• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.210-216
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• 1995

Alternaria spp.were predominantly isolated from the abnormal leaf spot lesions of pear cultivars Niitaka and Nijiiseiki. Alternaria isolates from the cultivar Niitaka were not pathogenic to both cultivars, but the isolates from the cultivar Nijiiseiki developed typical lesions of black leaf spots and were identified as A. kikuchiana. However, no typical abnormal leaf spot lesions were produced by the Alternaria isolates. Foliar spray of twelve different agrochemicals including lime sulfur, either alone or in combinations, with 7 times applications from April to July failed to reduced the disease development. Application of 17 different pesticides including fungicides, insecticides and herbicides currently used in pear orchards did not cause leaf injury similar to the abnormal leaf spot. Simulated acid rain of as low as pH 3.0 did not incite any leaf lesions alike the abnormal spot lesions. Mineral contents in the leaves of both cultivars did not differ significantly between the healthy leaves and those with abnormal leaf spots. When cuttings of pear tree were obtained in February from newly emerged twigs of the healthy or the diseased trees of Niitaka and planted in sand in the greenhouse, only those from the diseased trees developed typical leaf lesions of the abnormal spot. These results indicate that abnormal leaf spots are caused by unknown systemic agents in pear trees, rather than by Alternaria spp., chemical injury or acid rain.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.308-308
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• 2017

The low and unstable yield of soybean has been a major problem in Japan. Excess soil moisture conditions are one of the major factors to restrict soybean productivity. More than 80 % of soybean crops are cultivated in converted paddy fields which often have poor drainage. In central and eastern regions of Japan, the early vegetative growth of soybean tends to be restricted by the flooding damage because the early growth period is overlapped with the rainy season. Field observation shows that induced excess water stress in early vegetative stage reduces dry matter production by decreasing intercepted radiation by leaf and radiation use efficiency (RUE) (Bajgain et al., 2015). Therefore, it is necessary to evaluate the responses of soybean growth for excess water conditions to assess these effects on soybean productions. In this study, we aim to modify the soybean crop model (Sinclair et al., 2003) by adding the components of the restriction of leaf area development and RUE for adaptable to excess water conditions. This model was consist of five components, phenological model, leaf area development model, dry matter production model, plant nitrogen model and soil water balance model. The model structures and parameters were estimated from the data obtained from the field experiment in Tsukuba. The excess water effects on the leaf area development were modeled with consideration of decrease of blanch emergence and individual leaf expansion as a function of temperature and ground water level from pot experiments. The nitrogen fixation and nitrogen absorption from soil were assumed to be inhibited by excess water stress and the RUE was assumed to be decreasing according to the decline of leaf nitrogen concentration. The results of the modified model were better agreement with the field observations of the induced excess water stress in paddy field. By coupling the crop model and the ground water level model, it may be possible to assess the impact of excess water conditions for soybean production quantitatively.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.1-5
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• 2007

The Precesses for leaf development in dicotyledonous plants are surprisingly complex, while the mechanism of controlling and coordinating them is poorly understood. To characterize the fundamental features of the leaf development of Arabidopsis, we first attempted to isolate mutants that alter leaf morphology. Here, leaf morphological mutant of Arabidopsis, lanceolatal (lan1) which has small and narrow leaves have isolated and characterized. To clarify the function of LAN1 in organ development, we characterized lan1-7 mutant using an anatomical and genetic approach. The lan1-7 mutant had reduced size of foliage leaves and reduced dimensions of stems. A reduction both in cell size and in cell number was evident at the cellular level in the lan1 mutant, revealing that LAN1 gene appears to affect cell division at an earlier stage and cell elongation throughout the development of leaf primordia. from the analysis of heterogeneous plant with lan1 mutation and 35S-AG transgenic plant, AG gene is revealed to regulate leaf morphology under the control of 35S promoter. Thus, MADS-box gene was revealed to have some relationship to that of LAN1 gene at certain stage in leaf development processes.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.279-285
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• 2023

The demand for the fresh leaf of hooker chive, which is mainly used as functional roots and contains dietary sulfur or saponin, is increasing, but the leaves are only harvested 3-4 times per year under conventional field conditions. A plant factory system with different light qualities or intensities was applied for year-round production of the fresh leaves. Hooker chive (Allium hookeri) roots were hydroponically cultured under the plant factory with a mixture of blue plus red LEDs (Light-Emitting Diodes) and fluorescent lights for 50 weeks. Maximum leaf growth was attained with the 1.5 dS/m EC in the culture medium under the plant factory. The average leaf and shoot numbers of hooker chive grown hydroponically under a mixture of 200 µmol/m²/s LEDs increased by 147% and 140%, respectively compared to those under 100 µmol/m²/s LEDs at the 10th harvest. The leaf length of hooker chive grown under the LEDs treatment with the lowest light intensity significantly increased by 27% compared with the natural light treatment at the 10th harvest. However, there was no significant difference in leaf pigmentation between natural and 200 µmol/m²/s LEDs treatments. Plant factory with the mixture LEDs of blue and red lights can be applied for year-round production of hooker chive fresh leaves to ensure a stable supply of leafy vegetable throughout the year.

• Tribology and Lubricants
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• v.17 no.2
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• pp.97-108
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• 2001

This paper describes the development of performance analysis technique for a leaf-type gas lubricated fail bearing. Stiffness coefficient and frictional damping due to the slip between all contacts of leaves are evaluated for various leaf structures. The fluid film thickness and pressure distribution are computed but it is not considered the elastic deformation by film pressure. The analysis results include the effects that the curvature radius and the length of leaf and the friction coefficient have on the static and dynamic characteristics of the foil bearings.

• Journal of the Korean Society of Food Culture
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• v.29 no.4
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• pp.355-363
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• 2014

The purpose of this study was to investigate the rheological characteristics of medium wheat flour mixed with bamboo leaf and lotus leaf powders. Rheological properties of the mixed flours were tested based on falling number, color, RVA, farinogram, and rheofermentometer analyses. Falling numbers increased with addition of bamboo leaf and lotus leaf powders. The L values of all mixed flours were less than that of control. The 1% mixed flour sample containing bamboo leaf and lotus leaf powders was not significantly different from 3% mixed flour. The a values of the mixed flour decreased as bamboo and lotus powders increased, whereas b values increased. Addition of bamboo leaf and lotus leaf powders to flour reduced peak viscosity, holding strength, and final viscosity. The set back values of mixed wheat flour containing bamboo leaf powder were lower than those of mixed wheat flour containing lotus leaf powder, suggesting that bamboo leaf powder suppressed retrogradation of flour compared to lotus leaf powder. In the farinogram, the water absorption and consistency of the flours containing bamboo and lotus leaf powders increased, whereas development time and stability decreased. The fermentation time of dough with lotus leaf powder was less than that of dough with bamboo leaf powder.

• Journal of Sericultural and Entomological Science
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• v.23 no.2
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• pp.55-58
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• 1982

This survey was carried out at the Sericultural Experiment Station. Suweon to clarify the kinds of leaf rollers damaging mulberry leaves and determine the dominant species of them. The results obtained are as follow: 1. A total of seven species including 2 unrecorded species, Olethreutes hemiplaca MAYRICK. and Olethreutes doubledayana BARRET, were found as mulberry attacking leaf rollers. 2. The dominant species of mulberry leaf rollers in Korea was identified as O. hemiplaca M. followed by Adoxophyes orana B.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.417-425
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• 2012

Salinity stress is one of the most serious factors limiting the productivity of agricultural crops. The aim of this study was to assess inter-cultivar (intraspecific) variation for salinity tolerance in six Korean rapeseed (Brassica napus L.) cultivars at the seedling stage. The effect of three different salinity stress levels (EC 4, 8, and 16 $dS{\cdot}m^{-1}$) on seedlings of six cultivars was investigated through leaf size, leaf dry weight, and leaf chlorosis. At the highest salinity level (16 $dS{\cdot}m^{-1}$), the mean decrease of leaf dry weight in 'Sunmang', 'Tammi', 'Tamla', 'Naehan', 'Youngsan', and 'Halla' was about 56.2, 56.9, 78.4, 79.3, 77.4, and 80.9%, respectively. 'Tammi' and 'Sunmang' showed much less reduction in leaf dry weight than all the other cultivars. In addition, diluted seawater treatments increased the occurrence of leaf chlorosis in six cultivars. At EC 8 and 16 $dS{\cdot}m^{-1}$, 'Naehan', 'Youngsan', and 'Halla' showed a higher level of leaf chlorosis than 'Tammi' 'Sunmang', and 'Tamla'. On the basis of these results, six cultivars were placed into salinity-tolerant and sensitive groups. 'Tammi' and 'Sunmang' were the salinity-tolerant cultivars, while 'Naehan', 'Halla', 'Youngsan', and 'Tamla' were the salinity-sensitive cultivars. 'Tammi' and 'Naehan' rated as the most tolerant and most sensitive cultivar, respectively. To further analyze protein expression profiles in 'Tammi' and 'Naehan', 2-D proteomic analysis was performed using the plants grown under diluted seawater treatments. We identified eight differentially displayed proteins that participate in photosynthesis, carbon assimilation, starch and sucrose metabolism, amino acid metabolism, cold and oxidative stress, and calcium signaling. The differential protein expressions in 'Tammi' and 'Naehan' are likely to correlate with the differential growth responses of both cultivars to salinity stress. These data suggest that 'Tammi' is better adapted to salinity stressed environments than 'Naehan'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.1-5
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• 2000

Leaf area is critical for crop light interception, and thereby has a substantial influence on crop yield. This experiment was conducted to characterize the development of soybean [Glycine max (L.) Merr.] leaf area. Plastochron index and leaf relative growth rate of Jackson was contrasted with the PI416937, which also has demonstrated tolerance to drought. First, plastochron ratio (PR) and plastochron index (PI) were evaluated in greenhouse to compare the leaf growth rate between two genotypes under well-watered condition. There was reasonable constancy of PR between two genotypes. The PR means of Jackson and PI416937 were 0.41 and 0.44, respectively. A fairly smooth increase of PI during vegetative stage was observed. Second, the relative growth rates were graphed against leaf area, normalized with respect to final leaf area, under well-watered and water-deficit conditions. Leaf growth was sustained longer in well-watered condition than water-deficit condition and there was a sizable proportion of leaves which was ceased earlier their growth in water-deficit condition compared to well-watered condition. The leaf relative growth rate of Jackson until leaves had completed at 45% of their growth during water deficit period was higher than that of PI416937.

• Journal of the Korean Society of Food Culture
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• v.23 no.5
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• pp.639-645
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• 2008

The objective of this study was to assess the quality characteristics of morning-rolls containing various levels (0, 4, 8, and 12%) of bamboo leaf powder. The results demonstrated that morning-roll volume decreased with increasing amounts of bamboo leaf powder, and as the bamboo leaf powder content increased, the Hunter's color 'L', 'a' and 'b' values were significantly reduced (p<0.05). For the amylogram characteristics, the addition of bamboo leaf powder to the flour reduced peak viscosity, holding strength, final viscosity, and setback. The results of the sensory evaluation demonstrated that control (0%) and 8% addition of bamboo leaf powder had the best scores in taste, color, flavor, texture, appearance, softness, wetness, residual mouth feel, and overall acceptability. Thus, it appears that by using 8% additions of bamboo leaf powder, the functionality, nutritional composition, taste, color, and flavor of morning-rolls containing bamboo leaf powder can be developed. This result will support the development of better quality bamboo-leaf morning-rolls.