• The Korean Journal of Ecology
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• 제15권1호
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• pp.47-58
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• 1992

This study is to investigate the change of the seasonal patterns of relative water relations parameters by the pressure-volume curves in pinus koraiensis needles. The osmotic potentials at full water saturated(Ψ0, sat) and at incipient plasmolysis(Ψ0, tlp) increased in growing season, while decreased in non-growing season. The maximum bulk modulus of elasticity(Emax), relative water content(RWCTLP), and relativefree water content(FWCtlp) at incipient plasmolysis in non-growing season were higher than these of growing season. The maximum pressure potential(Ψp, max) varied from 1.16 to 2.18MPa, torgor index(TI) varied from 3.1 to 4.7. The osmole number(Ns/dw) and symplastic water (Vo/DW) were variable seasonally. The maximum water content(Vt/DW) and apoplastic water(AW) were relatively high in early growing stage, and then decreased to needle aging. The pressure potential(Ψp) and water potential(Ψ) in winter needles were rapidly decreased with decreasing of relative water content. The matric potential occupied over 10 percent of water potential with less than-2.0 MPa.

• 한국산림과학회지
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• 제63권1호
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• pp.28-34
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• 1984

본연구(本硏究)는 몇 종(種)의 침엽수(針葉樹)의 지엽(枝葉)에 있어서 P-V 곡선법(曲線法)에 의해 얻은 수분특성인자(水分特性因子)와 기공폐쇄작용(氣孔閉鎻作用)과의 관계(關係)를 측정고찰(測定考察)한 것으로 그 결과(結果)는 다음과 같다. 1. P-V 곡선법(曲線法)에 의해 구(求)한 초기원형질리점(初期原形質離點)의 water potential 값과 완전기공폐쇄점(完全氣孔閉鎻點)의 water potential 값은 거의 일치(一致)하였다. 2) 완전기공폐쇄점(完全氣孔閉鎻)는 잣나무 -21 bar(음엽(陰葉) -17 bar), 리기다 -20 bar, 소나무 -22 bar, 일본잎갈나무 -24 bar 전후(前後)에서 일어났다. 상대함수율(相對含水率)로 나타내면 잣나무 85%(음엽(陰葉) 82%), 리기다 77%, 소나무 85%, 일본잎갈나무 70% 전후(前後)에서 완전기공폐쇄(完全氣孔閉鎻)가 일어났다. 3. 초기기공폐쇄(初期氣孔閉鎻)는 잣나무 -14 bar(음엽(陰葉) -12 bar), 리기다 -10 bar, 소나무 -15 bar, 일본잎갈나무 -6 bar 전후(前後)에서 일어났다. 상대함수율(相對含水率)로 나타내면 잣나무 90%, 리기다 93%, 소나무 90% 일본잎갈나무 93% 전후(前後)에서 초기기공폐쇄(初期氣孔閉鎻)가 일어났다. 4. leaf conductance가 증가(增加)함에 따라 팽압(膨壓)은 증가(增加)하며, 상대함수율(相對含水率)이 증가(增加)함에 따라 팽압(膨壓)은 직선적(直線的)으로 증가(增加)하였다.

• 한국토양비료학회지
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• 제48권6호
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• pp.712-723
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• 2015

This study was conducted to develop the SWCC estimation equation using scaling technique, and to investigate relative sensitivity of the SWCC according to the soil water tension, for the four kinds of soil texture such as Sand [S], Sandy Loam [SL], Loam [L] and Clay Loam [CL]. The SWCC estimation equation of scale factor [${\Theta}sc$] (Eq. 1) was developed based on the log function (Eq. 2) and exponential function (Eq. 3). ${\Theta}sc=[({\Theta}-{\Theta}r)/({\Theta}s-{\Theta}r)]$ (Eq. 1) ${\Theta}sc=-0.196ln(H)+0.4888$ (Eq. 2) ${\Theta}sc=0.3804(H)^{(-0.448)}$ (Eq. 3) where, ${\Theta}$: water content (g/g %), ${\Theta}s$: water content at 0.1bar, ${\Theta}r$: water content at 15bar, H: soil water tension (matric potential) (bar) Relative sensitivity of soil water content was decreased as increase soil water tension, those according to soil water tension were 0.952~0.620 compared to 0.1bar case. Relative sensitivity of scale factor was also decreased as increase soil water tension, those according to soil water tension were 0.890~0.577 compared to 0.2bar case.

• 한국자원식물학회지
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• 제11권3호
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• pp.307-314
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• 1998

The response of water stree under high and low temperatures, was shown differently according to the longer the suspension period of water supply. Leaf photosynthetic rate(LPS), leaf water potential(WP), relative leaf water content and relative soil water content were lower. At the higher temperatures, the percentate of reduction in LPS and WP was greater than at low temperatures. It is suggested that evaporation rate should be higher in the high temperature than the lower temperature. Also leaf water potential was lower at high temperature than at low temperature. After the 9 th day of treatment , LSP was remarkably reduced at high temperature, but the reduction of LPS was not significant at low temperature. Solidago virga-aurea var. asiatic that maintained LPS of 3rd day after treatment was more strong than other varieties at low temperatures. The silting and curling of leaves were observed symptoms of stress on the 9th day at the both temperatures. The leaves of aster scaber and Ligularia fischeri turned red on the 9th day after treatment at low temperature.

• Current Research on Agriculture and Life Sciences
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• 제21권
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• pp.1-9
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• 2003

본 실험은 염과 건조 스트레스를 받은 벼 식물체의 생리학적 반응을 잎의 수분 보유적인 측면에서 조사하여, 벼의 내성품종과 비내성품종을 효율적으로 선발하기 위한 critical level을 밝혀 내성품종 육성에 응용할 수 있는 기초자료를 제공하고자 수행한 시험결과를 요약하면 다음과 같다. 1. NaCl 및 PEG 처리에 의한 벼 식물체의 반응은 일차적으로 뿌리 신장의 억제가 NaCl 처리에 의해 관찰되었으나, PEG 처리에서는 벼 식물체의 뿌리가 PEG 처리 농도를 증가함에 따라 증가하는 경향이 보였다. 2. NaCl 및 PEG 처리에 의한 벼 식물체의 잎의 RWC와 LWP 사이의 상관관계를 조사한 결과, 40 mM NaCl ($r=0.871^{**}$)와 80 mM NaCl 처리구 ($r=0.934^{**}$) 에서 RWC와 LWP사이에 높은 상관관계가 확인되었으나, PEG 처리에 의한 RWC와 LWP 사이에는 8% PEG 처리구($r=0.789^{**}$)에서만 상관관계를 보였다. 3. RWC와 LWP사이에 높은 상관의 결과로부터 측정방법이 까다로운 LWP보다 간단하게 측정할 수 있는 RWC를 이용하여 염 및 건조 스트레스에 대한 내성 품종을 선발하는 것이 효율적이라 사료된다. 4. 염에 대한 벼 내성품종을 선발할 경우에는 80 mM NaCl을 처리한 후 48시간째에 선발하는 것이 적합하고, 한발에 대한 내성품종 선발에는 8% PEG를 처리한 후 96시간째에 선발을 하는 것이 효율적이라 사료된다.

• The Korean Journal of Ecology
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• 제16권3호
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• pp.353-364
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• 1993

To elucidate ecophysiological factors affecting nutural distribution of evergreen broad-leabed trees in Danohad National Marine Park, water potential, relative water content and photosynthetic activities of 4 species, Cammellia japonica, Machilus thunbergii, Castanopsis cuspidata var.sieboldii and Quercus acuta, were potential began to decrease from 07:00h to its minimum value at 13:00h for C. cuspidata var. sieboldii (-14.3bar) and Q. acuta (-19.4bar) at 16:00 h for M. thunbergii(-17.0bar) and at 19:00 h for C. japonica (-14.5bar), and these showed similar trends to relative water content. Photosynthetic activities of 4 species began to increase from 7:00 h and reached maximum values before their minimum values of water potential occureed. Optimum temperature renges of photosynthetic activities was $18~20^{\circ}C$ for C. japonica - M. thunbergii and $14~16^{\circ}C$ for C. cuspidata var. sieboldii Quercus acuta.Q.acuta had the highest light saturation point of $0.4mM/m^2/s$ and C. japonica the lowest of $0.15mM/m^2/s$. Water potential of 4 species subjected to water stress, began to decrease after 1st day of drought and after 21th day of drought, those of C. japonica, M. thunbergii, C. cuspidata var. sieboldii and Q. acuta decreased to species began to decrease after 7th day of drought and after 21th day, those of M. thunbergii, C. cuspidata var. sieboldii and Q. acuta were dropped to about 50% and C. japonica 83.5%. Photosynthetic activity of 4 specie began to decline in the order of C. cuspidata var. sieboldii, Q.acuta, C. japonica and M. thunbergii after 10th day of drought. These results suggest that the segregated disributions of C. japonica - M. thunbergii on vally positions and C. cuspidata var. sieboldii - Q. acuta on slopes were associated with different responses of water status and photosyntheties to their environment.

• 한국작물학회지
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• 제44권1호
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• pp.55-58
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• 1999

Plant water status during growth is directly and indirectly associated with seed yield. The objective of the present study was to determine the genotypic differences in leaf water characteristics at an early growth stage of soybean [Glycine max (L.) Merrill] plants through the pressure-bomb technique. Measurements of water potential as well as relative water content (RWC) were made at the third leaf from the fully-expanded top leaf of eight different soybean genotypes grown for 31 to 35 days after field emergence. On the basis of the modified exponential model, pressure-volume (PV) curves were fitted well ($R^2$=0.92＊＊ to 0.99＊＊ for the curvi-linear region and R=0.67＊＊ to 0.96＊＊ for the linear region), indicating that a segmented model using PROC NLIN of SAS could be used effectively to estimate the leaf water characteristics. The regression analysis for the pressure-volume (PV) curve revealed genotypic variation in the solute potential at saturation (Ψ$_{s,sat}$ :-10.7 to -14.8 bar), solute potential at incipient plasmolysis (Ψ$_{s,ip}$ : -14.3 to -18.3 bar), RWC at incipient plasmolysis (RW $C_{ip}$ : 83.3 to 91.7%), high integrated turgor pressure from saturation to plasmolysis ( $_1$$^{b}$ : 0.39 to 0.81), and maximum volumetric modulus of elasticity ($\varepsilon$$_{max}$ : 150 to 445 bar).).

• 한국작물학회지
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• 제48권6호
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• pp.506-515
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• 2003

이 논문은 한발저항성이 다른 6개 보리 품종의 한발에 따른 생장, 잎의 수분포텐셜(leaf water potential, LWP), 상대함수량(leaf relative water content, RWC), 삼투압(leaf osmotic potential, OP), 삼투조정(osmotic adjustment, OA), 팽압(leaf turgor pressure, LTP), 순광합섬, 기공전도도, 엽육전도도, 엽록소형광 등의 변화를 조사하여 비교한 결과를 요약하면 다음과 같다. 1 한발 처리시 토양수분포텐셜은 -0.05㎫이었고. 종료시에는 -0.29㎫로 저하하였다. Dicktoo-S 동보리 1호, Dicktoo-L, Dicktoo-T, 수원쌀보리 365호, 탑골보리 품종의 한발처리구 건물중은 각각 대조구(처리기간종 -0.05㎫ 유지)에 비하여 68%, 69%, 70%, 86%, 55%, 37%를 나타내어 Dicktoo 계통과 동보리1호의 한발저항성이 강하였고, 수원쌀보리 365호와 탑골보리는 한발저항성이 약하였다. 2. 한발저항성이 강한 품종은 삼투조정능력이 커서 한발처리에 따른 RWC와 LWP의 저하가 작았고 팽압유지능력이 컸다. 3. 한발처리에 따라 순광합성이 저하하였고 그 저하정도는 한발저항성이 큰 품종이 작았는데, 이는 한발저항성이 큰 품종이 기공전도도, 엽육전도도 및 PSII 최대양자수율(Fv/Fm)의 저하가 적었기 때문이었다. 4. 결론적으로 저항성이 큰 품종은 삼투조정에 의한 수분유지능력이 크고 이에 따라 광합성저하가 적어 상대적으로 생장의 감소가 적은 것으로 판단되었다.

• 한국작물학회지
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• 제42권5호
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• pp.632-639
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• 1997

본 실험은 담배의 최대생장 후반기에 수분제한처리를 하여, 한발이 엽위에 따라 생장과 발달에 미치는 영향을 분석하고, 엽영에 따른 엽내 수분상태가 기공컨덕턴스, 잎수분포텐셜과 토양수분관계에 영향을 미치는 생리적 반응을 구명하고져 실시하였다. 담배의 최대생장기 한발영향은 지상부의 제형질을 감소시켰고, 엽위에 따른 생장반응은 중ㆍ하위엽에서 작았고 상위엽에서 컸다. 처리 5일째에 잎의 상대수분함량은 토양수분함량이 4.3%로 감소될 때 상위엽 74%, 중위엽 64%, 하위엽 59%로 담배잎의 위주점은 상대수분함량이 약 75%이었다. 한발에 따른 잎수분포텐셜은 대조구의 -0.58 MPa에서 처리구의 처리5일째에 -1.20 MPa로 떨어졌고, 대조구와 비교하여 약 20%의 수분포텐셜차이가 위주점이 되었다. 기공컨덕턴스는 중ㆍ상위엽에서 12 mol /$\textrm{m}^2 sec^{-1}$에서 0.8 mol /$\textrm{m}^2 sec^{-1}$로 떨어져, 한발처리에 따른 담배의 최대생장후반기의 엽위에 따른 생장반응은 중ㆍ상위엽까지 영향을 미쳤다.

• The Korean Journal of Ecology
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• 제9권4호
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• pp.201-208
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• 1986

The water status of the leaves of several evergreen plants was investigated in order to discuss the geopgraphical distribution of them. Relastionship between relative water content and water potential of the leaves showed linear decrease for evergreen conifers but exponential decrease for Korean box tree (Buxus microphylla var. koreana). On the basis of the leaf water potential, the water status of the conifers during wintering was distinctly divided into three periods; hardening, cold resistance and dehardening, but lacking in those periods for the Korean box tree, where the status continously decreased. In the cold resistance the leaf water potentials were -23 bar for both spruce (Picea jezoensis) and yew (Taxus cuspidata). From these results and threshold temperature at beginning of hardening, distribution of the conifers was explained that in order of the red pine, the Korean white pine, the yew and the spruce the distribution could be extended at higher altitudes and in more northward areas, whereas the distribution of the Korean box tree was restricted to the lowland of temperate zone.