scholarly journals Alteration of Components of Leaf Water Potential and Water Content in Velvetleaf under the Effects of Long-Term Humidity Difference

1992 ◽  
Vol 98 (3) ◽  
pp. 966-970 ◽  
Author(s):  
Yao-Hua Luo ◽  
Boyd R. Strain
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Leaf Water Potential ◽  
Leaf Water

Seasonal changes in leaf water potential components in two almond cultivars

1993 ◽  
Vol 120 (3) ◽  
pp. 347-351 ◽  
Author(s):  
M. C. Ruíz-Sánchez ◽  
M. J. Sánchez-Blanco ◽  
J. Planes ◽  
J. J. Alarcón ◽  
A. Torrecillas
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Volume Curve ◽  
Pressure Volume Curve ◽  
Leaf Osmotic Potential ◽  
Relative Water ◽  
Almond Trees ◽  
Amygdalus Communis

SUMMARYAlmond trees (Amygdalus communis L. cvs Garrigues and Ramillete) were grown in the field under non-irrigated conditions in Murcia, Spain. Seasonal variations in leaf water potential components were studied in 1989. Predawn leaf water potential showed high values in both cultivars, due to the absence of soil water stress. Pressure-volume curve analysis indicated that the leaf osmotic potential at full saturation (Ψo(sat)) for cv. Garrigues remained fairly constant throughout the season. Bulk modulus of elasticity (E) showed, in both cultivars, a tendency to decrease as the season progressed. E values were higher in Ramillete than in Garrigues. The relative water content at the turgor loss point (RWCtlp) seemed to be controlled by E values. The larger relative apoplastic water content (RWCa found in Ramillete might have allowed it to retain more water at low leaf water potentials than Garrigues. These facts would support the suggestion that Ramillete is a more drought-resistant cultivar than Garrigues.

Water Relations and Leaf Structure of the Evergreen Shrubs Eurya emarginata (Theaceae) and E. japonica in Coastal and Inland Habitats

1998 ◽  
Vol 46 (1) ◽  
pp. 135 ◽  
Author(s):  
Masako Mishio ◽  
Naoki Kachi
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Water Content ◽  
Leaf Water Potential ◽  
Unit Area ◽  
Leaf Water ◽  
Photon Flux ◽  
Leaf Water Content ◽  
Shrub Species ◽  
Eurya Emarginata

Stomatal conductance and leaf water potential at around noon, pre-dawn leaf water potential, pressure–volume parameters, and leaf structural characteristics including leaf thickness, leaf dry mass per unit area and turgid leaf water content per unit area were compared between a coastal shrub species, Eurya emarginata (Thunb.) Makino and an inland shrub species, E. japonica Thunb. The pre-dawn leaf water potential was only slightly lower in E. emarginata than in E. japonica, and the environmental conditions such as the photosynthetic photon flux density and the vapour pressure deficit did not differ obviously between the two habitats. No apparent differences were observed in the pressure–volume parameters between the two species. On the other hand, E. emarginata had much higher stomatal conductance and significantly thicker leaves with higher turgid leaf water content per unit area than E. japonica. The thicker leaf with higher water content on an area basis in E. emarginata maintains adequate leaf turgor pressure against a higher rate of transpiration.

Anomalous Water Relations in Copper-Deficient Wheat Plants

1976 ◽  
Vol 3 (2) ◽  
pp. 229 ◽  
Author(s):  
RD Graham
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Leaf Water Potential ◽  
Copper Deficiency ◽  
Water Status ◽  
Specific Effect ◽  
Water Levels ◽  
Leaf Water ◽  
Diffusive Resistance ◽  
Effect Of Copper

Leaf water potential, diffusive resistance, relative water content, weekly water use, yields and head bending were measured on wheat plants subjected to four copper levels (0, 0.4, 0.8 or 4.0 mg Cu per pot) and two water levels (6 or 12% soil water content). Severe copper deficiency (Cu 0) resulted in no grain yield, wilting, increased leaf diffusive resistance and, at the same time, increased leaf water potential relative to plants receiving 4.0 mg Cu (Cu 4.0). Water supply effects were observed but there was no interaction between copper and water treatments. Mild copper deficiency (Cu 0.4, Cu 0.8) resulted in small yield decreases, relative to Cu 4.0, and increased head bending towards maturity. It is concluded that wilting, characteristic of copper-deficient plants, is due to structural weakness (decreased lignification) and not to the water status of the plants; also, increased leaf diffusive resistance is due to a specific effect of copper deficiency on guard cells and not to decreased leaf water potential.

scholarly journals Relationships Among Water Potential Components, Relative Water Content, and Stomatal Resistance of Field-Grown Peanut Leaves1

1984 ◽  
Vol 11 (1) ◽  
pp. 31-35 ◽  
Author(s):  
J. M. Bennett ◽  
K. J. Boote ◽  
L. C. Hammond
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Leaf Water Potential ◽  
Relative Water Content ◽  
Leaf Water ◽  
Peanut Crop ◽  
Relative Water ◽  
Volumetric Soil Water

Abstract Limited data exist describing the physiological responses of peanut (Arachis hypogaea L.) plants to tissue water deficits. Detailed field experiments which accurately define the water status of both the plant and soil are required to better understand the effects of water stress on a peanut crop. The objectives of the present study were 1) to describe the changes in leaf water potential components during a drying cycle, and 2) to define the relationships among soil water content, leaf water potential, leaf turgor potential, relative water content, leaf-air temperature differential, and leaf diffusive resistance as water stress was imposed on a peanut crop. During a 28-day drying period where both rainfall and irrigation were withheld from peanut plants, midday measurements of the physiological parameters and volumetric soil water contents were taken concurrently. As soil drying progressed, water extraction from the upper soil depths was limited as soil moisture approached 0.04 m3m-3. Leaf water potentials and leaf turgor potentials of nonirrigated plants decreased to approximately −2.0 and 0 MPa, respectively, by the end of the experimental period. Leaf water potentials declined only gradually as the average volumetric soil water content in the upper 90 cm of soil decreased from 0.12 to 0.04 m3m-3. Further reductions in soil water content caused large reductions in leaf water potential. As volumetric soil moisture content decreased slightly below 0.04 m3m-3 in the upper 90 cm, leaf relative water content dropped to 86%, leaf water potential approached −1.6 MPa and leaf turgor potential decreased to 0 MPa. Concurrently, stomatal closure resulted and leaf temperature increased above air temperature. Osmotic potentials measured at 100% relative water content were similar for irrigated and nonirrigated plants, suggesting little or no osmotic regulation.

scholarly journals Comparison of Strawberry F. chilocnsis and F. ×ananassa in Response to Water Stress: I. Leaf Water Potential, Relative Water Content, and Gas Exchange Characteristics

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 601c-601
Author(s):  
Chuhe Chen ◽  
J. Scott Cameron ◽  
Stephen F. Klauer
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Potential ◽  
Water Content ◽  
Leaf Water Potential ◽  
Relative Water Content ◽  
Leaf Water ◽  
Severe Water Stress ◽  
Relative Water ◽  
Gas Exchange Characteristics

Leaf water potential (LWP), relative water content (RWC), gas exchange characteristics, and specific leaf weight (SLW) were measured six hours before, during, and after water stress treatment in F. chiloensis and F. ×ananassa grown in growth chambers. The leaves of both species showed significantly lower LWP and RWC as water stress developed. F. ×ananassa had consistency lower LWP under stressed and nonstressed conditions than F. chiloensis. F. ×ananassa had higher RWC under nonstressed conditions, and its RWC decreased more rapidly under water stress than F. chiloensis. In comparison to F. ×ananassa, F. chiloensis had significantly higher CO2 assimilation rate (A), leaf conductance (LC), and SLW, but not transpiration rate (Tr), under stressed and nonstressed conditions. LC was the most sensitive gas exchange characteristic to water stress and decreased first. Later, A and stomatal conductance were reduced under more severe water stress. A very high level of Tr was detected in F. ×ananassa under the most severe water stress and did not regain after stress recovery, suggesting a permanent damage to leaf. The Tr of F. chiloensis was affected less by water stress. Severe water stress resulted in higher SLW of both species.

The leaf miner Phyllocnistis populiella negatively impacts water relations in aspen

2019 ◽  
Vol 40 (5) ◽  
pp. 580-590 ◽  
Author(s):  
Diane Wagner ◽  
Jenifer M Wheeler ◽  
Stephen J Burr
Keyword(s):  
Water Vapor ◽  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Leaf Water Potential ◽  
Water Loss ◽  
Stomatal Closure ◽  
Leaf Water ◽  
Leaf Miner ◽  
Phyllocnistis Populiella

Abstract Within the North American boreal forest, a widespread outbreak of the epidermal leaf miner Phyllocnistis populiella Cham. has damaged quaking aspen (Populus tremuloides Michx.) for nearly 20 years. In a series of experiments, we tested the effects of feeding damage by P. populiella on leaf water relations and gas exchange. Relative to insecticide-treated trees, the leaves of naturally mined trees had lower photosynthesis, stomatal conductance to water vapor, transpiration, water-use efficiency, predawn water potential and water content, as well as more enriched foliar δ13C. The magnitude of the difference between naturally mined and insecticide-treated trees did not change significantly throughout the growing season, suggesting that the effect is not caused by accumulation of incidental damage to mined portions of the epidermis over time. The contributions of mining-related stomatal malfunction and cuticular transpiration to these overall effects were investigated by restricting mining damage to stomatous abaxial and astomatous adaxial leaf surfaces. Mining of the abaxial epidermis decreased photosynthesis and enriched leaf δ13C, while increasing leaf water potential and water content relative to unmined leaves, effects consistent with stomatal closure due to disfunction of mined guard cells. Mining of the adaxial epidermis also reduced photosynthesis but had different effects on water relations, reducing midday leaf water potential and water content relative to unmined leaves, and did not affect δ13C. In the laboratory, extent of mining damage to the adaxial surface was positively related to the rate of water loss by leaves treated to prevent water loss through stomata. We conclude that overall, despite water savings due to closure of mined stomata, natural levels of damage by P. populiella negatively impact water relations due to increased cuticular permeability to water vapor across the mined portions of the epidermis. Leaf mining by P. populiella could exacerbate the negative effects of climate warming and water deficit in interior Alaska.

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