Osmotic Adjustment and Solute Accumulation in Two Wheat Genotypes Differing in Drought Resistance<sup>1</sup>

Johnson, R. C.; Nguyen, Huy; Croy, L. I.

doi:10.2135/cropsci1984.0011183x002400050032x

Cited by 59 publications

(27 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Landraces differed significantly for osmotic adjustment under PEG-induced water stress . Values reaching 0 .9 MPa of osmotic adjustment, as measured here, may be considered high in wheat (Blum et al, 1983c ;Johnson et al ., 1984) . Growth reduction by PEG-induced water stress tended to be smaller for landraces with greater osmotic adjustment, showing that drought resistance and growth were associated with the osmotic adjustment of landraces within an experiment .…”

Section: Discussionsupporting

confidence: 54%

The drought response of landraces of wheat from the northern Negev Desert in Israel

et al. 1989

View full text Add to dashboard Cite

Diverse landraces of wheat, collected from the semi-arid (150 to 250 mm of total annual rainfall) Northern Negev desert in Israel were considered as a potential genetic resource of drought resistance for wheat breeding . These materials were therefore evaluated for their reponses to drought stress in agronomical and physiological terms . Up to 68 landraces, comprising of Triticum durum, T aestivum, and T compactum were tested in two field drought environments, in one favourable field environment, under post-anthesis chemical plant desiccation which revealed the capacity for grain filling from mobilized stem reserves, under a controlled drought stress in a rainout shelter and in the growth chamber under polyethylene glycol (PEG)-induced water stress . Biomass, grain yield and its components, harvest index, plant phenology, canopy temperatures, kernel weight loss by chemical plant desiccation, growth reduction by PEG-induced drought stress and osmotic adjustment were evaluated in the various experiments .Landraces varied significantly for all parameters of drought response as measured in the different experiments, which was in accordance to their documented large morphological diversity . Variation in grain yield among landraces under an increasing drought stress after tillering was largely affected by spike number per unit area . Kernel weight contributed very little to yield variation among landraces under stress, probably because these tall (average of 131 cm) landraces generally excelled in their capacity to support kernel growth by stem reserve mobilization under stress . Yield under stress was reduced with a longer growth duration of landraces only under early planting but not under late planting . Landraces were generally late flowering but they were still considered well adapted phenologically to their native region where they were always planted late .Landraces differed significantly in canopy temperature under drought stress . Canopy temperature under stress in the rainout shelter was negatively correlated across landraces with grain yield (r = 0 .67**) and biomass (r = 0 .64* *) under stress . Canopy temperature under stress in the rainout shelter was also positively correlated across landraces (r = 0 .50**) with canopy temperature in one stress field environment . Osmotic adjustment in PEG-stressed plants was negatively correlated (r = -0 .60**) with percent growth reduction by PEG-induced water stress . It was not correlated with yield under stress in any of the experiments .In terms of yield under stress, canopy temperatures and stem reserve utilization for grain filling, the most drought resistant landrace was the 'Juljuli' population of T durum . 88

show abstract

Section: Discussionsupporting

confidence: 54%

The drought response of landraces of wheat from the northern Negev Desert in Israel

et al. 1989

View full text Add to dashboard Cite

show abstract

“…In wheat e has been found to increase in leaves which have been exposed to prolonged drought conditions due to thicker and more rigid cell walls which develop under such growth conditions (Johnson et al, 1984;Melkonian et al, 1982). In contrast, e decreased in pot grown wheat (Kikuta and Richter, 1986) exposed to less prolonged water stress periods than in our experiment, and Campbell et al (1979) found no significant difference in E of winter wheat grown under relatively dry versus relatively wet field conditions.…”

Section: Discussioncontrasting

confidence: 63%

Leaf water relations characteristics of differently potassium fertilized and watered field grown barley plants

Jensen¹,

Andersen²,

Lösch

1992

Plant Soil

View full text Add to dashboard Cite

Seasonal leaf water relations characteristics were studied in fully irrigated spring barley (Hordeum distichum L. cv. Gunnar) fertilized at low (50 kg K ha -1) or high (200 kg K ha -I) levels of potassium applied as KCI. The investigation was undertaken from about 14 days before anthesis until the milk ripe stage in leaves of different position and age. Additionally, the effects of severe water stress on leaf water relations were studied in the middle of the grain filling period in spring barley (cv. Alis). The leaf water relations characteristics were determined by the pressure volume (PV) technique.Water relations of fully irrigated plants were compared in leaf No 7 with the water relations of slowly droughted plants (cv. Alis). Leaf osmotic potential at full turgor (01°°) decreased 0.1 to 0.3 MPa in droughted leaves indicating a limited osmotic adjustment due to solute accumulation. The leaf osmotic potential at zero turgor (q0) was about -2.2 MPa in fully irrigated plants and -2.6 MPa in droughted plants. The relative water content at zero turgor (R °) decreased 0.1 unit in severely droughted leaves. The ratio of turgid leaf weight to dry weight (TW/DW) tended to be increased by drought. The tissue modulus of elasticity (e) decreased in droughted plants and together with osmotic adjustment mediated turgor maintenance during drought. A similar response to drought was found in low and high K plants except that the R ° and E values tended to be higher in the high K plants. Conclusively, during drought limited osmotic adjustment and increase in elasticity of the leaf tissue mediated turgot maintenance. These effects were only slightly modified by high potassium application.The seasonal analysis in fully irrigated plants (cv. Gunnar) showed that within about 14 days from leaf emergence 4~ ~° decreased from about -0.9 to -1.6 MPa in leaf No 7 (counting the first leaf to emerge as number one) and from about -1.1 to -1 . 9 M P a in leaf No 8 (the flag leaf) due to solute accumulation. A similar decrease took place in O ° except that the level of 0~ was displaced to a lower level of about 0.2 to 0.3 MPa. Both 02 ~° and qs ° tended to be 0.05 to 0.10 MPa lower in high K than in low K plants. R ° was about 0.8 to 0.9 and was independent of leaf position and age, but tended to be highest in high K plants. The TW/DW ratio decreased from about 5.5 in leaf No 6 to 4.5 in leaf No 7 and 3.8 in leaf No 8. The TW/DW ratio was 4 to 10% higher in high K than in low K plants indicating larger leaf cell size in the former. The apoplastic water content (%1,,) at full turgor constituted about 15% in leaf No 7. E was maximum at full turgor and varied from about 11 to 34 MPa. e tended to be higher in high K plants. Conclusively, in fully watered plants an ontogenetically determined accumula-226 Jensen et al.tion of solutes (probably organic as discussed) occurred in the leaves independent of K application. The main effect of high K application on water relations was an increase in leaf water content and a slight decrease in leaf ~O=.Th...

show abstract

“…In contrast, S. cernuus maintains higher ψ xylem , which would require either an increase in solute concentrations (inorganic and/or organic solutes) or a decrease in tissue water content (i.e. θ) to generate lower ψ xylem (Edwards & Jarvis 1982, Johnson et al 1984, Clifford et al 1998. Thus by lowering θ, S. cernuus would be able to generate lower ψ xylem and thereby maintain favorable plantsoil relations as soils become increasingly dryer.…”

Section: Discussionmentioning

confidence: 99%

Xylem potential- and water content-breakpoints in two wetland forbs: indicators of drought resistance in emergent hydrophytes

Touchette¹,

Frank²

2009

Aquat. Biol.

View full text Add to dashboard Cite

Freshwater wetlands commonly occur along the boundaries between terrestrial upland and deep open-water systems, and are consequently prone to dynamic and often highly variable hydrological regimes. Physiological adaptations to drought would be advantageous in emergent vegetation, as wetlands are often susceptible to short periods of water scarcity through seasonal declines in precipitation and/or surface water runoff. This study used 15 l microcosms to examine xylem water potential (ψ xylem )-and tissue water content (θ)-breakpoints in 2 wetland forbs (Justicia americana and Saururus cernuus) to determine how these plants respond to short-term (2 wk) water deficits. Overall, treatment responses by these forbs included reductions in both θ and ψ xylem during the second week of drought, followed by rapid recoveries of θ and ψ xylem within a few days of water repletion. Rapid tissue-water recovery, following extreme water deficits (soil moisture levels < 3%), is beneficial to plants residing in areas prone to intense water fluctuations. Furthermore, while θ and ψ xylem breakpoints in S. cernuus occurred as soil moisture levels fell below 12% (ca. -800 kPa soil water potential), breakpoints for J. americana occurred at considerably lower soil moisture levels (ca. 7 and 10% soil water content for θ and ψ xylem , respectively; or less than -1500 kPa soil water potential). The lower breakpoints observed in J. americana were comparable to values reported for terrestrial grasses, including species adapted to dryer, xeric conditions. Therefore, the results from this study suggest that some wetland forbs are physiologically adapted to environments that undergo rapid changes in water hydrology, including the ability to tolerate short-term water scarcity comparable to dryer upland systems.

show abstract

Osmotic Adjustment and Solute Accumulation in Two Wheat Genotypes Differing in Drought Resistance¹

Cited by 59 publications

References 0 publications

The drought response of landraces of wheat from the northern Negev Desert in Israel

The drought response of landraces of wheat from the northern Negev Desert in Israel

Leaf water relations characteristics of differently potassium fertilized and watered field grown barley plants

Xylem potential- and water content-breakpoints in two wetland forbs: indicators of drought resistance in emergent hydrophytes

Contact Info

Product

Resources

About

Osmotic Adjustment and Solute Accumulation in Two Wheat Genotypes Differing in Drought Resistance1

Cited by 59 publications

References 0 publications

The drought response of landraces of wheat from the northern Negev Desert in Israel

The drought response of landraces of wheat from the northern Negev Desert in Israel

Leaf water relations characteristics of differently potassium fertilized and watered field grown barley plants

Xylem potential- and water content-breakpoints in two wetland forbs: indicators of drought resistance in emergent hydrophytes

Contact Info

Product

Resources

About

Osmotic Adjustment and Solute Accumulation in Two Wheat Genotypes Differing in Drought Resistance¹