Ilpumbyeo among the tested cultivars under NaCl 1.3％ treatment.

• Korean journal of applied entomology
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• v.17 no.1 s.34
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• pp.53-63
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• 1978

The object of this study is to clarify the varietal resistance to green leaf-and planthoppers and to evaluate the nature of the resistance to the insects in connection with the antibiosis. This study investigated the reaction of the 46 rice varieties to insects including recommended varieties of Korea. At seedling stage they were infested with second or third instar nymphs. The results were as follows. 1. The body weight of brown planthopper was increased more than 3 times on susceptible rice variety Mankyung at 15 days after infestation but only 2 times on resistant mudgo. 2. The mortaliy of the brown planthopper was significantly different between resistant and susceptible rice plant, showing 74 percents in resistant Mudgo while 31.2 percents in susceptible Mankyung at 15 days after caging. 3. Most of the rice varieties tested showed highly susceptible reaction to brown planthopper except Mudgo, KR 108-243-1 and HR 529-41-3-2 as resistant varieties, and Akamochi, Satominori, IR 24 and IR 8 as moderately susceptible ones. 4. In the test of varietal resistance to white-backed planthhopper, Mudgo, KR 108-243-1, KR 109-154-2 and HR 529-45-2 and HR 529-45-3-2 were resistant, and Suweon #82, Tongil, IR 8, Palkeum, Iri #309, Hokwang and Chukoku #31 were moderatly susceptible. 5. Most of the varieties tested were observed as highly resistant to green rice leafhopper, but Tongil, Suweon 82, IR 24, Milsung and Chukoku #31 were moderatly susceptible. 6. The new bred lines HR 108-243-1 are multi-resistant to brown planthopper, green rice leafhopper and White-backed planthopper, and some others showed moderate susceptibility.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.255-263
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• 2020

In this study, we evaluated the salinity tolerance of five forage rice cultivars (Mogwoo, Mogyang, Miwoo, Jowoo, and Yeongwoo) with respect to germination, seedling growth, productivity, and feed values in a reclaimed paddy field in Muan, Korea. We found that the cultivars Mogwoo, Miwoo, Jowoo, and Yeongwoo showed normal germination and seedling growth, even at saline concentrations of between 0.1% and 0.5%, whereas in contrast, there were significant reductions in the germination and seedling growth of Mokyang with an increase in salt concentration. Among the five cultivars assessed, the seedling growth of Mogwoo and Yeongwoo was relatively higher at different salt concentrations in hydroponic and sand cultivation. Furthermore, cultivation of the five cultivars in the reclaimed paddy field with an initial salt concentration of 0.3% revealed that Yeongwoo was relatively superior in terms of yield and feed value. In conclusion, the germination and early growth of Yeongwoo were relatively good at high salt concentrations, and the yield and forage value of this cultivar in a reclaimed paddy field were also relatively superior to those of the other assessed varieties.