Effects of water potential on germination of lettuce, sunflower, and citrus seeds

1969 ◽  
Vol 47 (11) ◽  
pp. 1761-1764 ◽  
Author(s):  
Merrill R. Kaufmann
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Water Potential ◽  
Cellulose Acetate Membrane ◽  
Lettuce Seeds ◽  
Water Potentials ◽  
Citrus Seeds ◽  
Germinating Seeds ◽  
Polyethylene Glycol 6000 ◽  
Selection Of

The effect of nearly constant water potential on germination of citrus, sunflower, and lettuce seeds was studied. Water potential equilibration was achieved by placing soil above a cellulose acetate membrane which was in contact with a solution of polyethylene glycol-6000. Selection of solute potentials in the solution resulted in controlled water potentials in the soil over a range of 0 to −14.9 bars for citrus and 0 to −8.0 bars for sunflower and lettuce. The water stress experienced by germinating seeds in this system is largely the result of a matric effect rather than a solute effect.Citrus seeds germinated at water potentials as low as −4.7 bars and lettuce at −4.1 bars, but sunflower germinated at −8.0 bars. Sunflower germinated as rapidly at −4.1 bars as lettuce at −2.3 bars, both reaching 50% germination at about 8 days. Citrus germinated much more slowly, requiring 26 days at 0 bars.

scholarly journals Effects of Water Stress on Germination of Yarrow Populations (Achillea Spp.) From Different Bioclimatic Zones in Iran

2014 ◽  
Vol 68 (1) ◽  
pp. 39-54 ◽  
Author(s):  
Parvin Salehi Shanjani ◽  
Masoumeh Izadpanah ◽  
Mohamad Reza Mohamadpour
Keyword(s):  
Polyethylene Glycol ◽  
Natural Selection ◽  
Water Stress ◽  
Water Potential ◽  
Wild Populations ◽  
Genetic Potential ◽  
Intraspecific Variations ◽  
Germination Ability ◽  
Genetic Pool ◽  
Polyethylene Glycol 6000

ABSTRACT The effects of water potential on germination were studied in 18 wild populations of three yarrow species (Achillea tenuifolia, A. vermicularis and A. filipendulina) from different bioclimatic zones in Iran. Water potential between 0 and -0.6 MPa were obtained using polyethylene glycol 6000 (PEG-6000) solutions. The study of water stress on germination showed that, regardless of the species and the populations, the lowering of the water potential reduced the capacity for germination and early seeding growth. These results indicated a strong genetic potential for drought tolerance during germination within each species. These differences in germination ability of wild populations of each species might be attributed to intraspecific variations resulting from the effects of natural selection and genetic pool background.

Corrigenda - Measurement of the total water potential of aqueous solutions of polyethylene glycol - A comparison between osmometer, thermocouple psychrometer and equilibrated soil cores

Soil Research ◽  
1993 ◽  
Vol 31 (1) ◽  
pp. 1
Author(s):  
IM Wood ◽  
IK Dart ◽  
HB So
Keyword(s):  
Polyethylene Glycol ◽  
Water Potential ◽  
Close Correlation ◽  
Ease Of Use ◽  
Effect Of Temperature ◽  
Soil Cores ◽  
Total Water ◽  
Matric Potential ◽  
Thermocouple Psychrometer ◽  
Water Potentials

This study examined two polyethylene glycol (PEG) polymers (PEG 6000 and PEG 10000) and compared measurements of water potential obtained with a thermocouple osmometer and thermocouple psychrometers at three temperatures (15, 25 and 35�C) and five osmdalities (50, 100, 200, 300 and 400 g/1000 g water). These were then compared with estimates of matric potential of three soils brought to equilibrium with PEG solutions of the same osmolalities. At the same osmolality and temperature the two PEG polymers gave essentially the same water potential. There was a significant effect of temperature on water potential which corresponded closely with changes in specific gravity of the PEG solution. There was a close correlation between the measurements of water potential of the PEG solutions obtained with the osmometer and the psychrometers (R = 0.99). However, the psychrometer gave increasingly lower values than the osmometer as water potential decreased. The differences in the measurements between the two methods are thought to be the result of design and calibration differences. The ease of use of the osmometer is such that it is recommended for routine use. The water potentials of the soil cores brought to equilibrium with the PEG 10 000 solution were linearly related to the water potentials of the PEG solutions estimated from both the osmometer and psychrometers (R2 = 0.84). However, there were clear deviations from a 1:l relationship. It was concluded that the results from the soil cores could not be used to determine which of the two instruments gave the more accurate measurement of water potential of PEG solutions.

Effect of Water Stress on Stomatal Conductance and Leaf Water Relations of Leaves Along Current-Year Branches of Peach

1989 ◽  
Vol 16 (6) ◽  
pp. 549 ◽  
Author(s):  
SL Steinberg ◽  
MJ Mcfarland ◽  
JC Miller
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Water Status ◽  
Stomatal Closure ◽  
Water Flux ◽  
Leaf Water ◽  
Leaf Water Status ◽  
Mature Leaves ◽  
Water Potentials

A gradation, that reflects the maturity of the leaves, exists in the leaf water, osmotic and turgor potential and stomatal conductance of leaves along current and 1-year-old branches of peach. Predawn leaf water potentials of immature folded leaves were approximately 0.24 MPa lower than mature leaves under both well-watered and dry conditions. During the daytime the leaf water potential of immature leaves reflected the water potential produced by water flux for transpiration. In well- watered trees, mature and immature unfolded leaves had a solute potential at least 0.5 MPa lower than immature folded leaves, resulting in a turgor potential that was approximately 0.8 MPa higher. The turgor requirement for growth appeared to be much less than that maintained in mature leaves. As water stress developed and leaf water potentials decreased, the osmotic potential of immature folded leaves declined to the level found in mature leaves, thus maintaining turgor. In contrast, mature leaves showed little evidence of turgor maintenance. Stomatal conductance was lower in immature leaves than in fully mature leaves. With the onset of water stress, conductance of mature leaves declined to a level near that of immature leaves. Loss of turgor in mature leaves may be a major factor in early stomatal closure. It was concluded that osmotic adjustment played a role in maintenance of a leaf water status favorable for some growth in water-stressed immature peach leaves.

scholarly journals Effect of water stress induced by polyethylene glycol 6000 on the somatic embryos conversion into whole plantlets in cocoa (Theobroma cacao L.)

2021 ◽  
Vol 15 (1) ◽  
pp. 12-25
Author(s):  
Tokpapon Eliane Manlé ◽  
Kan Modeste Kouassi ◽  
Brahima André Soumahoro ◽  
Tchoa Koné ◽  
Kouablan Edmond Koffi ◽  
...  
Keyword(s):  
Climate Change ◽  
Polyethylene Glycol ◽  
Water Stress ◽  
Somatic Embryos ◽  
Stem Length ◽  
Improvement Program ◽  
Polyethylene Glycol 6000 ◽  
Regenerated Plantlets ◽  
Theobroma Cacao L

Rainfall scarcity due to climate change is a major constraint that limits cocoa productivity in Côte d'Ivoire. This work aims to regenerate cocoa plants tolerant to water stress using in vitro methods. Staminode and petal explants of the genotypes C1, C9, C14, C15, C16, C18 and C20 were used to produce somatic embryos through two methods. Firstly, somatic embryos were induced under stressfull conditions on media containing different concentrations of polyethylene glycol (PEG) 6000 (0; 25; 50; 75; 100 and 125 g/l) and secondly; under non-stressed conditions. Somatic embryos were placed on a conversion medium in the same stress condition. The number of regenerants decreased with the increase in the concentration of PEG with all genotypes. Only genotypes C1 and C15 regenerated plantlets under water stress conditions. The sensitive genotypes C9, C14, C16, C18 and C20 have not developed plantlets on media containing PEG. The plantlets produced under water deficit conditions exhibited a reduction in stem length and leaves number and an increase in length or offset of the high number of roots. The survival rate of regenerants during acclimatization was higher on the sandsubstrate. The selected genotypes could be used in an improvement program of cocoa production.Keywords: Climate change; plant regeneration; genotype; tolerance; drought; in vitro

The effect of ecological disturbance on competition between Crinipellis perniciosa and other tropical fungi

1988 ◽  
Vol 94 ◽  
pp. 159-166 ◽  
Author(s):  
Elizabeth Bravo-Velasquez ◽  
John Hedger
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Tropical Forests ◽  
Water Availability ◽  
Tropical Fungi ◽  
Soil Horizons ◽  
Ecological Disturbance ◽  
Crinipellis Perniciosa ◽  
Water Potentials

SynopsisIsolates of the tropical fungus Crinipellis perniciosa obtained from cocoa and lianas in Ecuador were grown on media ranging from −0.45 MPa to −9.0 MPa water potential and their responses compared to those of other agarics and Xylaria species isolated from cocoa. Antagonism between mycelia of C. perniciosa and these isolates was also assessed over the same range of water potentials. It is hypothesised that C. perniciosa and other canopy inhabiting fungi of tropical forests are adapted to water stress, but are not competitive with fungi which colonise later, following litterfall, from lower litter and soil horizons, where water availability is higher. Xylaria spp. proved to be aggressive antagonists of C. perniciosa over a range of water potentials.

scholarly journals Water stress in germination, growth and development of coffee cultivars

2018 ◽  
Vol 40 (1) ◽  
pp. 82-89 ◽  
Author(s):  
Julieta Andréa Silva de Almeida ◽  
Mary Túlia Vargas Lobato Guedes de Azevedo ◽  
Marcus Vinicius Salomon ◽  
Priscila Fratin Medina
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Seed Germination ◽  
Growth And Development ◽  
Coffea Arabica ◽  
Primary Root ◽  
Control Treatment ◽  
Effect Of Water ◽  
Reduced Height ◽  
Polyethylene Glycol 6000

Abstract: The aim of this study was to evaluate the effect of water stress on the germination of Coffea arabica seeds and the growth and development of plants from these seeds. Seeds of the cultivars Bourbon Vermelho, Mundo Novo, and BA-10 were placed to germinate in the dark at 30 ºC in the presence and absence of 100 g/L of polyethylene glycol 6000. The water stress applied delayed the beginning of seed germination by seven days in relation to seeds of the control, which had achieved responses of up to 50%, but there were no differences between the treatments at the end of the experiment. Furthermore, the length of the primary root in seeds germinated under water stress was less than in the control treatment, especially for the cultivar Mundo Novo. Plants of the cultivars Bourbon Vermelho and Mundo Novo developed from seeds previously germinated under water stress exhibited reduced height and fewer leaf pairs than those from the control, whereas ‘BA-10’ responded in a similar way in both treatments. Thus, the cultivars Bourbon Vermelho and Mundo Novo were more sensitive to the water stress applied in the germination phase than ‘BA-10’.

Measurement of the total water potential of aqueous solutions of polyethylene glycol - A comparison between osmometer, thermocouple psychrometer and equilibrated soil cores

Soil Research ◽  
1993 ◽  
Vol 31 (1) ◽  
pp. 1 ◽  
Author(s):  
IM Wood ◽  
IK Dart ◽  
HB So
Keyword(s):  
Polyethylene Glycol ◽  
Water Potential ◽  
Close Correlation ◽  
Ease Of Use ◽  
Effect Of Temperature ◽  
Soil Cores ◽  
Total Water ◽  
Matric Potential ◽  
Thermocouple Psychrometer ◽  
Water Potentials

This study examined two polyethylene glycol (PEG) polymers (PEG 6000 and PEG 10000) and compared measurements of water potential obtained with a thermocouple osmometer and thermocouple psychrometers at three temperatures (15, 25 and 35�C) and five osmdalities (50, 100, 200, 300 and 400 g/1000 g water). These were then compared with estimates of matric potential of three soils brought to equilibrium with PEG solutions of the same osmolalities. At the same osmolality and temperature the two PEG polymers gave essentially the same water potential. There was a significant effect of temperature on water potential which corresponded closely with changes in specific gravity of the PEG solution. There was a close correlation between the measurements of water potential of the PEG solutions obtained with the osmometer and the psychrometers (R = 0.99). However, the psychrometer gave increasingly lower values than the osmometer as water potential decreased. The differences in the measurements between the two methods are thought to be the result of design and calibration differences. The ease of use of the osmometer is such that it is recommended for routine use. The water potentials of the soil cores brought to equilibrium with the PEG 10 000 solution were linearly related to the water potentials of the PEG solutions estimated from both the osmometer and psychrometers (R2 = 0.84). However, there were clear deviations from a 1:l relationship. It was concluded that the results from the soil cores could not be used to determine which of the two instruments gave the more accurate measurement of water potential of PEG solutions.

Low-temperature scanning electron microscopic observations on endosperm in imbibed and germinated lettuce seeds

1998 ◽  
Vol 76 (3) ◽  
pp. 509-516 ◽  
Author(s):  
J Nijsse ◽  
E Erbe ◽  
NBM Brantjes ◽  
JHN Schel ◽  
W P Wergin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyethylene Glycol ◽  
Low Temperature ◽  
Lactuca Sativa ◽  
Electron Microscopic ◽  
Lettuce Seeds ◽  
Temperature Scanning ◽  
Germinating Seeds ◽  
Scanning Electron

Lettuce (Lactuca sativa L.) seeds were observed using low-temperature scanning electron microscopy (LTSEM). The structure of imbibing and germinating seeds was characterized and compared with that of seeds in which these processes were inhibited by high temperature, far-red irradiation, or polyethylene glycol. Germination is not associated with general breakdown or digestion of the entire endosperm at the micropylar region. Embryos of seeds imbibed in polyethylene glycol, which inhibited germination, appeared to lack turgor and were not able to emerge from the endosperm. Thermal or far-red inhibitory treatments were associated with the appearance of complex membraneous structures in cells of the endosperm and the embryo.Key words: endosperm, germination, Lactuca sativa, lettuce, low temperature scanning electron microscopy, seed.

Accumulation of polyethylene glycol 6000 and its effects on water content and carbohydrate level in water-stressed tomato plants

1988 ◽  
Vol 66 (5) ◽  
pp. 970-973 ◽  
Author(s):  
E. Jacomini ◽  
A. Bertani ◽  
S. Mapelli
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Soluble Sugar ◽  
Physiological Effects ◽  
Tomato Plants ◽  
Peg 6000 ◽  
Plant Parts ◽  
Tomato Roots ◽  
Peg Treatment ◽  
Polyethylene Glycol 6000

Young tomato plants were grown in 10 or 25% polyethylene glycol (PEG) 6000 solutions to impose water stress. Plant organs were analyzed to ascertain whether the various plant parts accumulated PEG and to determine the physiological effects. PEG 6000 was taken up by tomato roots and translocated to the shoots. PEG accumulation was greater in roots and in the first leaves and negligible in apical leaves. In all leaves there was an increase in soluble-sugar concentration during the PEG treatment. However, PEG-accumulating leaves showed a delay in dehydration in comparison with leaves where PEG was not accumulated. To explain this behaviour we hypothesize that PEG was accumulated in extracellular spaces and that, as a consequence, water was drawn out from the cells, inducing cellular but not tissue dehydration.

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