• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1383-1388
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• 2001

To explore the factors restricting animal performance in relation to sward structure under a strip-grazing system, measurements of sward factors, herbage intake and milk production at 3 levels of herbage allowance were made on perennial ryegrass (Latium perenne L.) sward for 3 experimental periods. About 29%, 36% and 52% of the biomass offered was removed by grazing in high $(42kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$, medium $(30kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ and low $(18kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ herbage allowance plots. Live leaf material was much more affected by grazing under different herbage allowance levels than dead material or leaf sheath. Grazing with a low herbage allowance decreased the proportion of live lamina by 93% and live lamina density by 96% before grazing. The density of dead material plus sheath was decreased by 17% after grazing at a low allowance, while it slightly increased or remained constant in the plots applied with high and medium allowances, respectively. The highly significant (p<0.01) correlations between herbage allowance and proportion (r=0.94) and density (r=0.91) of live lamina in residual sward after grazing were observed. Daily herbage intakes in the plots with high and medium levels of herbage allowance were not significantly different at $15.3kg\;OM{\cdot}head^{-1}$ in average, whereas with low level it decreased to $13.9kg\;OM{\cdot}head^{-1}$. Daily milk production was significantly (p<0.05) declined from $22.3kg{\cdot}head^{-1}$ (at high herbage allowance) to $19.7kg{\cdot}head^{-1}$ (at low herbage allowance). The data obtained clearly indicated that herbage intake and milk production were highly affected by the characteristics of residual sward, which were closely related to the level of herbage allowance.

• KSBB Journal
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• v.9 no.3
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• pp.319-324
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• 1994

A biosensor for the measurement of malate has been constructed by the sodium-alginate immobilized bundle sheath cell tissue of corn leaf containing malate dehydrogenase (decarboxylating) (EC 1. 1. 1. 40) on the CO2 gas-sensing electrode. The proposed tissue sensor had the linear in the range of malate concentration $5.5{\times}10^{-5}M∼2.5{\times}10^{-2}M$ with a slope of 53.5 mV/decade in 0.02M Tris-HCl buffer solution at optimum pH 8.0, and $25^{\circ}C$. A response time was 16∼18min. The present L-malate sensing tissue sensor is stable for more than one week. At pH 7.4, Km value was $0.6{\times}10^{-5}M$. The various kinds of salt did not effect the signal of malate tissue biosensor as the inhibitor. We can measure the malate by the CO2 electrode at the pH=8.0. Thus, the proposed tissue sensor will be useful for the measurement of malate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.296-301
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• 1999

The concerns on the crop damage by ultraviolet (UV) radiations is increasing owing to the decrease of their absorbing stratospheric ozone in the tropospheric. Cultivar differences on early growth of UV radiation among five Korean rice cultivars, four japonica types and one Tongil type (indica-japonica cross hybrid), were studied. Pot-seeded rice plants were grown under four different radiation conditions, i.e., visible radiation only, visible radiation with supplemented with high or low dose of UV-B (280~320 nm in wavelength) and UV-C (less than 280 nm in wavelength). The inhibitory degree on plant height, shoot and root weight and length of leaf blade and leaf sheath were determined at 40 days after seeding. UV-C showed the most severe inhibitory effect on the degree of biomass gain and leaf growth in most cultivars examined, followed by high UV-B and low UV-B. Among the cultivars used, the Kuemobyeo was the most sensitive cultivar and had not repair or showed resistance ability to continued irradiation of UV radiation. However, Janganbyeo and Jaekeon showed different responses that the elongation of leaf blades was promoted on 2nd and 3rd leaves and inhibited on 4th and 5th leaves but this inhibitory degree was reduced on 6 th and 7th leaves. Such tendency on leaf growth means that both cultivars had low sensitivity and most resistant ability to continued irradiation of UV radiation. While Tongil showed different response to enhanced UV radiation, ie., low UV-B promoted leaf growth but the inhibitory was severely increased by continued irradiation of high UV-B and UV-C, which means that Tongil had high threshold of UV radiation for response as an inhibitory light of plant growth. The results of this study indicate that the differences on sensitivity or resistant to the effects of UV radiation were existed among Korean rice cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.216-222
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• 1994

Experiments were conducted in the research field of the former Wheat and Barley Research with three barley cultivars, Olbori, kangbori and Suwon 18, which show different growth characteristics. Relationships between the degree of grain filling and the functions of photosynthetic organs in grain growth post-anthesis were investigated by removal treatment of awns and leaves, Stems and leaf sheath contributed to final grain weight invariably with cultivars by 79.2∼81.4%. while the contribution rate of awns and leaf blades varied by different cultivars, Awns contributed by 11.6∼13.8% in 'Olbori' and 'Kangbori', and 5.4% in 'Suwon 18', Contribution of leaf blades was 15.4% for 'Suwon 18', and 4.8∼8.1% for other cultivars, Of leaf blades upper ones showed a higher contribution rate, Early-maturing cultivars which maintain leaf greenness to the late phase of grain growth or awned cultivars were considered advantageous in grain filling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.121-125
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• 2004

In plants, nitrogen is the major component for growth and development. Leaf growth is based on the division, elongation and maturation of cells, which are used for making of epidermis, mesophyll, bundle sheath, xylem, phloem and so on. Dynamics of these tissues with respect to nitrogen are required for better understanding. This experiment was conducted to evaluate effect of nitrogen on the elongation of epidermal and guard cell of two rice (Oryza sativa L.) varieties, Seoanbyeo and Dasanbyeo on May 2000 at Chungbuk national university in Cheongju. After transplaning the 20-day-old seedlings into a/5000 pots, the main characteristics related with cell elongation were investigated and evaluated. A maximum. leaf length reached at 7 or 8 days after emerging from the collar, and also the leaf elongation rates were greatly affected by the increase of N application rate. The initial and final cell length were about $17\mu\textrm{m}$ and $130\mu\textrm{m}$, respectively. Cell divisions occurred within 1.0mm from leaf base. With die higher nitrogen application rate of 22 kg-N $10\textrm{a}^{-1}$, cell division per hour was greater 1.5 to 1.9 and 1.2 to 1.3 fold as compared to the N application rate of 0 and 11 kg-N $10\textrm{a}^{-1}$, respectively. Cell enlargement of epidermal and guard cell under higher N application rate (22kg-N $10\textrm{a}^{-1}$) was finished within about 20 (Seoanbyeo) and 15 hours (Dasanbyeo), while it took much time, about 30 hours.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.186-194
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• 2006

Nitrogen dynamics of Seagrass Zostera marina were investigated in both Dongdae Bay and Ojiri from March to August, 2004. All seagrass samples were separated into four fractions such as leaves (new and adult), sheath and rhizome in order to understand temporal variations of nitrogen content in different fractions of Zostera marina. There are temporal variations of shoot production rates and total nitrogen contents in their different fractions at both study areas. Leaf production were almost 4 to 5 fold higher in summer than in winter. The irradiance is the primary factor controlling the leaf production of Zostera marina in both sites although water temperature also influence its productivity. Nitrogen contents of leaves were overall low in summer than in winter, but nitrogen content of rhizome increased during the summer season. In addition, nitrogen contents of new leaves were mostly higher than adult leaves in spite of lower nitrogen content of new and adult leaves in high productivity period. This result suggests that Zostera marina seems to have significant translocation ability of nitrogen in a shoot. The nitrogen content of leaf tissue may reflect nutritional nitrogen availability.

• Journal of Plant Biology
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• v.37 no.1
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• pp.53-67
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• 1994

The opal phytolith types in Oryza sativa L. were examined with light and scanning electron microscope, and we suggested the standard tenninoligies based on original cells of the phytoliths in situ. The distinctive fonus of opal phytoliths were observed in all plant parts such as leaf blade, leaf sheath, culm, root, glume, lemma, and palea. The phytolith fonus originated from long cell, short cell, and dennal appendages were different from part to part. The opal phytoliths derived from the long cells showed the most various form: twelve types were identified based on side wall shape. The results showed that the leaf blade did include almost all types of opal phytolith observed in the other parts of rice.f rice.

• Applied Microscopy
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• v.33 no.3
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• pp.233-241
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• 2003

Patterns of tannin accumulation in leaves of C-4 Euphorbia maculata have been examined using electron microscopy. Tannins, which are secondary metabolite phenolic compounds, were found to be deposited conspicuously in vacuoles of certain tissues regardless of their stage in development. However, patterns of deposit accumulation were distinguishable by their cell type during leaf differentiation. The deposits appeared most concentrated in the concentric bundle sheath cells enclosing veins, while little or no density was detected mostly in the mesophyll cells close to the epidermis. An ultrastructural study revealed that the deposits were restricted to the vacuoles at an early stage of leaf development; during which the vacuoles were almost completely filled with the tanniferous substances. The deposits themselves took different forms ranging from granules to huge globules while expanding leaf blade. As the leaf matured, the deposits accumulated either centripetally adjacent to the inner tangential tonoplast or by penetration into the cytoplasm amongst various cellular organelles, resulting in an extremely dense cytoplasm. Electron micrographs frequently showed the delineation of each organelle by the presence of dense deposits within the cytoplasm. Some large depository vacuoles filled with tannins had a corrugated appearance on the sectioned surface. The pattern and potential role of the deposits have been discussed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.2
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• pp.93-100
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• 2012

We examined the contents of amino acids to provide the basic data for the utilization of white panicled rice (Oryza sativa L., WPR) cultured in reclaimed paddy field of Bigumdo of Korea in 2011. WPR used in this study were collected in 1000 ha of reclaimed paddy field of Bigumdo. Crude protein contents of whole rice have the highest in leaf blade, followed by whole grain, leaf sheath and stem. The contents of total amino acids showed the highest trend in region received the most severe damage, but the lowest trend in region of normal growth. The content of glutamic acid was the highest among amino acids in leaf blade, whole grain, leaf sheath and stem collected in all regions, but the content of methionine was the lowest. Therefore, the contents of amino acids showed a similar level between the region occurred WPR and the region of normal growth. Further research on the nutritional aspects of forage must be performed because nutritive values of WPR were influenced by the degree of damage of WPR.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.54-63
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• 1996

This study was conducted to investigate the anatomical and ultrastructural responses of the oxyfluorfen-tolerant and -susceptible rice cultivars with barnyardgrass, a typical susceptible weed by oxyfluorfen and the herbicides having similar mode of action treatment. After the treatment of $10^{-5}M$ oxyfluorfen, the tolerant rice cultivars no showed the structural damage of leaf surface, but the susceptible rice cultivate was damaged in the wax and the susceptible barnyardgrass was even destroyed in the tissue irregularly. Also in the susceptible rice cultivars and barnyardgrass the thickness of leaf blade was greatly decreased. The anatomical change was not observed in the tolerant rice cultivars but epidermal cells, mesophyll cells and bundle sheath cells were badly broken in the susceptible rice cultivars and barnyardgrass and especially after 24 hours of the treatment the structure of susceptible rice cultivars was completely disintegrated. The irregularity of chloroplast shape and the distortion of chloroplast envelope were generally observed and the starch tended to decrease by oxyfluorfen treatment regardless of rice cultivars. Such a structural damage were appeared more badly in the susceptible rice cultivars and bamyardgrass than in the tolerant rice cultivars. By the treatment of diphenyl ether herbicides, the thickness of leaf blade greatly reduced in the order of oxyfluorfen > acifluorfen > bifenox > oxadiazon, and the susceptible rice cultivars showed more reduction than the tolerant rice cultivars. Especially, the susceptible rice cultivars showed that the leaf structure was badly broken down with damage epidermal cells and bundle sheath cells.