Germination and Emergence of Longspine Sandbur (Cenchrus longispinus)

Weed Science ◽  
1989 ◽  
Vol 37 (1) ◽  
pp. 63-67 ◽  
Author(s):  
Rick A. Boydston
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Water Potential ◽  
Complete Darkness ◽  
Mesh Screen ◽  
Osmotic Potentials

Longspine sandbur germinated readily after 3 months of storage at 0 to 4 C. Germination was 15 to 82 and 10 to 76% for seed retained by or that passed through a 1.7-mm-mesh screen, respectively, and was greatest in complete darkness near 30 C. Light inhibited seed germination at most of the temperatures tested. Incubating imbibed seed at 40 C and 40/10 C for 3 weeks reduced the viability of seed that did not germinate by more than 50%. Primary seed within the bur germinated 77% and secondary seed germinated 35% during 2 weeks at 35/10 C (16 light/8 dark h). Primary seed placed in polyethylene glycol (PEG) solutions ranging from −0.5 to −1.5 kPa water potential germinated as much or greater than seed placed in water, while secondary seed germination was inhibited by similar osmotic potentials. Seedlings emerged from depths to 11 cm but emerged most readily from 1- to 3-cm depths.

scholarly journals Adaptive drought tolerance during germination of Salsola drummondii seeds from saline and nonsaline habitats of the arid Arabian deserts

Botany ◽  
2019 ◽  
Vol 97 (2) ◽  
pp. 123-133 ◽  
Author(s):  
Attiat Elnaggar ◽  
Ali El-Keblawy ◽  
Kareem A. Mosa ◽  
Teresa Navarro
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Light Regimes ◽  
Saline Habitats ◽  
Population Origin ◽  
Effects Of Temperature ◽  
Osmotic Potentials

The effects of temperature, light, salinity, and drought on germination of halophytes have been extensively studied. However, few studies have focused on the germination of plants that grow well in both saline and nonsaline habitats (i.e., habitat-indifferent halophytes). Here, we assess the impacts of population origin, temperature, and light on drought tolerance, as simulated with polyethylene glycol (PEG), during germination of Salsola drummondii Ulbr., a habitat-indifferent halophyte from the arid Arabian deserts. Seeds were collected from both saline and nonsaline habitats and germinated at six concentrations of PEG at three temperatures and two light regimes. An increase in the concentration of PEG resulted in a significant reduction in seed germination, especially at higher temperatures. Seeds from the nonsaline habitat attained significantly greater germination efficiency at concentrations of PEG up to –1.2 MPa, but there was no difference in germination of seeds between the two habitats at concentrations of –1.5 MPa. Seeds from the saline habitat germinated significantly faster at higher concentrations of PEG. Germination was significantly higher in darkness than in light at –1.5 MPa at the lower temperatures, but the opposite was true for the higher temperatures. Seeds from saline habitats had higher levels of dormancy and faster rates of germination at higher concentrations of PEG because of their adaptation to low osmotic potentials.

Germination, and Seedling and Rosette Development of Flodman Thistle (Cirsium flodmanii)

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 768-773 ◽  
Author(s):  
Robert G. Wilson ◽  
Melvin K. McCarty
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Water Potential ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Plant Water ◽  
Germination Medium ◽  
Water Potentials ◽  
Average Plant ◽  
Osmotic Potentials

Maximum germination of flodman thistle [Cirsium flodmanii(Rydb.) Arthur ♯3CIRFL] occurred at alternating temperatures of 10 to 20 and 20 to 30 C. Seeds germinated (20%) in 1.7 M NaCl. Light was important in seed germination; however, its absence could be overcome by adding 8.6 × 10-5M GA3(gibberellic acid) to the germination medium. The greatest seedling emergence occurred when seeds were planted on the soil surface and was lower when seeds were buried at any depth in the soil. Osmotic potentials at −0.5 MPa and greater reduced germination, but 3% of the seeds germinated at −1.3 MPa. Flodman thistle seedlings tolerated average plant water potentials of −0.9 and −1.1 MPa, but they died when the water potential was decreased to −1.5 MPa. Flodman thistle seedlings 43 days old and with four true leaves resprouted after topgrowth removal. Regrowth was evident on 75% of the clipped plants 13 days after initial topgrowth removal. Flodman thistle rosettes spread more rapidly and rosette survival was enhanced more in a weed-free nursery than in a weedy pasture.

scholarly journals Influence of priming on Eucalyptus spp seeds' tolerance to salt stress

2016 ◽  
Vol 38 (4) ◽  
pp. 329-334 ◽  
Author(s):  
Anderson Cleiton José ◽  
Natália Cristina Nogueira Silva ◽  
José Marcio Rocha Faria ◽  
Wilson Vicente Souza Pereira
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Water Potential ◽  
Salt Solution ◽  
Germination Percentage ◽  
Eucalyptus Urophylla ◽  
Nacl Solution ◽  
Peg 6000 ◽  
Germination Speed ◽  
Osmotic Potentials

Abstract: The objective of this experiment was to evaluate the effect of priming on the germination of Eucalyptus urophylla and of hybrid E. urophylla × E. grandis seeds under salt stress. Two osmotic potentials (-1.0 and -1.5 MPa) were tested, using PEG 6000 for 1 and 3 days. After priming, seeds were germinated under salt stress in a NaCl solution at 0.0 (control), -0.5, -0.75 and -1.0 MPa potentials, at 25 °C. Seed germination and germination speed index decreased as the water potential of the germination medium decreased. However, E. urophylla was more tolerant to salt stress; it showed a higher germination percentage under all tested potentials, when compared to the hybrid. The osmotic conditioning at -1.0 MPa for three days was more effective when E. urophylla x E. grandis was germinated in a salt solution at -1.0 MPa, indicating that this treatment was more effective in inducing tolerance to salt stress.

Effects of Osmotica Around the Roots on Water Uptake by Maize Plants

1980 ◽  
Vol 7 (1) ◽  
pp. 27 ◽  
Author(s):  
RA Nulsen ◽  
GW Thurtell
Keyword(s):  
Polyethylene Glycol ◽  
Water Potential ◽  
Nutrient Solution ◽  
Leaf Water Potential ◽  
Flow Rate ◽  
Osmotic Potential ◽  
Leaf Water ◽  
Maize Plants ◽  
The Difference ◽  
Osmotic Potentials

Nutrient solutions with osmotic potentials of -70, -190 and -380 kPa were supplied to maize plants whose roots were enclosed in a pressure chamber. The plants were stressed and then rewatered with the same nutrient solution. Sap flow rate from the detopped root system was measured at 400 kPa applied pressure. The lower was the osmotic potential of the pretreatment solution, the lower was the initial flow rate. Flow rates rapidly decreased to zero and did not recover for up to 90 min. Different responses in leaf water potential of unstressed, intact plants occurred when the nutrient solution bathing the root was replaced by either a more concentrated nutrient solution or a solution of sucrose or polyethylene glycol 6000. For nutrient solution replacement the change in leaf water potential was less than the difference in solution osmotic potentials; for sucrose the difference was greater, and for polyethylene glycol the change was equal to the osmotic potential difference. Osmotic effects observed were due to differential accumulations at different barriers in the root. The zero-flow periods seen during recovery of severely stressed plants may have been due to a decrease in the osmotic potential of the solution external to the plasmalemma of root cortical cells.

Osmotic and specific ion effects on the germination of alfalfa

1974 ◽  
Vol 52 (4) ◽  
pp. 803-808 ◽  
Author(s):  
R. E. Redmann
Keyword(s):  
Polyethylene Glycol ◽  
Sodium Chloride ◽  
Seed Germination ◽  
Sodium Sulfate ◽  
Potassium Sulfate ◽  
Specific Ion Effects ◽  
Ion Effects ◽  
Alfalfa Varieties ◽  
Sodium And Potassium ◽  
Osmotic Potentials

Inhibition of seed germination in alfalfa varieties Rambler, Roamer, and Beaver by iso-osmotic potentials of different substrates varied widely. Sodium and potassium sulfate and sodium chloride were most inhibitory. Chlorides of potassium and magnesium and magnesium sulfate were least effective; mannitol and polyethylene glycol were intermediate. Ion toxicity was determined by measuring germination recovery after treatment with solutions containing equivalent weights of salt. No salts were toxic at 25 meq/liter. Sodium sulfate and magnesium chloride appeared highly toxic at 200 meq/liter; other salts were less toxic, with sodium chloride showing the least effect of all. All salts were highly toxic at 400 meq/liter. Germination recovery after treatment with polyethylene glycol and mannitol was good, clearly distinguishing osmotic and specific ion effects. Variety Beaver was the most tolerant of both the osmotic and toxic effects of salt.

Seed germination of pitaya (Hylocereus spp.) as affected by seed extraction method, storage, germination conditions, germination assessment approach and water potential

2019 ◽  
Vol 33 (3) ◽  
pp. 372-394
Author(s):  
Dessireé Zerpa-Catanho ◽  
Andrés Hernández-Pridybailo ◽  
Viviana Madrigal-Ortiz ◽  
Adonay Zúñiga-Centeno ◽  
Carolina Porras-Martínez ◽  
...  
Keyword(s):  
Seed Germination ◽  
Water Potential ◽  
Extraction Method ◽  
Assessment Approach ◽  
Seed Extraction

scholarly journals Does discontinuous hydration of Senna spectabilis (DC.) H.S. Irwin & Barneby var. excelsa (Schrad.) H.S. Irwin & Barneby (Fabaceae) seeds confer tolerance to water stress during seed germination?

2018 ◽  
Vol 40 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Ayslan Trindade Lima ◽  
Paulo Henrique de Jesus da Cunha ◽  
Bárbara França Dantas ◽  
Marcos Vinicius Meiado
Keyword(s):  
Water Stress ◽  
Seed Germination ◽  
Stress Conditions ◽  
Hydration Time ◽  
Senna Spectabilis ◽  
Mean Germination Time ◽  
Polyethylene Glycol 6000 ◽  
Osmotic Potentials ◽  
Germination Parameters ◽  
Hydration And Dehydration

Abstract: Seed hydration memory is the ability of seeds to retain biochemical and physiological changes caused by discontinuous hydration. This study aimed to determine if Senna spectabilis (DC.) H.S. Irwin & Barneby var. excelsa (Schrad.) H.S.Irwin & Barneby (Fabaceae) present seed memory and evaluate the effects of hydration and dehydration cycles (HD) on the seed germination of this species when submitted to conditions of water stress. Seeds underwent HD cycles (0, 1, 2 and 3 cycles) corresponding to the hydration times X (6 hours), Y (16 hours) and Z (24 hours), determined from the imbibition curve, with 5 hours of dehydration and submitted to water stress conditions. Germination was evaluated at 0.0, -0.1, -0.3, -0.6 and -0.9 MPa, obtained with polyethylene glycol 6000 solution. Germinability (%), mean germination time (days) and hydrotime (MPa d-1) were calculated. The seeds of S. spectabilis var. excelsa are sensitive to the low osmotic potentials tested in this study, however, when submitted to the HD cycles of 16 hours hydration (time Y), the tolerance to water stress conditions is increased. In addition, the observed benefits on the evaluated germination parameters show that S. spectabilis var. excelsa present seed hydation memory.

Water potentials of seeds of Bromus inermis and Medicago sativa imbibed on media of various osmotic potentials

1976 ◽  
Vol 54 (17) ◽  
pp. 1997-1999 ◽  
Author(s):  
W. T. McDonough
Keyword(s):  
Polyethylene Glycol ◽  
Medicago Sativa ◽  
Bromus Inermis ◽  
Smooth Brome ◽  
Thermocouple Psychrometer ◽  
Water Potentials ◽  
The Media ◽  
Medicago Sativa L ◽  
Brome Grass ◽  
Osmotic Potentials

Seeds of smooth brome grass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L. cultivar Ladak) were allowed to imbibe in water or solutions of polyethylene glycol (Carbowax 1540), mannitol, or sodium chloride. Seed water potentials were determined over a 72-h period after transfer of seeds to thermocouple psychrometer chambers. Seed water potentials were lower than osmotic potentials of the media, but these two potentials were not clearly related to each other. Possible reasons for the lack of gradation in response are discussed.

scholarly journals Muskmelon seed germination and seedling development in response to seed priming

2003 ◽  
Vol 60 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
Seed Germination ◽  
Cucumis Melo ◽  
Germination Rate ◽  
Fungal Growth ◽  
Seed Priming ◽  
Seedling Development ◽  
Factors Affecting ◽  
Total Seed ◽  
Cucumis Melo L ◽  
Osmotic Potentials

Important factors affecting seed priming have not been extensively reported in muskmelon (Cucumis melo L.) studies. The optimization of the seed priming technique becomes very important at the commercial scale. Little information has been reported on seedling development of muskmelon subsequent to seed priming. Seeds of muskmelon were primed in darkness at 25°C in different solutions and three osmotic potentials. Seeds were also primed with and without aeration during different periods. In relation to osmotic solutions, an osmotic potential around -1.30 MPa is most adequate for muskmelon priming. Salt solutions gave better germination rate but were deleterious for seed germination, especially at higher osmotic potentials. Aeration of the soaking salt solution gave faster germination at 17°C, and because of the early germination, these treatments probably presented a better seedling development. Deleterious effect on total seed germination was observed for long soaking periods with aeration. Fungal growth increased on seeds primed in aerated solutions. Seeds from priming treatments had a better germination rate and seedling development under 17 and 25°C.

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