Effects of Light, Temperature and Osmotic Stress on Seed Germination of Eucalyptus occidentalis Endl

1975 ◽  
Vol 23 (3) ◽  
pp. 391 ◽  
Author(s):  
Y Zohar ◽  
Y Waisel ◽  
R Karschon
Keyword(s):  
Seed Germination ◽  
Osmotic Stress ◽  
Osmotic Potential ◽  
Continuous Light ◽  
Decisive Factor ◽  
Temperature Optimum ◽  
Dark Stress ◽  
Osmotic Potentials ◽  
Eucalyptus Occidentalis ◽  
Effect Of Light

Seed germination of E. occidentalis was examined under different combinations of light, temperature and osmotic potential. The effects of all three factors were found to be interrelated. Germination rates are directly related to the temperature of the environment between 15 and 30�C and to the osmotic potentials of the medium between -9.1 and 0 bars. The relative require- ment for light, i.e. the ratio of light germination to dark germination, increases with the rise in temperature. Light is a decisive factor in improving germination under osmotic stress; its effect is directly related to the intensity of stress. In media with an osmotic potential of -9.1 bars, the effect of light on germination is directly related to temperature. Optimum germination occurs at 30" under continuous light and under no osmotic styes. Very low germination is obtained under the same temperature in the absence of light and in a medium with an osmotic potential of -9.1 bars. Inhibition of germination caused by osmotic stress is 2-3 times as great as that caused by dark stress. Seed germination was found to vary according to an annual rhythm. Lower rates of germination were obtained in July and January, whereas maximum germination occurred from March to May.

Comparison of the effects of the physical and chemical components of soil water energy on seed germination

1962 ◽  
Vol 13 (4) ◽  
pp. 575 ◽  
Author(s):  
N Collis-George ◽  
JE Sands
Keyword(s):  
Free Energy ◽  
Soil Moisture ◽  
Seed Germination ◽  
Osmotic Potential ◽  
Chemical Components ◽  
Matric Potential ◽  
Experimental Procedure ◽  
Germination Behaviour ◽  
Physical And Chemical ◽  
Osmotic Potentials

The components of total soil moisture energy of consequence to a biological system are matric potential and osmotic potential. An experimental procedure, which allows the effects of the potentials to be considered independently, is described and discussed. Germination behaviour does not support the hypothesis that matric and osmotic potentials should have similar biological consequences because their free energy measurements are identical. The results support a diffusion phenomenon hypothesis with movement of solute from the soil solution through the cell membranes, so that any biological consequence is that of an internal "toxicity" rather than an osmotic "drought". For some osmotic systems, 100 cm of matric potential is as effective as 10 000 cm of osmotic potential in retarding seed germination rates.

Effects of temperature, salt, and osmotic potential on early growth of wheat (Triticum aestivum). I. Germination

1990 ◽  
Vol 68 (3) ◽  
pp. 524-528 ◽  
Author(s):  
Cheryl R. Hampson ◽  
G. M. Simpson
Keyword(s):  
Osmotic Stress ◽  
Osmotic Potential ◽  
Germination Rate ◽  
Early Growth ◽  
Percent Germination ◽  
Effects Of Temperature ◽  
Sulfate Salts ◽  
Time To Onset ◽  
Main Effects ◽  
Osmotic Potentials

Kernels of spring wheat (cv. Katepwa) were germinated in Petri dishes at six osmotic potentials (−0.3 to −1.8 MPa) and eight temperatures (6–34 °C) in single-salt solutions of a variety of chloride and sulfate salts, and the time to onset of germination, germination rate index, and final percent germination were determined. Percent germination was maximal at 18–22 °C in the presence of osmotic stress, but was unaffected by temperature in its absence. At temperatures below 10 °C or above 30 °C and osmotic potentials below −0.3 MPa, germination was delayed, slowed down, and eventually inhibited. Temperature stress intensified the effects of osmotic stress on germination and vice versa. Main effects of temperature, osmotic potential, and salt type and all their interactions were highly significant (P < 0.01) for all variables.

scholarly journals Seed Germination of Four Lupine Species under Differing Osmotic Condition

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 476D-476
Author(s):  
Wayne A. Mackay ◽  
Tim D. Davis
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
The Other ◽  
West Texas ◽  
Desert Species ◽  
Petri Dishes ◽  
Peg 8000 ◽  
Osmotic Potentials

Seeds of four lupine species (L. microcarpus var. aureus, L. havardii, L. succulentis, and L. texensis) were subjected to 0, –2, –4, –6, or –8 bars osmotic potential using PEG 8000 solutions. Seeds of all species were acid scarified prior to placement in petri dishes containing the osmotic solutions. Petri dishes were placed in a seed germination chamber at 25°C with germination data collected daily for 15 days. Seeds of L. havardii, a desert species native to west Texas exhibited the greatest germination as osmotic potential declined while L. succulentis, a species adapted to moist sites, exhibited the greatest decline in germination as osmotic potential decreased. The other species exhibited intermediate germinability under the lower osmotic potentials.

scholarly journals Effects of drought stress on germination and seedling growth of different field pea varieties

2021 ◽  
pp. 59-70
Author(s):  
Gordana Petrovic ◽  
Tomislav Zivanovic ◽  
Radmila Stikic ◽  
Zorica Nikolic ◽  
Dusica Jovicic ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Stress ◽  
Seedling Growth ◽  
Germination Percentage ◽  
Field Pea ◽  
Tolerance Index ◽  
Germination Time ◽  
Mean Germination Time ◽  
Effects Of Drought ◽  
Osmotic Potentials

Germination and seedling growth of seven genotypes of field pea (Pisum sativum L.) were studied in PEG-6000 solution having osmotic potentials -0.1 and -0.2 MPa. A study was undertaken to evaluate the influence of different osmotic potentials (MPa) on seed germination percentage (GP) and mean germination time (MGT). Results show that the percentage of germination decreased with a decrease in osmotic potential, while mean germination time increased. Variety Javor is much more sensitive than the other varieties at all levels of osmotic stress. By contrast, the lowest sensitivity of germination and MGT was found in varieties Mraz and Trezor. Seed germination tests at -0.1 to -0.2 MPa have the potential to be used as tests in field pea. Osmotic stress exposure and its duration significantly affected the growth of seedlings (shoot and root) and the accumulation of biomass, while its effect was more prominent on the growth of the shoot than on root growth, which was also confirmed by the root tolerance index.

scholarly journals Seed Germination and Initial Growth of Quinoa Seedlings Under Water and Salt Stress

2019 ◽  
Vol 11 (15) ◽  
pp. 153 ◽  
Author(s):  
Geovana Facco Barbieri ◽  
Raquel Stefanello ◽  
Janine Farias Menegaes ◽  
Janete Denardi Munareto ◽  
Ubirajara Russi Nunes
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Chenopodium Quinoa ◽  
Dry Mass ◽  
Germination Percentage ◽  
Initial Growth ◽  
Peg 6000 ◽  
Germination Process ◽  
Seedling Length ◽  
Osmotic Potentials

Excessive amounts of salts and soil water deficiency interfere on seed germination and the full development of several crops. The objective of this research was to evaluate the effect of water stress and salinity on the germination process and initial growth of quinoa (Chenopodium quinoa Willd.) seedlings. In the first experiment, two quinoa seed lots with different physiological conditions were distributed on paper soaked in aqueous solution containing polyethylene glycol PEG-6000 in osmotic potentials corresponding to 0.0; -0.1; -0.2; -0.3 and -0.4 MPa and held at 20 &deg;C under 8 hours of light exposition. In the second experiment, solutions of sodium chloride (NaCl), potassium chloride (KCl), calcium chloride (CaCl2) and magnesium chloride (MgCl2) were used to simulate the effect of salinity using the osmotic potentials, temperature and light conditions previously described. Assessed parameters were the germination percentage, first count, length and dry mass of seedlings. There was a reduction in quinoa germination percentage, first seed count and seedling length as the osmotic potential decreased in CaCl2, NaCl, KCl, MgCl2 and PEG-6000 solutions. The quinoa seeds exhibited higher tolerance to NaCl and KCl salts in the germination process and initial seedling growth. The progressive reduction of the osmotic potential induced by salts NaCl, KCl, CaCl2, MgCl2 and PEG-6000 negatively affects seed germination and initial growth of quinoa seedlings.

Germination, Emergence, and Seedling Establishment of Buffalo Gourd (Cucurbita foetidissima)

Weed Science ◽  
1994 ◽  
Vol 42 (3) ◽  
pp. 358-363 ◽  
Author(s):  
Michael J. Horak ◽  
Jonathan K. Sweat
Keyword(s):  
Seed Germination ◽  
Seedling Establishment ◽  
Osmotic Potential ◽  
Seedling Emergence ◽  
Buffalo Gourd ◽  
Osmotic Potentials

Studies were conducted to determine the effects of scarification, temperature, osmotic potential, and pH on seed germination of buffalo gourd and to examine seedling emergence and establishment. Mechanical and chemical scarification did not increase germination compared to non-scarified seed. Seed germinated at constant temperatures in the dark from 15 to 37 C with optimum germination at 25 C. As osmotic potentials became more negative from −0.1 to −0.8 MPa, germination decreased from 77 to 53%. Germination increased from 15% at pH 2.2 to 90% at pH 8. Seedlings were able to emerge from depths as great as 12 cm, and plants younger than 19 d were not able to sprout from the roots when the shoots were removed.

scholarly journals Mobilization of reserves and germination of seeds of Erythrina velutina Willd. (Leguminosae - Papilionoideae) under different osmotic potentials

2012 ◽  
Vol 34 (4) ◽  
pp. 580-588 ◽  
Author(s):  
Renata Conduru Ribeiro Reis ◽  
Bárbara França Dantas ◽  
Claudinéia Regina Pelacani
Keyword(s):  
Water Stress ◽  
Seed Germination ◽  
Osmotic Potential ◽  
Soluble Sugars ◽  
Germination Percentage ◽  
Uniformity Coefficient ◽  
Carbon And Nitrogen ◽  
Germination Process ◽  
Mean Time ◽  
Osmotic Potentials

Some environmental factors, including water availability, may influence seed germination. This study investigated the germination of E. velutina seeds submitted to different osmotic potentials and mobilization of reserves during water-stress. Scarified seeds were arranged in paper rolls and soaked in solutions of Polyethylene Glycol (PEG) prepared in osmotic potentials 0.0, -0.2, -0.4, -0.6, and -0.8 MPa and kept into a seed germinator, at 25 °C, and 12/12 h photoperiod (L/D), during 10 days. The percentage, mean time, mean speed, germination speed index; as well as the germination uniformity coefficient were assessed. During germination process the total soluble sugars, reducing sugars, soluble protein, and total amino acids were quantified in the cotyledon, hypocotyl and radicle of soaked seeds and cotyledons of quiescent seeds (control). There was influence of osmotic potential on E. velutina seed germination. The germination percentage remained at high levels until -0.6 MPa and above this osmotic potential there has been no germination. The mobilization of stored reserves of carbon and nitrogen in E. velutina seeds was also influenced by water-stress. There was sensitiveness between -0.2 and -0.6 MPa; however, the degradation and the mobilization of reserves was slower when the osmotic potential decreased.

Influence of soil moisture regime on the respiration response of soils subjected to osmotic stress

Soil Research ◽  
1989 ◽  
Vol 27 (1) ◽  
pp. 161 ◽  
Author(s):  
GP Sparling ◽  
AW West ◽  
J Reynolds
Keyword(s):  
Soil Moisture ◽  
Microbial Biomass ◽  
Osmotic Stress ◽  
Respiration Rate ◽  
Osmotic Potential ◽  
Moisture Regime ◽  
Air Drying ◽  
Climatic Regions ◽  
Soil Moisture Regime ◽  
Osmotic Potentials

The influence of the soil moisture regime on the tolerance of the soil micro-organisms to increased osmotic stress was examined by laboratory tests with a range of New Zealand soils. Soils from various climatic regions (moist, intermediate and dry) were amended with glucose-NaCl solutions, incubated for 0.5 h, and the respiration rate over the following 2 h was used as a measure of the response of the microbial biomass to the changed osmotic potential. Osmotic potentials were varied between -4 and -80 bar by altering the concentration of NaCl. Air-drying the soils at 25�C decreased the respiration response of the microbial biomass by 3-60% but had little effect on the tolerance of the surviving populations to decreased osmotic potentials. In general, the soils showed the same patterns: an osmotic potential of -23 bar decreased the respiration response by 28-45% (18-44% after air-drying) and a -80 bar potential decreased it by 64-86% (52-84% after air-drying). For the majority of soils, a consistent relationship was obtained between the respiration rate of the moist soils and the osmotic potential applied. A reasonable prediction of the respiration response after air-drying could be obtained from the respiration response of moist soils at -25 bar osmotic potential.

Seed-borne fungi of cowpea [Vigna unguiculata (L.) Walp] and their possible control in vitro using locally available fungicides in Botswana.

2016 ◽  
Vol 5 (11) ◽  
pp. 5016 ◽  
Author(s):  
K. B. Khare* ◽  
Loeto D. ◽  
Wale K. ◽  
Salani M.
Keyword(s):  
Seed Germination ◽  
Continuous Light ◽  
Sodium Hypochlorite Solution ◽  
Distilled Water ◽  
Percentage Germination ◽  
Department Of Agriculture ◽  
Hypochlorite Solution ◽  
Cowpea Cultivars ◽  
Petri Plate

Seeds of three cowpea cultivars namely Black eye, ER 7 and Tswana obtained from the Department of Agriculture Research, Gaborone were tested for the presence of seed-borne fungi, and their possible control in vitro using locally available fungicides. Four hundred fifty seeds of each cultivar of cowpea were disinfected with 2% sodium hypochlorite solution for 10 min and washed three times with sterile distilled water before placing them in PDA plates (5 seeds/9 cm Petri plate), incubated at 22±2o C for 12 hour each under continuous light and dark. A total of eight fungi were detected from seeds of cowpea. These were Aspergillus flavus, A. niger, Cylindrocarpon sp., Fusarium equisiti, F. oxyaporum, Penicillium chyrosogenum, Rhizopus oligosporus and R. stolonifer. Rhizopus spp. were dominant fungi recovered from seeds, followed by Penicillium, Aspergillus, Fusarium and Cylindrocarpon. The fungi detected resulted in decay and rotting of seeds, and thereby reducing percentage germination of seeds (22%, 37% and 63 % seed germination in Black eye, ER7 and Tswana varieties of cowpea respectively). Out of four fungicides tested, benlate, captan, dithane M 45 and chlorothalanil. Dithane M45 effectively controlled seed-borne fungi, and enhanced seed germination to an average of 86% (93% germination with no fungi detected in Tswana variety) as compared to chlorothalonile (79%), benlate and captan (77%) and un-treated seeds (45%). The fungal incidence was reduced to 2.3%, 4.3%, 5.3% and 5.3% when seeds were treated with dithane M-45, chlorothalonil, benlate and captan respectively as compared to 62% in non-treated seeds.

scholarly journals In vitro seed germination response of corn hybrids to osmotic stress conditions

age ◽  
2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Charles Hunt Walne ◽  
Annabeth Gaudin ◽  
W. Brien Henry ◽  
Kambham Raja Reddy
Keyword(s):  
Seed Germination ◽  
Osmotic Stress ◽  
Stress Conditions ◽  
Corn Hybrids ◽  
Germination Response
Sign in / Sign up

Export Citation Format

Share Document