Effects of Temperature Fluctuation, Red and Far-Red Light and Nitrate on Seed Germination of Five Grasses

1983 ◽  
Vol 20 (3) ◽  
pp. 923 ◽  
Author(s):  
E. D. Williams
Keyword(s):  
Seed Germination ◽  
Temperature Fluctuation ◽  
Red Light ◽  
Effects Of Temperature

Effects of Temperature and Light Variations on Seed Germination in Sunflower(Helianthus)Species

Weed Science ◽  
1978 ◽  
Vol 26 (3) ◽  
pp. 277-280 ◽  
Author(s):  
A. M. Olivieri ◽  
S. K. Jain
Keyword(s):  
Seed Germination ◽  
Environmental Conditions ◽  
Red Light ◽  
Individual Plant ◽  
Germination Characteristics ◽  
Helianthus Species ◽  
Two Temperatures ◽  
Effects Of Temperature ◽  
Seed Characteristics ◽  
Helianthus Exilis

Some genetic and physiological aspects of seed germination of wild and weedy sunflowers were investigated in order to analyze their population differentiation in seed characteristics. Seed germination of six populations classified on the basis of morphology asHelianthus exilisGray,H. exilis-bolanderihybrids, andH. bolanderiGray was studied under red light at 20 C. The average germination of the three groups respectively were 56, 63, and 42%. Germinability of individual plant progenies derived from populations ofH. bolanderiandH. exiliswas studied under red and far-red light combined with the pretreatments at two temperatures (10 and 20 C). Average germination per progeny reached a maximum of 59% with red light and 10 C inH. bolanderi. Far-red light promoted germination ofH. bolanderibut was ineffective withH. exilis. The homogeneity of populations within each taxon and the fact that germinability differences among theH. bolanderiprogenies were consistent over replications, suggest a genetic component of variation. However, progenies obtained by crossing selected individuals that germinated under certain light and temperature treatments, were not significantly correlated in germinability with that of their parents. Inheritance of germination characteristics appears to be complex and highly dependent on the environmental conditions.

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.

scholarly journals The counteracting effect of potassium cyanide in sodium azide-inhibited germination of Paulownia tomentosa  Steud. seeds

2005 ◽  
Vol 57 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Suzana Zivkovic ◽  
Dragoljub Grubisic ◽  
Zlatko Giba ◽  
Radomir Konjevic
Keyword(s):  
Seed Germination ◽  
Light Pulse ◽  
Sodium Azide ◽  
Incubation Medium ◽  
Red Light ◽  
Potassium Cyanide ◽  
Inhibitory Effect ◽  
Escape Time ◽  
Paulownia Tomentosa ◽  
Respiratory Inhibitors

The effect of some respiratory inhibitors on light-induced Paulownia tomentosa Steud. seed germination was studied. Millimolar solution of sodium azide was sufficient to completely prevent germination induced by a 5-min red light pulse. The inhibitory effect of azide was absent if seeds were rinsed before phytochrome activation by light. Sodium azide was effective only if present in the period of Pfr activity. The escape time from azide inhibition compared to the escape from far-red light action, was delayed for about 24 hours. When azide was applied after phytochrome activation, its effect depended on how long it was present in the incubation medium. The removal of azide allowed full restoration of germination by another red light pulse and the far-red escape time did not differ from the escape of untreated, i.e. water-imbibed seeds. Potassium cyanide alone did not produce any effect in light-stimulated germination of these seeds. However, it counteracted the inhibitory effect of azide in light-stimulated germination, if applied simultaneously at a concentration three times higher.

scholarly journals Interactive Effects of Light Quality and Temperature on Arabidopsis Growth and Immunity

2020 ◽  
Vol 61 (5) ◽  
pp. 933-941
Author(s):  
Xiaoying Liu ◽  
Chunmei Xue ◽  
Le Kong ◽  
Ruining Li ◽  
Zhigang Xu ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Blue Light ◽  
Light Quality ◽  
Red Light ◽  
Complex Interaction ◽  
Hypocotyl Elongation ◽  
Interactive Effects ◽  
Phytochrome B ◽  
Light Conditions ◽  
Effects Of Temperature

Abstract We report here the interactive effects of three light qualities (white, red and blue) and three growth temperatures (16�C, 22�C and 28�C) on rosette growth, hypocotyl elongation and disease resistance in Arabidopsis thaliana. While an increase in temperature promotes hypocotyl elongation irrespective of light quality, the effects of temperature on rosette growth and disease resistance are dependent on light quality. Maximum rosette growth rate under white, red and blue light are observed at 28�C, 16�C and 22�C, respectively. The highest disease resistance is observed at 16�C under all three light conditions, but the highest susceptibility is observed at 28�C for white light and 22�C for red and blue light. Interestingly, rosette growth is inhibited by phytochrome B (PHYB) under blue light at 28�C and by cryptochromes (CRYs) under red light at 16�C. In addition, disease resistance is inhibited by PHYB under blue light and promoted by CRYs under red light. Therefore, this study reveals a complex interaction between light and temperature in modulating rosette growth and disease resistance as well as the contribution of PHYB and CRY to disease resistance.

scholarly journals Arabidopsis chloroplast J protein DJC75/CRRJ mediates nitrate-promoted seed germination in the dark

2020 ◽  
Vol 125 (7) ◽  
pp. 1091-1099
Author(s):  
Huai-Syuan Ciou ◽  
Yu-Lun Tsai ◽  
Chi-Chou Chiu
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Germination ◽  
Germination Rate ◽  
Red Light ◽  
Phytochrome B ◽  
Biosynthetic Gene ◽  
Unknown Mechanism ◽  
J Domain ◽  
Domain Protein ◽  
J Protein

Abstract Background and Aims Nitrate can stimulate seed germination of many plant species in the absence of light; however, the molecular mechanism of nitrate-promoted seed germination in the dark remains largely unclear and no component of this pathway has been identified yet. Here, we show that a plastid J-domain protein, DJC75/CRRJ, in arabidopsis (Arabidopsis thaliana) is important for nitrate-promoted seed germination in the dark. Methods The expression of DJC75 during imbibition in the dark was investigated. The seed germination rate of mutants defective in DJC75 was determined in the presence of nitrate when light cues for seed germination were eliminated by the treatment of imbibed seeds with a pulse of far-red light to inactivate phytochrome B (phyB), or by assaying germination in the dark with seeds harbouring the phyB mutation. The germination rates of mutants defective in CRRL, a J-like protein related to DJC75, and in two chloroplast Hsp70s were also measured in the presence of nitrate in darkness. Key Results DJC75 was expressed during seed imbibition in the absence of light. Mutants defective in DJC75 showed seed germination defects in the presence of nitrate when light cues for seed germination were eliminated. Mutants defective in CRRL and in two chloroplast Hsp70s also exhibited similar seed germination defects. Upregulation of gibberellin biosynthetic gene GA3ox1 expression by nitrate in imbibed phyB mutant seeds was diminished when DJC75 was knocked out. Conclusions Our data suggest that plastid J-domain protein DJC75 regulates nitrate-promoted seed germination in the dark by upregulation of expression of the gibberellin biosynthetic gene GA3ox1 through an unknown mechanism and that DJC75 may work in concert with chloroplast Hsp70s to regulate nitrate-promoted seed germination. DJC75 is the first pathway component identified for nitrate-promoted seed germination in the dark.

Contrasting seed germination responses to red and far-red light in Leptospermum scoparium and Melicytus ramiflorus

2000 ◽  
Vol 27 (11) ◽  
pp. 1069
Author(s):  
Helen Herron ◽  
John Clemens ◽  
Dennis H. Greer
Keyword(s):  
Seed Germination ◽  
Red Light ◽  
Green Light ◽  
Photon Flux ◽  
Short Term ◽  
Short Term Exposure ◽  
Subsequent Exposure ◽  
R:Fr Ratio ◽  
Leptospermum Scoparium

Effects of red light (R) and far-red light (FR), and selected photon flux densities (PFD) of photosynthetically active radiation (PAR) on seed germination in the photoblastic, primary colonising species Leptospermum scoparium J. R. et G. Forst. and the late secondary successional Melicytus ramiflorus J. R. et G. Forst. were studied. A continuous R dose response curve forL. scoparium germination was developed, unifying data from experiments using long-term exposure to PAR with those following short-term exposure to R. The threshold R dose needed to effect germination was ~0.1 mmol m –2 , and the response was saturated at 1000 mmol m –2 . Stimulation of germination by R was reversed by a subsequent exposure to FR. These features are consistent with a low-fluence response mediated by phytochrome B. FR reversal of germination was achieved at a dose two orders of magnitude lower than that of R required to induce initial germination. However, when both R and FR were provided simultaneously, the FR dose needed to even partially inhibit germination (34% compared to > 95% in controls) was two orders of magnitude higher than the R dose (R:FR ratio = 0.007). Germination in L. scoparium was also stimulated in up to 12% of seed upon diurnal exposure to FR, or by green light (~2 mol m –2 ), indicating a very-low-fluence response mediated by phytochrome A also operating in this species. In contrast, seed germination in M. ramiflorus was relatively unresponsive to R, and secondary dormancy was induced by high PFD (515 mol m –2 s –1 ).

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