Cell Water Potential Components in the Adaptation of Pseudoroegneria spicata (Pursh) A. Löve to Various Habitat Moisture Conditions

1987 ◽  
Vol 148 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Margaret S. Dibble ◽  
George G. Spomer
1981 ◽  
Vol 17 (2) ◽  
pp. 157-162 ◽  
Author(s):  
R. D. Misra ◽  
P. C. Pant

SUMMARYA field experiment evaluating criteria for scheduling wheat irrigation was conducted from 1975 to 1977 in a sandy loam soil with treatments scheduled according to physiological stages, soil moisture conditions, pan evaporation and leaf water potential. Grain and straw yields, spikes/m, fertile spikelets/spike and number and weight of grains/spike were significantly influenced by treatments. Irrigation based on leaf water potential was as good as when based on physiological stages or soil moisture, and the use of pan evaporation was no better than other methods of scheduling.


HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1178-1187 ◽  
Author(s):  
D. Michael Glenn ◽  
Nicola Cooley ◽  
Rob Walker ◽  
Peter Clingeleffer ◽  
Krista Shellie

Water use efficiency (WUE) and response of grape vines (Vitis vinifera L. cvs. ‘Cabernet Sauvignon’, ‘Merlot’, and ‘Viognier’) to a particle film treatment (PFT) under varying levels of applied water were evaluated in Victoria, Australia, and southwestern Idaho. Vines that received the least amount of water had the warmest canopy or leaf surface temperature and the lowest (more negative) leaf water potential, stomatal conductance (gS), transpiration (E), and photosynthesis (A). Vines with plus-PFT had cooler leaf and canopy temperature than non-PFT vines; however, temperature difference resulting from irrigation was greater than that resulting from PFT. In well-watered vines, particle film application increased leaf water potential and lowered gS. Point-in-time measurements of WUE (A/E) and gS did not consistently correspond with seasonal estimates of WUE based on carbon isotope discrimination of leaf or shoot tissue. The response of vines with particle film to undergo stomatal closure and increase leaf water potential conserved water and enhanced WUE under non-limiting soil moisture conditions and the magnitude of response differed according to cultivar.


2000 ◽  
Vol 12 (2) ◽  
pp. 166-180 ◽  
Author(s):  
GUILLERMO SEIJO

Changes in cell water relations during precultures were followed in an attempt to understand the mechanism of cell hardening for cryopreservation by vitrification. Medium containing 0.4 M sucrose (psiw=-1.45 MPa) and containing 5 mg L-1 of ABA (MT psiw=-0.73 MPa and MS psiw=-0.48 MPa) were used to harden cell suspensions of orange and carrot. Preculture in these medium did not cause a significant decrease of cell viability, however, it improved the cell survival to PVS2 and liquid nitrogen expositions. When cells were inoculated into medium containing 0.4 M sucrose, the cell psiw decreased rapidly until reach the medium psiw , and turgor was also severely reduced or disappeared. Subsequently, cell psis began to decrease and after 48 h of treatment in low water potential medium, turgor was recovered by osmoregulation to almost the same values that cells had at the beginning of the experiment. Preculture in medium containing ABA also caused a decrease of cell psis but in much less extent than the preculture in low water potential medium. Since both precultures improved significantly the survival to PVS2 pretreatment and to LN exposure, this increment of survival to osmotic shock and vitrification can not be attribute solely to quantitative solute accumulation. The results suggest that qualitative accumulation of determined solutes would be the events which contributed for the improvement of tolerance to PVS2 exposure and thence tolerance to liquid nitrogen.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hiroshi Wada ◽  
Keisuke Nakata ◽  
Hiroshi Nonami ◽  
Rosa Erra-Balsells ◽  
Miho Tatsuki ◽  
...  

AbstractWatercore is a physiological disorder in apple (Malus × domestica Borkh.) fruits that appears as water-soaked tissues adjacent to the vascular core, although there is little information on what exactly occurs at cell level in the watercored apples, particularly from the viewpoint of cell water relations. By combining picolitre pressure-probe electrospray-ionization mass spectrometry (picoPPESI-MS) with freezing point osmometry and vapor pressure osmometry, changes in cell water status and metabolisms were spatially assayed in the same fruit. In the watercored fruit, total soluble solid was lower in the watercore region than the normal outer parenchyma region, but there was no spatial difference in the osmotic potentials determined with freezing point osmometry. Importantly, a disagreement between the osmotic potentials determined with two methods has been observed in the watercore region, indicating the presence of significant volatile compounds in the cellular fluids collected. In the watercored fruit, cell turgor varied across flesh, and a steeper water potential gradient has been established from the normal outer parenchyma region to the watercore region, retaining the potential to transport water to the watercore region. Site-specific analysis using picoPPESI-MS revealed that together with a reduction in turgor, remarkable metabolic modifications through fermentation have occurred at the border, inducing greater production of watercore-related volatile compounds, such as alcohols and esters, compared with other regions. Because alcohols including ethanol have low reflection coefficients, it is very likely that these molecules would have rapidly penetrated membranes to accumulate in apoplast to fill. In addition to the water potential gradient detected here, this would physically contribute to the appearance with high tissue transparency and changes in colour differences. Therefore, it is concluded that these spatial changes in cell water relations are closely associated with watercore symptoms as well as with metabolic alterations.


2013 ◽  
Vol 35 (3) ◽  
pp. 316-322 ◽  
Author(s):  
Welison Andrade Pereira ◽  
Sara Maria Andrade Pereira ◽  
Denise Cunha Fernandes dos Santos Dias

Germination is a biological process that depends on adequate water supply to embryo development. Water deficit slows this process and depending on intensity and extent of this deficit may cause seed death. Nevertheless, it has not yet been reported whether seed size influences physiological potential, or tolerance to water stress. This study aimed at assessing the effects of seed size, as well as of water stress on germination of the seeds and on early soybean seedling development. The experiment was composed by seeds of 10 soybean cultivars classified by metallic screens with three sizes of oval holes (S12, S13 and S14) and subjected to three water potentials (0, -0.1, and -0.2 MPa), with four replications. Data on genotypes were grouped as replications and arranged on a factorial 3 x 3 (size x water potential), with 40 replications. Data assessed were: first and final count of germination; length and seedling dry weight; and correlation between length/mass of radicle and hypocotyl. It was concluded that under ideal moisture conditions larger seeds have better physiological quality, producing more vigorous seedlings; but, that under water potential of -0.2 MPa smaller seeds produce larger seedlings; and that the hypocotyl is more influenced by water stress than the radicle.


1996 ◽  
Vol 26 (11) ◽  
pp. 1922-1933 ◽  
Author(s):  
John E. Major ◽  
Kurt H. Johnsen

Gas exchange and water potential were measured in 22-year-old black spruce (Piceamariana (Mill.) BSP) trees from four full-sib families on two sites (one drier and one wetter) at the Petawawa National Forestry Institute, Ontario. Based on an observed genotype × environment interaction and earlier work with seedlings, a hypothesis was formed that at high soil moisture availability, no genetic differences in net photosynthesis (Pn) would exist and as soil moisture decreases, genetic differences in Pn would increase. From results of initial research with mature trees we formed an alternative hypothesis that genetic differences in Pn are constantly maintained under an array of soil moisture conditions. The two models were rigorously tested over a range of soil moisture conditions using two physiological measurement crews who switched sites throughout the day. Second-year foliage Pn of mature black spruce was more affected by nonstomatal limitations than by stomatal limitations. Progeny of one female had 12.5% and 7.4% higher Pn than progeny of another female on the dry and wet site, respectively. Genetic variation in Pn was consistent over a range of soil water potential. Thus, the first hypothesis was rejected in favor of the alternative hypothesis. Genetic variation in Pn appeared to be due to differential response to vapor pressure deficit. Suggestions as to how to reconcile the observed genotype × environment interaction in growth with the genetic differences in Pn are discussed.


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