Changes in shoot water relations parameters of yellow-cedar (Chamaecyparis nootkatensis) in response to environmental conditions

1996 ◽  
Vol 74 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Steven C. Grossnickle ◽  
John H. Russell
Keyword(s):  
Water Relations ◽  
Environmental Conditions ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Late Summer ◽  
Water Relation ◽  
Elastic Component ◽  
Root Temperature ◽  
Turgor Loss Point ◽  
Chamaecyparis Nootkatensis

Yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) shoot water relations parameters were measured in response to (i) seasonal changes in photoperiod and temperature and (ii) controlled changes in root temperature and soil moisture. Pressure–volume curves determined measurements of shoot water relation parameters. Osmotic potential at saturation (Ψsat) and turgor loss point (Ψtlp) were lowest during February at −1.73 and −2.35 MPa, respectively. Both Ψsat and Ψtlp increased in the spring to a high in July of −1.05 and −1.28 MPa, respectively, when shoot growth was occurring. Total turgor (ΨPTotal) was 18.2 MPa in December and declined to its lowest level of 5.98 MPa in July. Increased ΨPTotal from late summer through winter could be attributed to osmotic and (or) elastic components, while decreased ΨPTotal in the spring was due to a decrease in both osmotic and elastic components. Both Ψsat and Ψtlp decreased as root temperatures were reduced from 22 to 1 °C. There was an increase in ΨPTotal as root temperatures declined from 15 to 8 °C because of both osmotic and elastic adjustment, with osmotic adjustment the primary factor. Turgor decreased at root temperatures below 8 °C, even though osmotic adjustment was occurring, and this was due to a reduction in the elastic component. Both Ψsat and Ψtlp decreased in response to drought, though Ψtlp decreased at a greater rate. Increased turgor during the initial stages of long-term drought results from an increase in both osmotic and elastic components, while increased turgor was solely due to the osmotic component as drought became more severe. Under rapid drought, turgor adjustment was minimal because the increased osmotic component was offset by a decrease in the elastic component. Results from these experiments indicate that turgor maintenance of yellow-cedar occurs through the use of both osmotic and elastic components in varying degrees at different times of the year and under differing environmental conditions. Keywords: Chamaecyparis nootkatensis, osmotic potential at saturation and turgor loss point, total turgor with osmotic and elastic components, seasonal patterns, root temperature, drought.

Seasonal trends of several water relation parameters in Cryptomeriajaponica seedlings

1986 ◽  
Vol 16 (1) ◽  
pp. 74-77 ◽  
Author(s):  
Kyoji Doi ◽  
Yasushi Morikawa ◽  
Thomas M. Hinckley
Keyword(s):  
Water Relations ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Dry Weight ◽  
Water Relation ◽  
Evaporative Demand ◽  
Seasonal Trends ◽  
Air Temperatures ◽  
Turgor Maintenance

The role of osmotic adjustment in turgor maintenance during periods of either cold soil or plant temperatures or of high evaporative demand was described for 2-year-old Cryptomeriajaponica D. Don seedlings. Water relations parameters were measured by the pressure–volume technique for a 1-year period. The osmotic potential at full turgidity and at the point of zero turgor ranged from −1.32 to −2.70 MPa and from −1.70 to −3.52 MPa, respectively. Highest values of osmotic potential were associated with the period of foliage expansion, while lowest values were noted in mid-February during the period of lowest air temperatures. The role of solute changes or changes in symplastic water relative to tissue dry weight in osmotic adjustment is described.

Interior spruce seedlings compared with emblings produced from somatic embryogenesis. II. Stock quality assessment prior to field planting

1994 ◽  
Vol 24 (7) ◽  
pp. 1385-1396 ◽  
Author(s):  
S.C. Grossnickle ◽  
J.E. Major
Keyword(s):  
Somatic Embryogenesis ◽  
Quality Assessment ◽  
Root Development ◽  
Osmotic Potential ◽  
Assessment Procedure ◽  
Performance Potential ◽  
Root Temperature ◽  
Turgor Loss Point ◽  
Interior Spruce ◽  
Stock Quality

Interior spruce (Piceaglauca (Moench) Voss × Piceaengelmannii Parry) seedlings and emblings produced through somatic embryogenesis tissue culture were removed from frozen storage and tested with a stock quality assessment procedure prior to spring planting. Seedlings, compared with emblings, had greater height as well as shoot and root dry weights. Seedlings and emblings had similar root-collar diameter, buds per total shoot length, and needle primordia in their terminal buds. Seedlings and emblings had similar shoot form (i.e., branch quotient) and balance between their shoot and root system (i.e., plant water balance ratio). Emblings, compared with seedlings, had a lower osmotic potential at turgor loss point and symplastic fraction, plus a higher dry weight fraction and total turgor. Seedlings and emblings had similar osmotic potential at saturation and relative water content at turgor loss point. Seedlings and emblings had similar resistance to water movement through the plant–atmosphere continuum (Rpac) at 22 °C root temperature, though emblings had greater Rpac at 7.5 °C root temperature. Seedlings had greater net photosynthesis (Pn) than emblings over a 14-day period at both 7.5 and 22 °C root temperatures. Seedlings, compared with emblings, had greater root development over a 14-day period at 22 °C root temperature, though they had low and similar root development at 7.5 °C root temperature. Both Pn and needle conductance (gwv) decreased as predawn shoot water potential (Ψpd) declined in seedlings and emblings. Nearly complete stomatal closure occurred at Ψpd less than −1.5 MPa, while similarly low Pn readings (seedlings: −0.01 ± 0.04 μmol•m−2•s−1; emblings: 0.02 + 0.04 μmol•m−2•s−1) occurred between a Ψpd of −1.0 and −2.0 MPa. A performance potential index (PPI), which combines material and performance attributes in a comprehensive characterization of field performance potential, indicated that seedlings had a better PPI under optimum environmental conditions. However, seedlings and emblings had similar PPI under low temperature and drought conditions.

Water-stress tolerance and late-season organic solute accumulation in hybrid poplar

1989 ◽  
Vol 67 (6) ◽  
pp. 1681-1688 ◽  
Author(s):  
T. J. Tschaplinski ◽  
T. J. Blake
Keyword(s):  
Water Stress ◽  
Stress Tolerance ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Soluble Sugar ◽  
Hybrid Poplar ◽  
Turgor Loss Point ◽  
Water Stress Tolerance ◽  
Organic Solute ◽  
The Relationship

Organic solute concentrations of five hybrid poplar cultivars were compared to determine the relationship between water-stress tolerance, tissue solute concentration, and growth rate under field conditions. In the expanding foliage of the faster growing Populus deltoides Bartr. × P. balsamifera L. (Jackii 4), the saturated osmotic potential and turgor loss point osmotic potential were 0.18 MPa and 0.47 MPa lower, respectively, than in the slower growing P. deltoides × P. balsamifera (Jackii 7). The expanding foliage of Jackii 4 had higher (ca. 50%) concentrations of organic solutes, attributable mainly to salicyl alcohol, salicin, sucrose, and an unidentified compound. The coupling of high productivity and stress tolerance in Jackii 4 suggests that these may be compatible rather than competing attributes. Water-stress studies on P. deltoides Bartr. × P. nigra L. (DN 22) under greenhouse conditions demonstrated that stressed trees accumulated 4 times the soluble sugar concentrations of well-watered trees, lowering the saturated osmotic potential by 0.55 MPa and turgor loss point osmotic potential by 1.0 MPa. Leaves were the primary site of osmotic adjustment to water stress and roots showed no adjustment. The use of repeated drying cycles in planting stock may aid survival of postplanting stress in species capable of osmotic adjustment. The relationship between stress tolerance and solute concentrations in the greenhouse water-stress study paralleled that of the field study.

Tissue water relations of Pinusponderosa and Arctostaphylospatula exposed to various levels of soil moisture depletion

1994 ◽  
Vol 24 (7) ◽  
pp. 1495-1502 ◽  
Author(s):  
Paul D. Anderson ◽  
John A. Helms
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Water Relations ◽  
Osmotic Adjustment ◽  
Moisture Regime ◽  
Tissue Elasticity ◽  
Tissue Water ◽  
Turgor Loss Point ◽  
Moisture Availability ◽  
Osmotic Potentials

The tissue water relations of Pinusponderosa Dougl. ex Laws, (ponderosa pine) and Arctostaphylospatula Greene (greenleaf manzanita) seedlings subjected to three levels of soil moisture availability were monitored over a 6-month period. Throughout the study, osmotic potentials at full turgor and at the turgor loss point were approximately 0.5 MPa greater for pine than for manzanita. Osmotic adjustment occurred for both species as evidenced by declines in osmotic potentials at full turgor and at the turgor loss point of 0.5–0.6 MPa over the study period. Pine maintained higher bulk tissue elasticity and lower water content at the turgor loss point relative to manzanita. Moisture regime had little effect on the measured parameters except for apoplasmic water content which increased at moderate and high stress levels for both species. Results suggest that osmotic adjustment occurred, at least partially, as a result of factors other than moisture availability. The lower tissue elasticity and higher water content at the turgor loss point for manzanita suggest that the shrub species is more dependent upon high foliar water content for the maintenance of turgor compared with the conifer.

Shoot phenology and water relations of Piceaglauca

1989 ◽  
Vol 19 (10) ◽  
pp. 1287-1290 ◽  
Author(s):  
Steven C. Grossnickle
Keyword(s):  
Osmotic Potential ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Water Relation ◽  
Day Length ◽  
Late Winter ◽  
Turgor Loss Point ◽  
Shoot Dry Weight ◽  
Length Changes ◽  
Shoot Phenology

Piceaglauca var. albertiana (S. Brown) Sarg. shoot phenology and water relation parameters were monitored monthly for 1 year. Seedlings were kept outdoors, well watered, and exposed to seasonal changes in temperature and day length. Changes in shoot water relation parameters corresponded with changes in phenology. During spring, shoot elongation, osmotic potential at saturation, and turgor loss point were least negative, −1.30 and −1.56 MPa, respectively, whereas bulk modulus of elasticity at full turgor was at its highest, 22 MPa. Both osmotic potential at saturation and turgor loss point were most negative, −2.01 and −2.73 MPa, respectively, during late winter just before bud break. Shoot dry weight fraction was at its lowest, 0.33 g dry wt./g shoot weight and maximum symplastic water per unit weight of shoot tissue was at its highest, 3.99 g H2O/g dry wt., during spring shoot elongation. Number of osmoles of solute per kilogram shoot dry weight was highest during spring and late summer shoot elongation phases, 1.03 and 0.91 osmol/kg dry wt., respectively. These data suggest that P. glauca seedlings do not adjust well to dry site conditions.

Comparing plant water relations for wheat with alternative pulse and oilseed crops grown in the semiarid Canadian prairie

2009 ◽  
Vol 89 (5) ◽  
pp. 823-835 ◽  
Author(s):  
H W Cutforth ◽  
S V Angadi ◽  
B G McConkey ◽  
M H Entz ◽  
D Ulrich ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Relations ◽  
Leaf Water Potential ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Leaf Water ◽  
Oilseed Crops ◽  
Pulse Crops ◽  
The Mean

Understanding the drought physiology of alternate crops is essential to assess the production risks of new cropping systems. We compared the water relations of dry (field) pea (Pisum sativum L.), chickpea (Cicer arietinum L.), canola (Brassica napus L.) and mustard (Brassica juncea L.) with spring wheat (Triticum aestivum L.) under different moisture availabilities in field trials conducted in 1997 and 1998 at Swift Current, SK. Stress experience and stress responses varied with crop type. In general, there were similarities in drought physiology between the two pulse crops and between the two oilseed crops. The mean predawn leaf water potential of pea was frequently lowest, while the mean midday leaf water potential of wheat was at least -0.40 MPa lower than for any other crop. The crops exhibited different strategies to overcome water stress. Wheat had the lowest osmotic potential at full turgor, except under drought when turgor was lowest for chickpea and wheat; the highest values were observed in Brassica spp. Mean midday pressure potentials were lowest in wheat (and mostly negative, indicating loss of turgor) and highest for the pulse crops. Mean midday pressure potential for canola was positive when well-watered, otherwise it was near 0. Despite lowering osmotic potential, wheat could not maintain positive turgor much of the time at midday. Pulse crops, with the contributions from both osmotic adjustment and cell elasticity, maintained positive turgor over a wider range of water potentials compared with the other crops. With regard to both osmotic adjustment and tissue elasticity, we ranked the crops from high to low ability to adjust to moderate to severe water stress as pulses > wheat > Brassica oilseeds. Key words: Leaf water, osmotic, turgor potentials, wheat, pulse, canola, semiarid prairie

scholarly journals Water Relation Parameters of the Cortex Tissue of Fresh ‘Fuji’ Apple Fruit Determined by Centrifugation

HortScience ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Xue-Min Hou ◽  
Zi-Hua Wang ◽  
Xi-Min Deng ◽  
Guo-Hui Li
Keyword(s):  
Elastic Modulus ◽  
Osmotic Potential ◽  
Water Relation ◽  
Apple Fruit ◽  
Pressure Potential ◽  
Centrifuge Method ◽  
Turgor Loss Point ◽  
Relative Water ◽  
Fuji Apple ◽  
Bulk Elastic Modulus

This experiment was carried out to obtain a pressure–volume (P-V) curve and Höfler diagram of the cortex tissue of fresh ‘Fuji’ apple fruit (Malus ×domestica Borkh.) with a novel centrifuge method. Based on the P-V curve and Höfler diagram, several water relation parameters of cortex tissue were determined and the interrelationship of these parameters was established. Turgor loss point (TLP) occurred at –1.74 MPa and 73.7% of relative water content (R*). At full hydration, osmotic potential (ψS) was –1.30 MPa and symplastic water accounted for 86.8% of R*. Bulk elastic modulus decreased linearly by 28% as pressure potential declined from 1.30 MPa at full hydration to zero at the TLP. This centrifuge technique can provide a simple and efficient way to determine water relation parameters of fleshy fruits.

Leaf and root osmotic adjustment in drought-stressed Quercusalba, Q. macrocarpa, and Q. stellata seedlings

1988 ◽  
Vol 18 (1) ◽  
pp. 1-5 ◽  
Author(s):  
William C. Parker ◽  
Stephen G. Pallardy
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Root Tissue ◽  
Tissue Elasticity ◽  
Tissue Water ◽  
Before And After ◽  
Relative Water

The leaf and root tissue water relations of Quercusalba L., Quercusmacrocarpa Michx., and Quercusstellata Wang. seedlings before and after drought were examined to evaluate the occurrence and comparative extent of osmotic adjustment in seedlings of these species. Drought resulted in active osmotic adjustment in leaves of all three species, with decreases in osmotic potential at full tissue hydration and at the turgor loss point from 0.25 to 0.60 MPa. Active osmotic adjustment in Q. stellata, and increased root tissue elasticity in Q. macrocarpa and Q. alba, resulted in turgor loss of roots occurring at a water potential 0.36 to 0.66 MPa lower in drought-stressed than in well-watered seedlings. Species differed in tissue water relations only before drought, with Q. stellata exhibiting lower osmotic potentials than Q. alba and Q. macrocarpa. Estimates of the osmotic potential at full saturation were generally lower in leaves than in roots, but the osmotic potential at turgor loss was similar. Roots exhibited turgor loss at lower values of relative water content and experienced a more gradual decrease in water potential per unit water content during dehydration than did leaves. This response indicates greater relative tissue capacitance in roots than in leaves in these species.

ROOTING CAPABILITY AS IT RELATES TO SOIL MOISTURE EXTRACTION AND OSMOTIC POTENTIAL OF SEMIDWARF AND NORMAL-STATURED GENOTYPES OF SIX-ROW BARLEY (HORDEUM VULGARE L.)

1980 ◽  
Vol 60 (1) ◽  
pp. 241-248 ◽  
Author(s):  
R. B. IRVINE ◽  
B. L. HARVEY ◽  
B. G. ROSSNAGEL
Keyword(s):  
Water Uptake ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
P Uptake ◽  
Relative Distribution ◽  
Hordeum Vulgare L ◽  
Normal Height ◽  
Rooting Medium ◽  
Moisture Extraction ◽  
Osmotic Potentials

The rooting capabilities of four semidwarf and two normal-statured genotypes were estimated by 32P uptake and extraction of roots from a column of soil. The two height groups did not differ in root volume when the plants were grown in a rooting medium composed of three parts sand and one part topsoil. Rooting was estimated under field conditions by placing 32P in the soil at 15, 30, 60, and 90 cm and measuring 32P activity in the aerial plant portions 15, 30, 45 and 61 days from seeding. Semidwarf and normal-statured types had the same relative distribution of 32P uptake on all days. Water uptake by semidwarf and normal height genotypes was similar over the season in both environments receiving incident rainfall. There was a significant effect of environment on the osmotic potential of the last fully developed leaf. Plants growing in environments with low soil water developed lower osmotic potentials. However, there were no differences in genotypic reponse indicating similar osmotic adjustment. It was concluded that semidwarf and normal genotypes do not differ in rooting water uptake or osmotic adjustment due to plant stature.

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