• Title/Summary/Keyword: Leaf diffusive resistance

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Stomatal Control and Strategy Segregation to Drought Stress in Young Trees of Several Oak Species (수종 참나무속 유식물의 건조스트레스에 대한 기공저항의 조절과 전략의 분화)

  • 김종욱;김준호
    • The Korean Journal of Ecology
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    • v.17 no.3
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    • pp.241-249
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    • 1994
  • Leaf diffusive resistance (LDR), stomatal density, length of guard cell and hair density of leaves of 6 oak species were determined under withdrawal of water, and their strategies of drought stress were analyzed by principal component analysis. LDR of Quercus acutissima, Q. aliena and Q. serrata increased earlier than those of the other species at high leaf water potential $({\Psi}_{leaf})$ or low water saturation deficit (WSD), which was an avoidance mechanism reducing damage by water stress. Q. variabilis with low stomatal density, small stomatal size and high hair density had avoidance mechanisms increasing LDR at high $({\Psi}_{leaf})$ However, Q. mongolica and Q. dentata increased LDR at low $({\Psi}_{leaf})$ as xeric species do. Results from principal component analysis on the 15 variables related to strategies of drought stress indicated that the 6 oak species were divided into 2 groups: (1) Q. acutissima, Q. aliena and Q. serrata as mesic habitat species and (2) Q. variabilis, Q. mongolica and Q. dentata as xeric habitat species. Among three xeric species Q. acutissima differed from the other two species in the drought strategies such as high hair density, low stornatal density, high leaf area ratio, stomatal closing at low $({\Psi}_{leaf})$ and small cell wall elasticity. The results could reasonably explain their drought strategies in natural habitat.

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Transpiration Modelling and Verification in Greenhouse Tomato (온실재배 토마토의 증산모델 개발 및 검증)

  • 이변우
    • Journal of Bio-Environment Control
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    • v.6 no.3
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    • pp.205-215
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    • 1997
  • An accurate transpiration model for greenhouse tomato crop, which is liable to transpiration depression and yield loss because of low solar radiation and high humidity, could be an efficient tool for the optimum control of greenhouse climate and for the optimization of Irrigation scheduling. The purpose of this study was to develop transpiration model of greenhouse tomato and to carry out the experimental verification. The formulas to calculate the canopy transpiration and temperature simultaneously were derived from the energy balance of canopy. Transpiration and microclimate variables such as net radiation, solar radiation, humidity, canopy and air temperature, etc. were simultaneously measured to estimate parameters of model equations and to verify the suggested model. Leaf boundary layer resistance was calculated as a function of Nusselt number and stomatal diffusive resistance was parameterized by solar radiation and leaf-air vapor pressure deficit. The equation for stomatal diffusive resistance could explain more than 80% of its variation and the calculated stomatal diffusive resistance showed good agreements with the measured values in situations independent of which the constants of the equation were estimated. The canopy net radiation calculated by Stanghellini's model with slight modification agreed well with the measured values. The present transpiration model, into which afore-mentioned component equations were assembled, was found to predict the canopy temperature, instantaneous and daily transpiration with considerable accuracy in greenhouse climates.

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Diurnal Changes in Stomatal Diffusion Resistance and Distribution of Stomata on Different Leaf Positions in Barley and Wheat (맥류의 기공확산저항의 일중변화와 입위별 기공의 분포)

  • 이호진;윤진일;이광회
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.26 no.1
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    • pp.45-50
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    • 1981
  • Diurnal changes in leaf stomatal resistances were measured on leaf positions and both surfaces to investigate the stomatal response to irradiance in wheat, var. Chokwang and barley, var. Dongbori 1. Stomatal frequency and size were also determined to explain the control mechanism of gas exchanges in two species. The leaf diffusive resistances of two species decreased, as the sun rose, to minimum at 10 to 11 o'clock a.m. and increased gradually in the afternoon, even faster at sunset. As the adaxial irradiance increased, stomatal resistances decreased sensitively in the range of 30uEm$^{-2}$ㆍsec$^{-1}$ to 150uEm$^{-2}$ㆍsec$^{-1}$ quantum flux density. The stomatal opening of the abaxial surface began at lower irradiance and was completed earlier than the adaxial surface. The adaxial irradiances decreased in order of leaf position, flag, the 2nd, the 3rd leaf, and the stomatal resistances increased in the same order. Even under the same irradiance, the stomatal resistance of lower leaves were higher than those of upper leaves. The stomatal frequencies of lower leaves were less, but the stomatal size was greater than those of upper leaves. Consequently, the relative leaf area occupied by stomatal pores were constant among leaf positions in two species.

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Antioxidant Enzyme, Chlorophyll Contents and Stomatal Changes of Five Tree Species under Ozone Stress (저농도 오존처리에 따른 다섯 가지 유묘의 기공 변화, 엽록소 함량 및 항산화 효소 활성)

  • Ryang, Soo Zin;Woo, Su Young;Je, Sun Mi
    • Journal of Korean Society of Forest Science
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    • v.96 no.4
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    • pp.470-476
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    • 2007
  • This study is conducted to identify responses of plants to low $O_3$ concentration, Five species, Liriodendron tulipifera, Cornus officinalis, Ginkgoba biloba, Zelkova serrata, and Acer palmatum, were exposed to low ozone concentration from June 9 to July 8 in the phytotron, We measured chlorophyll contents, leaf diffusion resistance, leaf transpiration, and antioxidant enzyme activities; ascorbate peroxidase(APX), Especially, Liriodendron tulipifera and Cornus officinalis showed sensitive responses to ozone treatment as visible injuries, while other four species relatively showed tolerant responses. However, we noticed that almost all species under ozone treatment were lower physiological activities such as chlorophyll contents, leaf diffusion resistance, leaf transpiration, and antioxidant enzyme activities with time even without any visible injury.

Effect of Water Stress at Different Growth Stages on the Growth and Yield of the Transplanted Rice Plants (벼의 생육기별 수분결핍장애가 생육 및 수량에 미치는 영향)

  • 남상용;권용웅;권순국
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.2
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    • pp.31-41
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    • 1986
  • Knowledge of the degree of yield reduction due to water stress at different crop growth stages in rice production is important for rational scheduling of irrigation during periods of insufficient water supply. Previous studies to determine the degree of yield reduction duo to water stress suffered from interruptions by rain during experiment. Also the findings did rot relate the degree of water stress to the soil water potential and water deficit status of rice plants. In this study, two years experiments were conducted using the high yielding rice varieties, an Indica x Japonica (Nampoong) and a Japonica variety(Choochung). These were grown in 1/200$^{\circ}$ plastic pots placed under a rainfall autosensing, sliding clear plastic roof facility to control rainfall interruptions. The results obtained were as follows. 1.The two varieties differed in the growth stage most sensitive to water stress as well as the degree of yield reductions. When rice plants were stressed to the leaf rolling score 4 and soil water potential of about - 20 bar at major crop growth stages which included heading, booting, non-effective tillering, panicle initiation and early tillering stages, the yield reductions in the Indica x Japonica variety were 58%, 34%, 27%, 22%, and 21%, respectively, whereas in the Japonica vairety they were 23%, 36%, 1%, 13% and 22%, respectively. This result show that the recommended drainage during non-effective tillering is valid only for the Japonica variety. Sufficient irrigation at booting, heading and early tillering stages are necessary for both varieties. 2.The two varieties showed visible wilting symptoms when the soil water potential dropped to about - 3.0 bar. The Japonica variety showed more leaf rolling than the Indica X Japonica. However, it had a higher retention of leaf water content and greater stomatal diffusive resistance. When the soil water potential dropped, the Japonica variety showed leaf rolling score (LRS) 1 at 0 soil-5. 0 bar and LRS 2 at 0 soil -6.0 bar while the Indica X Japonica showed LRS 1 at 0 soil - 5.5 bar and LRS 2at 0 Soil - 9.0 bar. The stomatal diffusive resistance was maximum at the second top leaf blade in both varieties at intermediate water stress of 0 soil - 4.5 bar. 3.The number of days that was required for the soil water potential to drop to-3. 0 bar and to - 20.0 bar after drainage of irrigation water from the 20cm deep silty clay loam soil in the pots were 6 and 13 days, respectively for booting stage, and 7 and 11 days, respectively for heading stage, 9 and 12 days, respectively for panicle initiation stage, and 12 and 19 days, respectively for early tillering stage. 4.Water stress during the early tillering stage recorded the longest delay in beading time, the largest reduction in panicle numbers and a substantial yield decrease of 20%. This calls for better water management to ensure the availability of water at this stage, particularly during drought periods. In addition, a reexamination of the conventional inter-drainage practice during the non-effective tillering stage is necessary for the high yielding Indica X Japonica varieties.

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Behaviors of Arsenic in Paddy Soils and Effects of Absorbed Arsenic on Physiological and Ecological Characteristic of Rice Plant;IV. Effect of As content in water on transpiration, stomatal resistance, temperature and humidity in the leaves of rice plant (토양중(土壤中) 비소(砒素)의 행동(行動)과 수도(水稻)의 비소흡수(砒素吸收)에 의(依)한 피해(被害) 생리(生理) 생태(生態)에 관한 연구(硏究);IV. 수경시험(水耕試驗)에서 비소처리(卑小處理)가 수도(水稻)의 증산(蒸散), 기공저항성(氣孔抵抗性) 및 엽(葉)의 온(溫), 습도(濕度)에 미치는 영향(影響))

  • Lee, Min-Hyo;Lim, Soo-Kil-H;Kim, Bok-Young
    • Korean Journal of Environmental Agriculture
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    • v.6 no.2
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    • pp.39-45
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    • 1987
  • A water culture experiment was conducted to investigate the effect of As content in a culture solution on the water status and growth of rice plants. Rice (Oryza sativa L. Line. Iri 316) seeds were germinated in bentonite and cultivated there for 30 days. Rice seedlings were transplanted into 3.5l pots containing the culture solution on May 1, 1985 and allowed to grow without As treatment for one month. Afterwards, they were grown in a culture solution maintaining the final concentration of As, 0, 1, 5, 10 and 15mg/1 renewing in the solution dissolved sodium arsenate at intervals of 3 to 7 days. Plants were cultivated in the green house during the growing period and harvested 60 days after As treatment. The results obtained were as follows: Transpiration of rice plants was decreased with the increase of the As level in the culture solution. Stomatal diffusive resistance and leaf temperature increased with increase of As levels though the humidity and the air flow rate in leaf decreased. Air flow rate, transpiration and stomatal diffusive resistance showed a highly significant correlation with As contents in shoots and roots of rice plants: Espally The air flow rate and transpiration revealed a significantly higher correlation with As contents in the root than that in the shoot, but diffusive resistance showed adverse tendency. High levels of As in the culture solution depressed plant height, no. of tillers, leaf width and dry weight of plant remarkably. Typical symptoms of As toxicity were root discoloration, and necrosis of leaf tips and margins, and leaf rolling during the sunny daytime were also another symptoms.

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Effects of Ca : K Ratios in Nutrient Solution on Photosynthesis, Transpiration, Growth and Incidence of Tipburn in Butterhead and Leaf Lettuce. (배양액내 Ca : K 비율이 상추의 광합성, 증산, 생육 및 tipburn 발생에 미치는 영향)

  • 배종향;이용범;최기영
    • Journal of Bio-Environment Control
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    • v.8 no.1
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    • pp.42-48
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    • 1999
  • This study was executed to see the effects of Ca : K ratios in me.L$^{-1}$ -0:9, 1.5:7.5, 3:6, 4.5:4.5, 6:3 - in the nutrient solution on the photosynthesis, transpiration, growth and incidence of tipburn in butterhead ‘Omega’and Leaf ‘Grand Rapids’lettuce (Lactuca sativa. L) grown in nutrient film technique(NFT). The photosynthesis of both lettuces showed high in the Ca : K ratios of 3:6 and 4.5:4.5 regardless of species. But stomatal resistance of Grand Rapids was higher than that of Omega. The highest transpiration rate of them was shown in the Ca : K ratio of 3:6. The transpiration rate of developing leaves was lower than that of expanded leaves. It was seemed to have relation with incidence of tipbum in the developing leaves. The nutrient solution treatment without Ca developed less growth than that of other treatments, especially growth and development of apical part were inhibited, so that in the both of them incidence of tipburn appeared 100 percent. The incidence of tipburn in Omega appeared 25 percent in the Ca/K ratio of 1.5:7.5, but Grand Rapids did not show it according to the Ca/K ratio in nutrient solution. The highest growth in two species was also shown in the Ca/K ratio of 3:6 except nutrient solution without Ca. This study suggested that the unbalanced ratio of Ca/K affected Ca transport in two species because of the increase of stomatal resistance and diffusive resistance and the decrease of photosynthesis and transpiration.

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Effect of $TO_3$ and $NO_2$ on Net Photosynthesis, Transpiration and Accumulation of Nitrite in Sunflower Leaves

  • Park, Shin-Young;Lee, Sang-Chul
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.3 no.2
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    • pp.121-129
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    • 1999
  • Photosynthesis and transpiration rates were simultaneously measured in attached sunflower leaves(Helianthus annuusL. cv. Russian Mammoth) during exposure to $NO_2$ and $O_3$ to determine the effect of mixed gan on photosynthesis and the stomatal aperture. The application of $O_3$ alone reduced both the net photosynthetic and transpiration rates. An analysis of the $CO_2$ diffusive resistances indicated that the main cause affecting photosynthesis reduction during $O_3$ exposure was not the internal gas phase of the leaf $(rCO_2^{liq})$ but rather the liquid phase or mesophyll diffusive resistance $(rCO_2^{liq})$, suggesting that there is a very concomitant relation between photosynthetic reduction and $rCO_2^{liq}$. The application of NO2 alone caused a marked reduction of the net photosynthesis yet no significant reduction of transpiration, indicating that NO2 affects the $CO_2$ fixation processes with no inluence on the stomatal aperture. A greter reduction in the photosynthesis of sunflower plants was caused by the application of $NO_2$ alone as compared to a combination of $NO_2$ and $O_3$. $NO_2$ alone reduced the photosynthetic rate by 90%, whereas a mixture of NO2 and O3 reduced it by 50%.

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Influence of Short-term Application of Abscisic Acid in Nutrient Solution on Growth and Drought Tolerance of Tomato Seedlings (토마토 육묘과정에서 단기간 ABA처리가 묘소질과 건조내성에 미치는 영향)

  • Kim, Il-Seop;Vu, Ngoc-Thang;Vo, Hoang-Tung;Choi, Ki-Young;Kim, Young Shik
    • Journal of Bio-Environment Control
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    • v.24 no.1
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    • pp.13-20
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    • 2015
  • This study was conducted to evaluate influence of short-term application of abscisic acid (ABA) in nutrient solution on growth and drought tolerance of tomato seedlings. The treatments included four ABA concentrations (0.5, 1, 2, $3mg{\cdot}L^{-1}$) and control (non-treatment) were applied to the nutrient solution in a hydroponic system. On the $5^{th}$ and $10^{th}$ day after growing in the nutrient solution containing ABA, seedlings were transferred to -5 bars of PEG-8000 in a growth chamber to induce water stress. Except for stem diameter and fresh and dry weight of root, there were no statistical differences in other growth parameters among control, 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments. Seedlings growths were strongly inhibited in nutrient solution containing 2 and $3mg{\cdot}L^{-1}$ of ABA. The root growth such as fresh and dry weigh of root, total root surface area, and average root diameter was slightly enhanced in $1mg{\cdot}L^{-1}$ of ABA treatment. The elevation of ABA concentrations in nutrient solution resulted in the decrease in transpiration rate and increase in stomatal diffusive resistance and leaf temperature of tomato seedlings. The initiations of seedling wilting after treating in -5 bars of PEG were delayed from 10 hrs in control to 30 hrs in ABA applied treatments. Additionally, the high percentages of recovered seedlings were observed in 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments after re-irrigation. Therefore, short-term application of $1mg{\cdot}L^{-1}$ of ABA in the nutrient solution stimulated the root growth and drought tolerance of tomato seedlings by delaying the start time of wilting point and enhancing the recovery after re-irrigation.