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1
Nair, T. S., S. Wilson, and C. Spurr. "Light sensitivity and germination of Eucalyptus globulus seeds." Seed Science and Technology 37, no. 2 (2009): 329–36. http://dx.doi.org/10.15258/sst.2009.37.2.07.
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Albrecht, Matthew A., and Quinn G. Long. "Germination niche of the permanent wetland specialist, Parnassia grandifolia DC." Seed Science Research 24, no. 3 (2014): 239–45. http://dx.doi.org/10.1017/s0960258514000166.
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AbstractTemperate wetland species often require light and warm temperatures for seed germination. However, recent studies indicate that species which specialize on permanently saturated wetlands that are maintained by groundwater discharge (fens, seeps and mountain springs), rather than wetlands with surface-water-driven hydrologic regimes, diverge from the typical wetland germination niche by germinating at cool temperatures and lacking photoblastic seeds. We conducted laboratory experiments that manipulated stratification conditions (non-stratified versus cold stratification in light and darkness), thermal regime (15/6, 25/15 and 35/20°C), and light (14 h photoperiod versus continuous darkness) to test whether seeds of the North American calcareous fen specialist Parnassia grandifolia diverged from the typical temperate wetland germination niche. After 30 d, fresh seeds were conditionally dormant and could only germinate to high percentages in light at 25/15°C. During 16 weeks of incubation, non-stratified seeds germinated to low percentages ( < 40%) at all thermal regimes in darkness. In contrast, cold-stratified seeds germinated to high percentages in both light and darkness at all thermal regimes, although germination was incomplete (no cotyledon emergence) at 35/20°C. Further, seeds did not require light during cold stratification to germinate to high percentages when incubated in light or darkness. Thus, seeds diverged from the typical temperate wetland germination syndrome in lacking a light and warm temperature requirement for germination. Our results reinforce previous work from European fens and Mediterranean wetlands. This indicates that multiple germination strategies are found in fen wetlands that are maintained by the continuous or near-continuous discharge of cool groundwater.
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Doucet, Colleen, and Paul B. Cavers. "Induced dormancy and colour polymorphism in seeds of the bull thistleCirsium vulgare(Savi) Ten." Seed Science Research 7, no. 4 (1997): 399–408. http://dx.doi.org/10.1017/s0960258500003810.
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AbstractTo colonize newly disturbed areas, weedy species must disperse their seeds in space and/or in time.Cirsium vulgarehas poor dispersal in space, but can form a persistent seed bank. Fresh seeds are capable of germinating in either light/dark or constant dark conditions under favourable diurnal temperatures of 25°C: 10°C. Despite this lack of dormancy, a large proportion of seeds do not germinate in the autumn after dispersal. Variation in germination requirements according to seed colour was also examined. Fresh seeds were placed under one of two overwintering treatments at 5°C, alternating light/dark or constant darkness. Some seeds of all colours: white, light, intermediate, dark and black germinated under these conditions. Six months later, ungerminated seeds subjected to the light/dark treatment did not require light for germination when placed under optimal temperatures. However, most seeds that had overwintered in constant darkness required light for germination. In the field, this induced dormancy would prevent seeds from germinating if buried or located in deep shade. Such seeds have the potential of forming a persistent seed bank. The proportion of dormant seeds did not appear to be associated with seed colour. Seeds incubated at 10°C following overwintering under light/dark conditions germinated to a higher percentage than seeds overwintered in darkness, regardless of the light conditions for germination. The results of this study help to explain the contradiction between delayed germination in the field and the lack of seed dormancy.
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Basto, Sofía, and Claudia Ramírez. "Effect of light quality on Tabebuia rosea seed germination." Universitas Scientiarum 20, no. 2 (2014): 191. http://dx.doi.org/10.11144/javeriana.sc20-2.elqt.
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Tabebuia rosea germination capacity and rate have been examined under light and dark conditions. However, seeds responses to light quality, in particular to short and mid-wavelengths, are not well known. We hypothesized that short wavelengths would have a positive effect on rosea germination. The effects of short, mid and long-wavelengths on germination capacity, rate (germination rate index, germination rate R50, a devised index of germination rate R50´ and peak value), mean daily germination and germination value were evaluated. Light quality had little effect on germination capacity; it was reduced only in darkness. Seeds under short and mid-wavelengths germinated faster (germination rate) than under any other light treatments. We concluded that althoughlt T. rosea seeds respond to all light quality treatments, the short and mid-wavelengths are the cue for increasing germination speed. For synchronizing germination, short and mid-wavelengths transmitted by red cellophane paper can be used as a pre-germinative treatment for restoration and silvicultural purposes.
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Feghahati, S. M. Javad, and R. Neil Reese. "Ethylene-, Light-, and Prechill-enhanced Germination of Echinacea angustifolia Seeds." Journal of the American Society for Horticultural Science 119, no. 4 (1994): 853–58. http://dx.doi.org/10.21273/jashs.119.4.853.
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Echinacea angustifolia DC., the common coneflower of the western Great Plains, is difficult to propagate by achenes due to inherent seed dormancy. The effects of light and prechilling on seed germination were examined, alone and combined with scarification (mechanical, acid) and ethylene (ethephon) treatments. The results showed that a 2-week prechill treatment combined with ethephon and continuous light, followed by a 2-week germination period in light (16 hours per day) at 25C, could induce >95% seed germination in E. angustifolia. This was a significantly higher percentage of germination over a shorter period of time than any other method examined or previously described. This treatment also synchronized germination, with most viable seeds germinating in <1 week after being placed at 25C in the light. Chemical name used: 2-chloroethylphosphonic acid (ethephon).
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Roth-Bejerano, Nurit, Norbert J. A. Sedee, Rene M. van der Meulen, and Mei Wang. "The role of abscisic acid in germination of light-sensitive and light-insensitive lettuce seeds." Seed Science Research 9, no. 2 (1999): 129–34. http://dx.doi.org/10.1017/s0960258599000148.
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AbstractThe role of abscisic acid (ABA) in seed germination of two cultivars of lettuce (Lactuca sativa L.; light-sensitive Ritsa and light-insensitive Strada) was investigated. The inhibition of Ritsa seed germination by exogenous ABA was higher than that of Strada seeds, the extent of inhibition of both cultivars being reduced by a short light break. At 25°C the sensitivity of both cultivars to exogenous ABA was higher than at 15°C. The endogenous level of ABA was similar in dry seeds of both cultivars, increasing temporarily in Ritsa seeds during the first 4 h of imbibition in darkness but not in Strada seeds, nor in Ritsa seeds exposed to a short light break. The transitory increase of ABA content in Ritsa seeds imbibed in darkness was accompanied by increased expression of the gene responsive to ABA (Rab) under these conditions. Zorial (Norflurazone), an ABA-biosynthesis inhibitor, decreased ABA content and allowed dark germination of the light-requiring Ritsa seeds. A short light break induced germination of Ritsa seeds when applied at 24 and 48 h after imbibition onset, i.e. after the transitory increase of ABA. GA3, on the other hand was effective when applied at the beginning of imbibition. It seems that light induces germination of the photoblastic Ritsa seeds by both inhibiting ABA synthesis and decreasing seed sensitivity to ABA and inhibitory processes induced by it.
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Herranz, José M., Miguel Á. Copete, Pablo Ferrandis, and Elena Copete. "Intermediate complex morphophysiological dormancy in the endemic Iberian Aconitum napellus subsp. castellanum (Ranunculaceae)." Seed Science Research 20, no. 2 (2010): 109–21. http://dx.doi.org/10.1017/s0960258510000048.
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AbstractSeeds of Aconitum napellus subsp. castellanum were physiologically dormant at maturity in early autumn, with underdeveloped embryos. Thus they have morphophysiological dormancy (MPD). Embryos in fresh seeds were on average 1.01 mm long, and they had to grow to 3.60 mm before radicle emergence. Cold stratification at 5°C for 5 months with light enhanced the mean embryo length to 2.73 mm (SE = 0.13) and seed germination to 20%. However, with higher temperatures (15/4, 20/7, 25/10, 28/14 and 32/18°C) embryo growth was small, with no seeds germinating. Optimal germination was achieved after 4 months of cold stratification at 5°C followed by incubation at 20/7°C for 1 month with light, when germination ranged between 70 and 79%, depending on seed age, locality and year of collection. Cold stratification could be substituted by the application of GA3 solution, since mean embryo length in seeds incubated at 25/10°C for 1 month with light was 3.52 mm and the germination was 80%. Since cold stratification was the only requirement for the loss of MPD, the longest embryo growth occurred during this treatment, and GA3 promoted MPD loss, we concluded that A. napellus seeds have intermediate complex MPD. Germination was higher in 4-month stored than in freshly matured seeds. A pronounced variability in germinative patterns at inter-annual and inter-population level was recorded.
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Genna, Nicholas G., and Héctor E. Pérez. "Mass-based germination dynamics of Rudbeckia mollis (Asteraceae) seeds following thermal and ageing stress." Seed Science Research 26, no. 3 (2016): 231–44. http://dx.doi.org/10.1017/s0960258516000180.
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AbstractSeed mass is an important plant functional trait linked to germination. For instance, higher-mass seeds often display greater germination compared to lower-mass seeds when exposed to non-stressful conditions. Yet, knowledge pertaining to germination dynamics for different mass-based seed fractions following exposure to abiotic stress is lacking. Here, we assess the germination response of relatively fresh, mass-separated Rudbeckia mollis (Asteraceae) seeds to various simulated seasonal temperatures, supra-optimal temperatures and increasing ageing stress duration. Air density separation yielded three mass-based classes, called light (393 ± 35 μg), intermediate (423 ± 29 μg) and heavy (474 ± 38 μg). Water uptake kinetics indicated that imbibition (0–6 h) and germination lag (6–24 h) were independent of seed mass. Similarly, germination and viability loss of fresh seeds following exposure to seasonal and supra-optimal constant temperatures were independent of mass. However, seed mass influenced germination following increasing ageing stress, with light seeds germinating to a significantly greater extent than intermediate or heavy seeds. For example, final germination per cent in light-class seeds was about 1.7 times greater than intermediate or heavy seeds after 20 d of saturated salt accelerated ageing (SSAA). Seeds stored for 1 year in the laboratory displayed mass-dependent germination patterns similar to seeds following SSAA. Mass-independent germination responses may be a strategy to maintain an annual life history in otherwise difficult environments when R. mollis seeds are relatively fresh. However, differences in germination response between aged and unaged seeds suggest that mass-dependent viability loss may occur in R. mollis.
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Marler, Thomas E. "Serianthes nelsonii Seed Germination and Seedling Behavior are Minimally Influenced by Chemical and Light Treatment." Horticulturae 5, no. 2 (2019): 31. http://dx.doi.org/10.3390/horticulturae5020031.
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The role of seed imbibition and light during germination are not known for the critically endangered Serianthes nelsonii Merr. Scarified seeds were pre-soaked in gibberellic acid (GA3) up to 300 mg/L and nitrate solutions of 3000 mg/L to determine if germination was influenced by these treatments. Scarified and imbibed seeds were incubated in high red:far red and low red:far red light to determine the influence of light quality on germination traits. The GA3 and nitrate treatments did not influence germination percentage or timing, but did increase the height of newly emerged seedlings. Moreover, GA3 extended the longevity of cotyledons and shortened the window of time that seedlings required to resume height growth. These growth responses were not sustained, and all seedlings reached heights of 30 cm at a similar number of weeks. The light treatments did not influence any of the germination response traits. The results indicate that imbibing seeds with chemical solutions and providing light in a range of light quality treatments exerted a minimal influence on S. nelsonii seed germination behaviors. Imbibing seeds with water and germinating in darkness is sufficient for achieving the germination of this endangered tree species.
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Baskin, Carol C., Per Milberg, Lars Andersson, and Jerry M. Baskin. "Germination studies of three dwarf shrubs (Vaccinium, Ericaceae) of Northern Hemisphere coniferous forests." Canadian Journal of Botany 78, no. 12 (2000): 1552–60. http://dx.doi.org/10.1139/b00-129.
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Freshly matured seeds of the dwarf shrubs Vaccinium myrtillus L., Vaccinium vitis-idaea L., and Vaccinium uliginosum L. from various sites in coniferous forests in Sweden were tested for germination before and after cold stratification. In initial tests, seeds of V. myrtillus and V. vitis-idaea germinated to 62100% in light at 20:10 and (or) at 25:15°C with few (112%) or no seeds germinating at 15:5(6)°C; however, after 12 or 20 weeks of stratification germination increased significantly in light at 15:5(6)°C. Thus, seeds of these species are conditionally dormant at maturity. Of seeds sown outdoors in southern Sweden on various dates in summer, 120% of V. myrtillus and 02% of V. vitis-idaea germinated before winter. Seeds of neither species germinated during late May, when minimum temperatures were about 710°C, but they did germinate after minimum temperatures increased to [Formula: see text] 10°C. Although stratification increased germination percentages of V. myrtillus and V. vitis-idaea seeds at 15:5(6)°C, more than 2 weeks of incubation at this temperature was required for germination. Thus, even after habitat temperatures have reached the minimum range for germination of nondormant seeds, a slow rate of germination at low temperatures may prevent stratified seeds of both species from germinating in the field in early spring. Nonstratified seeds of V. uliginosum germinated to a maximum of 5% in light and of 7% in darkness, but after 12 weeks of stratification, seeds germinated to 4995% in light and to 160% in darkness at the three temperature regimes. Most seeds of V. uliginosum are dormant at maturity, and they come out of dormancy during stratification in winter. By spring, seeds of V. uliginosum germinate over the same range of temperatures as those of V. myrtillus and V. vitis-idaea, but seeds of V. uliginosum germinate faster at 15:5(6)°C than those of the other two species.Key words: blueberry seed germination, cold stratification, Ericaceae, seed dormancy, seed germination, Vaccinium.
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Willis, AJ, and RH Groves. "Temperature and Light Effects on the Germination of Seven Native Forbs." Australian Journal of Botany 39, no. 3 (1991): 219. http://dx.doi.org/10.1071/bt9910219.
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Seeds of seven native herbaceous species common in natural grasslands and woodlands of south-eastern Australia were tested for germination over a range of alternating temperatures (15/5-35/25°C) with and without light. Seeds were also exposed to low (4°C) and high (50/40°C) temperatures and the addition of gibberellic acid. Tests were conducted on seeds stored for 0-15 months at room temperature. The optimum temperature for germination differed among species, with only Helipterum albicans germinating maximally over all temperatures. Germination of Bulbine bulbosa seed was the most strongly temperature-dependent. Light and cold treatments promoted germination in Helipterum albicans and Vittadinia muelleri only. Short-term dormancy (3-4 months) was shown to occur in fresh seeds of Stylidium graminifolium, Helichrysum apiculatum and Wahlenbergia stricta, but not in seeds of the other species; addition of gibberellic acid to seeds of the two last-named species did not overcome that dormancy. Seeds of all species remained germinable after 15 months of storage. Seeds of most species germinated maximally at 20/10°C. Storage at high alternating temperatures for 1 month inhibited subsequent germination at 30/20° in Leptorhynchos squamatus and S. graminifolium but increased it in V. muelleri, H. albicans and H. apiculatum. In the last species, exposure of 1-month-old seeds to high temperature broke dormancy. These results show that germination and dormancy of seeds of a range of native forbs vary with temperature and light regime; they provide an initial basis on which to test and interpret the effects of seasonal factors on germination and field establishment.
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Flores, Joel, Enrique Jurado, and Alberto Arredondo. "Effect of light on germination of seeds of Cactaceae from the Chihuahuan Desert, Mexico." Seed Science Research 16, no. 2 (2006): 149–55. http://dx.doi.org/10.1079/ssr2006242.
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In the Chihuahuan Desert, there are many cacti species considered to be at risk due to illegal extraction, land-use change and overgrazing. To reduce their illegal extraction,ex situplant propagation has been suggested. However, the literature regarding seed germination biology of these species is scarce. We investigated the effect of light on germination percentages and germination rate (t50) in seeds of 28 cactus species from the Chihuahuan Desert. Seeds were incubated at a 14-h daily photoperiod (light) and in continuous darkness at 25°C for 30 d, after which seeds failing to germinate in darkness were transferred to light for 30 d. Only 11 of the species had non-dormant seeds, germinating ≥70% in the light; thus an evaluation of the effect of light versus darkness on germination was confined to them. All species were positively photoblastic, and all of them had seeds weighing <1 mg. Ten species did not germinate in darkness, and one species had only 7% germination. From these 11 species, 8 did not germinate to a significantly higher percentage when the same set of seeds was transferred from dark to light, suggesting that darkness had triggered secondary dormancy (skotodormancy). To our knowledge, these results are the first to show that darkness triggers secondary dormancy in cacti. Implications of having a light requirement for germination and having small seeds to accumulate a persistent soil seed bank are discussed. These results contribute to understanding the germination biology of cactus species at risk, and could enhance the propagation of large numbers of cultivated individuals outside their habitats, promotingex situconservation.
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Jain, Rakesh, and Megh Singh. "Factors Affecting Goatweed (Scoparia dulcis) Seed Germination." Weed Science 37, no. 6 (1989): 766–70. http://dx.doi.org/10.1017/s0043174500072817.
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Goatweed seeds require light for germination, with optimum germination occurring at 25/20 or 30/25 C day/night temperatures. Germination was 8.5% 7 days after incubation at 20/15 C. At 15/10 C, no germination occurred, irrespective of the light treatment. Chilling at 4 C for 10 days prior to incubation at 30/25 C did not induce germination of dark-incubated seeds and had no effect on germination of light-incubated seeds. A photoperiod of at least 1 h daily was required to induce germination. Maximum germination, however, occurred with a 9-h photoperiod. Light intensity as low as 25 μE·m–2·s–1induced germination of goatweed seeds. Germination percentage increased with an increase in light intensity. Treatment with 1 mM gibberellic acid or 10 or 100 mM sodium nitrate or ammonium nitrate solution was effective in enhancing germination of light-incubated seeds, but not in inducing germination of dark-incubated seeds. Ammonium nitrate at 10 and 100 mM was more effective than sodium nitrate at the same concentrations in enhancing germination of goatweed seeds in the light. Ammonium chloride did not increase percent germination over that of seeds incubated in distilled water in the light. Germination percentage was maximum at pH 10 and at osmotic potentials 0.0 MPa.
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Altom, John V., and Don S. Murray. "Factors Affecting Eclipta (Eclipta prostrata) Seed Germination." Weed Technology 10, no. 4 (1996): 727–31. http://dx.doi.org/10.1017/s0890037x00040720.
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Controlled environmental chamber experiments were conducted for a 14-d incubation period to measure the effect of temperature, light, light intensity, water potential, and pH on eclipta seed germination. In full light, seed germinated over a range of 10 to 35 C; however, germination was highest at 83% at 35 C. Seeds were strongly photoblastic with none germinating in the dark. Seeds germinated in light intensities between 6 and 100% of full light. Seeds germinated 78 to 88% in water potentials of 0.0, −0.1, and −0.2 MPa. In distilled water (pH ∼ 5.5) and a buffered solution pH 6 and 7, seeds germinated 85 to 89%; however, some seeds germinated in a buffered solution pH range of 5 to 8. After the first 14-d incubation period, ungerminated seeds were transferred to distilled water and incubated at 35 C in full light for 4 to 6 d as a second incubation period. Seeds germinated 89 to 96% after this second incubation period when first incubation was at temperatures 10 to 35 C in full light or darkness, light intensities 0 to 100% of full light, water potentials 0.0 to −0.8 MPa, and buffered solution pH levels of 5.5 to 7.
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Gonçalves, Maura Lúcia Costa, and Massanori Takaki. "The role of the seed coat in the light sensivity in Raphanus sativus L. cv. redondo gigante seeds." Acta Botanica Brasilica 11, no. 1 (1997): 55–60. http://dx.doi.org/10.1590/s0102-33061997000100006.
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The role of the seed coat in the light sensitivity of seeds of Raphanus sativus L. cv. redondo gigante was analysed by germination tests of intact and naked seeds. Far-red light caused high inhibition of seed germination, while under white and red lights low inhibition was found. Naked seeds presented no light sensitivity with high percentage germination under light and darkness. However, incubation of naked seeds in -0.6MPa polyethylene glycol solution resulted in light inhibition as observed in intact seeds. The analysis of the seed coat transmitted light indicated that the filtered light presented the same photoequilibrium of phytochrome when compared to the white light, with a decrease of only 33% in the light irradiance which reaches the embryo.
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Brechu-Franco, Alicia, Felipe Cruz-Garcia, Judith Marquez-Guzman, and Guillermo Laguna-Hernandez. "Germination ofSicyos deppei(Cucurbitaceae) Seeds as Affected by Scarification and Light." Weed Science 40, no. 1 (1992): 54–56. http://dx.doi.org/10.1017/s0043174500056940.
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Sicyos deppeiG. Don (Cucurbitaceae) is an annual weed that disperses dormant seeds. The influence of scarification and light on their germination was studied in the laboratory. Scarified seeds collected in 1987, 6, 7, 8, and 9 mo postharvest, gave high germination both in white light (89 to 100%) and darkness (64 to 96%), in comparison with nonscarified seeds which germinated 7 to 20% in both conditions. Scarified seeds collected in 1989, 3 mo postharvest, germinated higher (52 to 69%) than nonscarified seeds (0 to 5%). Exposure to light did not break dormancy of nonscarified seeds. The reversal of dormancy by scarification describes them as hard seeds. Scarified seeds, 3 mo postharvest, were light indifferent, germinating even in the usually inhibitory condition of far-red light. However, a low proportion of scarified seeds, 6 and 7 mo postharvest, presented a positive photoblastic response and germinated 23 and 36%, respectively.
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Bourgoin, A., and J. D. Simpson. "Soaking, moist-chilling, and temperature effects on germination of Acer pensylvanicum seeds." Canadian Journal of Forest Research 34, no. 10 (2004): 2181–85. http://dx.doi.org/10.1139/x04-092.
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The effect on germination of soaking duration, moist-chilling time, and temperature was evaluated using five seed lots of Acer pensylvanicum L. Seeds were soaked for 0, 48, 72, or 96 h, then moist chilled at 4 °C for 16, 24, or 32 weeks. Two temperature regimes were used for germination: (i) 16 h dark at 5 °C : 8 h light at 15 °C (5:15 °C) and (ii) 16 h dark at 20 °C : 8 h light at 30 °C (20:30 °C). Soaking and chilling seeds significantly increased germination. Germination was highest at 5:15 °C, but the germination speed was slow. Germination at 20:30 °C was lower, but 94%98% of ungerminated seeds appeared to be viable, suggesting that they were dormant. Overall results showed that soaking seeds for 48 h, moist chilling for 16 weeks, and germinating at 5:15 °C produced an average germination of 92%.
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Thanos, C. A., and K. Mitrakos. "Watermelon seed germination. 2. Osmomanipulation of photosensitivity." Seed Science Research 2, no. 3 (1992): 163–68. http://dx.doi.org/10.1017/s096025850000129x.
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AbstractSeed germination of watermelon (Citrullus lanatus cv. Sugar Baby) was fully suppressed by intermittent far-red (FR) irradiation (1 min every 30 min). When the intervening dark period was increased, a linearly increasing final germination percentage was obtained. However, a 4-day intermittent FR treatment induced phytochrome-controlled dormancy and the longer the dark interval the deeper was the dormancy of the non-germinated seeds. When seeds were soaked in a fully inhibitory osmotic solution, no dormancy was imposed. However, a single FR pulse at the time of transfer induced partial, secondary dormancy; the kinetics of the imposition of dormancy followed a negative exponential curve (half-life 1.5 days; 3 days for the cultivar Crimson Sweet). Seeds osmotreated for 10 days in darkness and subsequently dehydrated (with and without a final FR pulse) acquired germination characteristics similar to those in light-requiring and dark-germinating achenes, respectively, of the lettuce cultivar Grand Rapids. In the light-requiring osmomanipulated seed population, the induction of germination was brought about by the low-energy reaction of phytochrome, chilling, dry storage and decoating. The transformation through osmomanipulation of the dark-germinating watermelon seeds (the inhibition of which required prolonged exposure to light) to positively or negatively photosensitive seeds (that responded to brief light pulses), might be attributed to the slow relaxation of existing meta-Fa and meta-Rb phytochrome intermediates to Pfr upon hydration.
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Hermesh, R., and S. N. Acharya. "Influence of maternal plant environment and provenance on alpine bluegrass seed germination." Canadian Journal of Plant Science 72, no. 3 (1992): 801–8. http://dx.doi.org/10.4141/cjps92-096.
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Adequate restoration of alpine disturbances requires seed material capable of germinating in high proportions and at a rapid rate. Germination of alpine bluegrass (Poa alpina L.) seeds of different provenances and produced under different environmental conditions was compared under uniform conditions of 16/8 h cycles of light/dark and 22/15 °C temperature. Seeds from nursery plots at the Alberta Environmental Centre, Vegreville, germinated in significantly higher proportions and faster than seeds from the same accessions grown in alpine environments. Alpine bluegrass clones grown in controlled environment chambers set at 22/15 °C and 15/8 °C light/dark with a 16-h photoperiod produced seeds with higher rates of germination and greater cumulative germination than seeds produced in an 8/1 °C regime. It is suggested that alpine blue-grass seeds with high germination percentage and rates are best produced under prairie nursery conditions.Key words: Alpine bluegrass, Poa alpina L., seed germination, maternal environment
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Baird, James H., and Ray Dickens. "Germination and Emergence of Virginia Buttonweed (Diodia virginiana)." Weed Science 39, no. 1 (1991): 37–41. http://dx.doi.org/10.1017/s0043174500057830.
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Virginia buttonweed seeds germinated at temperatures between 15 and 40 C, with optimal germination occurring at 25 or 30 C in 12 h light alternated with 15 to 25 or 20 to 30 C in darkness, respectively. Germination rate was lower in continuous darkness than in light. Germination was reduced under simulated water stress conditions with less than 10% of seeds germinating at osmotic potentials below −0.3 MPa. Overall seed germination was reduced under simulated flooding conditions; greater germination occurred in aerated water than in unaerated water. Maximum germination occurred at pH 6. Seedlings emerged from depths as great as 8 cm, with maximum emergence occurring from 2 cm.
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Schwintzer, Christa R., and Andrea Ostrofsky. "Factors affecting germination of Myricagale seeds." Canadian Journal of Forest Research 19, no. 9 (1989): 1105–9. http://dx.doi.org/10.1139/x89-167.
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Several factors affecting seed germination were investigated in Myricagale L., a nitrogen fixing shrub common on wet soils. Light was essential: seeds failed to germinate in the dark and required four 16-h photoperiods (one per day) for maximum germination. There was no absolute requirement for prechilling, but prechilling increased germination by 75% in 2-month-old seeds and by 164% in 4.5 year-old seeds. Leaching did not affect germination and 500 ppm gibberellic acid enhanced germination only 20%. The seeds were long-lived: there was no decrease in percent germination during 6 years of dry storage at 5 °C and germination remained high after 1 year of wet storage at 5 °C. Because M. gale seeds often germinate on water-worked substrates, the requirement for extended exposure to light for germination may serve as a mechanism to prevent unsuccessful germination of seeds that are reburied after brief exposure to light as sediments are worked by water.
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Pandey, D. K., and L. M. S. Palni. "Germination of Parthenium hysterophorus L. seeds under the influence of light and germination promoting chemicals." Seed Science and Technology 33, no. 2 (2005): 485–91. http://dx.doi.org/10.15258/sst.2005.33.2.21.
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Grzybowski, Camila Ribeiro de Souza, Rosemeire Carvalho da Silva, Elisa Serra Negra Vieira, and Maristela Panobianco. "Maturation and germination of Vernonanthura discolor seeds." Ciência e Agrotecnologia 40, no. 2 (2016): 164–72. http://dx.doi.org/10.1590/1413-7054201640202215.
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ABSTRACT Vernonanthura discolor is a native species with potential for reclamation of degraded lands, and the manufacture of wood panels. This study has aimed to evaluate the process of maturation and germination of Vernonanthura discolor seeds, determining the harvest time, and conducting the germination test. A periodic monitoring of the reproductive development of sources of Vernonanthura discolor was conducted, located in the municipality of Bocaiúva do Sul, PR, Brazil; and starting from the anthesis, weekly collections of seeds were performed to evaluate the percentage of dry matter, germinating power, and vigor, in order to identify the physiological maturity of the seeds. In the germination test, two combinations of four temperatures (20, 30, 20-30 and 30 °C), and two light regimes were tested, seeking to define the best methodology and evaluation dates of the test. It was concluded that the seeds physiological maturity Vernonanthura discolor reached 45 days after the anthesis, when the maximum values of dry weight, germination and vigor are achieved. Germination test may be conducted on blotting paper at 20 or 25 °C with a supply of light, or at 25 °C in the dark, the first count being on the 13th and the last one on the 29th day after seeding.
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Eremrena, P. O., and S. I. Mensah. "Effect of plant growth regulators and nitrogenous compounds on seed germination of pepper (Capsicum frutescens L)." Journal of Applied Sciences and Environmental Management 20, no. 2 (2016): 242–50. http://dx.doi.org/10.4314/jasem.v20i2.3.
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The seed germination of Capsicum frutescens L. was investigated through various methods, namely, washing and air dry storage treatments, applications of gibberelic acid (GA3), Kinetin, potassium nitrite (KNO2) and potassium nitrate (KNO3) to improve germination of seeds in view of poor germination reported. The seeds were subjected to the following treatments namely washing to remove the slimy coverings; air-drying at various time-intervals; incubated in different concentrations of GA3, Kinetin, KNO2 and KNO3. The treatments were subjected to light or dark germinations at 300C and radicle emergence scored after 15days. The various results showed that washing treatment, and light germination had a significant effect on the germination of Capsicum frutescens seeds. For air-drying treatment, germination increased from 0-48hrs and decreased after 72hrs, 48hrs air-drying duration gave the highest percentage germination. Application of GA3, kinetin, KNO2 and KNO3 in low concentrations promoted the germination of freshly harvested Capsicum frutescens seeds. Generally the KNO2 and KNO3 gave the best germination results. The findings of this study have significant implications in the commercial production of Capsicum frutescens in view of its economic and medicinal importance.Keywords: Growth regulators, Nitrogenous compounds, Capsicum frutescens
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Jha, Prashant, Jason K. Norsworthy, Melissa B. Riley, and William Bridges. "Annual Changes in Temperature and Light Requirements for Germination of Palmer Amaranth (Amaranthus palmeri) Seeds Retrieved from Soil." Weed Science 58, no. 4 (2010): 426–32. http://dx.doi.org/10.1614/ws-d-09-00038.1.
Full textAbstract:
Experiments were conducted on Palmer amaranth seeds collected in 2004 and 2006 from a natural population near Pendleton, SC, to determine the temperature and light requirements for germination of seeds retrieved from soil surface or from 10-cm depth in the field. A cyclic change in seed germination of Palmer amaranth in response to temperature and light occurred during a 12-mo after-ripening period. Freshly matured seeds collected in November required mean temperatures ≥ 25 C, and natural or red (R) light for increased germination. Following after-ripening in winter, seeds experienced a reduction in dormancy and germinated higher at 25 to 35 C mean compared with 10 to 15 C mean. With after-ripening for an additional 3 mo in May, seeds experienced a broadening of thermal range (10 to 40 C mean), and germination in natural light or R light was more than twice the germination in the absence of light. Fluctuating temperatures (7.5 C amplitude) improved germination over constant temperatures, except in summer and fall (9 and 12 mo after seed maturation). Exposure of seeds to high temperatures during summer caused secondary dormancy induction. Averaged over thermal amplitudes, seeds retrieved in fall required mean temperatures > 25 C for increased germination. Burial in spring for 3 to 6 mo induced seed dormancy, and the relative germination in fall (12 mo after seed maturation) was at least 50% higher for seeds retrieved from soil surface compared to seeds exhumed from 10-cm soil depth. Seeds retrieved in late summer and fall required natural light or R light for promoting germination, whereas far-red (FR) light or darkness inhibited germination. Furthermore, the effect of R and FR light was reversible, indicating a partially phytochrome-mediated germination response of Palmer amaranth seeds following 9 to 12 mo of after-ripening in the field.
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Susko, David J., and Yara Hussein. "Factors Affecting Germination and Emergence of Dame's Rocket (Hesperis matronalis)." Weed Science 56, no. 3 (2008): 389–93. http://dx.doi.org/10.1614/ws-07-156.1.
Full textAbstract:
Laboratory experiments were conducted to determine the effects of temperature, light, cold stratification, dry storage, solution pH, solution osmotic potential, and planting depth on germination and emergence of dame's rocket. Maximal germination (> 80%) of fresh seeds occurred at alternating temperatures ≥ 25/15 C in both alternating light/dark and continuous darkness. However, < 10% of seeds germinated at or below 20/10 C, with lower germination in the presence of light than in darkness. Cold stratification at 4 C for 4 to 16 wk enhanced germination at low alternating temperatures (≤ 20/10 C), but depressed germination at warm temperature regimes (≥ 25/15 C). After 1 yr of dry storage (after-ripening), germination exceeded 94% and did not differ significantly among temperature regimes. Germination exceeded 60% in solutions with pH 3 to 10. Germination was reduced below 50% in solutions with osmotic potentials below −0.6 MPa. Percent emergence was greater than 56% at burial depths in soil of 0 to 5 cm, with maximal emergence (93 to 99%) at 0 to 2 cm. Dame's rocket seeds possess non-deep physiological dormancy at maturity, but when dormancy is alleviated, the seeds are capable of germinating in a variety of climatic and edaphic conditions.
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NOLAN, DARYL G., and MAHESH K. UPADHYAYA. "PRIMARY SEED DORMANCY IN DIFFUSE AND SPOTTED KNAPWEED." Canadian Journal of Plant Science 68, no. 3 (1988): 775–83. http://dx.doi.org/10.4141/cjps88-090.
Full textAbstract:
Large numbers of viable, diffuse (Centaurea diffusa Lam.) and spotted knapweed (C. maculosa Lam.) seeds (achenes), collected in the interior of British Columbia, failed to germinate in darkness at 25 °C. This primary dormancy was released to varying degrees by gibberellic acid, exposure to red light, or excision of the distal end of the seed. The effect of red light was negated by subsequent exposure to far-red light. The demonstration of red/far-red reversibility implicates the phytochrome pigment system in the light-sensitive germination of knapweed seeds. Seeds collected from different sites, and from individual plants within sites, had different germination levels in darkness and following exposure to 2 min of red light. Three types of germination behavior were evident: nondormant seeds germinated in darkness; light-sensitive dormant seeds germinated in response to red light; and light-insensitive dormant seeds failed to germinate after 5 d of continuous red light. Seeds of all three germination types were found on individual plants.Key words: Centaurea diffusa, Centaurea maculosa, knapweed, seed dormancy, light-sensitive germination, germination polymorphism
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Souza, Alexandre Fadigas De, Antonio Carlos Silva De Andrade, Flavio Nunes Ramos, and Marta Bruno Loureiro. "Ecophysiology and morphology of seed germination of the neotropical lowland tree Genipa americana (Rubiaceae)." Journal of Tropical Ecology 15, no. 5 (1999): 667–80. http://dx.doi.org/10.1017/s026646749900108x.
Full textAbstract:
The morphology of Genipa americana seeds and post-seminal development was studied, and its germination response investigated in relation to storage in water, substrate water volume, osmotic potential and temperature and light regimes. The seeds are flattened and seedlings are phaneroepigeal with leafy cotyledons. Seeds stored in water kept viable for up to 6 mo, but germination and seedling emergence were reduced after 4 mo. Germination was not affected under water-logged conditions, but seedling emergence was reduced at the water volume corresponding to a water column two times deeper than the seeds' mean thickness (70 ml). When seeds were osmotically stressed, a reduction in the rate and germination percentage occurred at −0.2 MPa and germination was drastically inhibited at −0.6 MPa. Seeds germinated in a wide range of temperatures (15–40 °C), with optimum at continuous temperatures of 25 and 30 °C. Light was not required for germination, and no dormancy mechanisms were observed. The seed and seedling morphology and the germinative responses of the species may permit its regeneration in periodically flooded lowland forests and riparian habitats and are probably key factors in explaining the species' wide distribution.
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Veronika, Valičková, Hamouzová Kateřina, Kolářová Michaela, and Soukup Josef. "Germination responses to water potential in Bromus sterilis L. under different temperatures and light regimes." Plant, Soil and Environment 63, No. 8 (2017): 368–74. http://dx.doi.org/10.17221/406/2017-pse.
Full textAbstract:
Barren brome (Bromus sterilis L.) is a troublesome weed of winter cereals in western and central Europe and its control requires an exact estimation of emergence time. The study focused on the germination response of populations from the Czech Republic to water availability at different temperatures and under different light regimes. Seeds were able to germinate even at very low water potential (Ψ) close to the wilting point, but decreasing temperatures below 25°C and exposure to light decreased the germination percentage (GP) and prolonged the time to reach 50% germination (T<sub>50</sub>). At higher temperatures of 15, 20, and 25°C, seeds germinated up to a Ψ value of–1.5 MPa; however, the GP differed between light (0–3%) and darkness (50–75%). At the highest temperature of 25°C and germination in water, T<sub>50</sub> was less than 1 day, but a decrease in Ψ to –1.5 MPa prolonged the T<sub>50</sub> to<br /> 5 days; however, this occurred without any significant effect of light regime. With decreasing temperature and Ψ, seeds were more sensitive to the light regime and the disproportion between T<sub>50</sub> in light and darkness increased. At a Ψ of less than –1.0 MPa, seeds needed twice as long for germination in light than in darkness when germinating at 20°C or 15°C. The results may be of value for the development of predictive models and for identifying times when weed control may be the most effective.
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Wang, Hong-Ling, Chang-Yan Tian, and Lei Wang. "Germination of dimorphic seeds of Suaeda aralocaspica in response to light and salinity conditions during and after cold stratification." PeerJ 5 (August 15, 2017): e3671. http://dx.doi.org/10.7717/peerj.3671.
Full textAbstract:
Cold stratification is a requirement for seed dormancy breaking in many species, and thus it is one of the important factors for the regulation of timing of germination. However, few studies have examined the influence of various environmental conditions during cold stratification on subsequent germination, and no study has compared such effects on the performance of dormant versus non-dormant seeds. Seeds of halophytes in the cold desert might experience different light and salinity conditions during and after cold stratification. As such, dimorphic seeds (non-dormant brown seeds and black seeds with non-deep physiological dormancy) of Suaeda aralocaspica were cold stratified under different light (12 h light–12 h darkness photoperiod or continuous darkness) or salinity (0, 200 or 1,000 mmol L-1 NaCl) conditions for 20 or 40 days. Then stratified seeds were incubated under different light or salinity conditions at daily (12/12 h) temperature regime of 10:25 °C for 20 days. For brown seeds, cold stratification was also part of the germination period. In contrast, almost no black seeds germinated during cold stratification. The longer the cold stratification, the better the subsequent germination of black seeds, regardless of light or salinity conditions. Light did not influence germination of brown seeds. Germination of cold-stratified black seeds was inhibited by darkness, especially when they were stratified in darkness. With an increase in salinity at the stage of cold stratification or germination, germination percentages of both seed morphs decreased. Combinational pre-treatments of cold stratification and salinity did not increase salt tolerance of dimorphic seeds in germination phase. Thus, light and salinity conditions during cold stratification partly interact with these conditions during germination stage and differentially affect germination of dimorphic seeds of S. aralocaspica.
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Paudel, Niroj, and Prakash Deep Rai. "Germination responses of seeds of Desmodium triflorum." International Journal of Scientific Reports 4, no. 2 (2018): 19. http://dx.doi.org/10.18203/issn.2454-2156.intjscirep20180392.
Full textAbstract:
<p class="abstract"><strong>Background:</strong> Germination of <em>Desmodium triflorum</em> is used for the scarification using the acid is valuable for the different light condition.</p><p class="abstract"><strong>Methods:</strong> The sample was collected as four month of interval of time and the seed is treated with acids with different time. </p><p class="abstract"><strong>Results:</strong> seeds scarified with sulfuric acids for 10 min before sowing had better germination than those scarified for 5 and 15 min. Among them light qualities, red and white light had slightly promoted effect whereas blue light and dark condition had slightly negative effect on seed germination.</p><p><strong>Conclusions:</strong> In comparison to blue light and dark condition, red light and white light were promoted to percentage germination indicating the role of phytochrome in seed germination of <em>Desmodium triflorum</em>. </p>
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El-Keblawy, Ali A., Arvind Bhatt, and Sanjay Gairola. "Perianth colour affects germination behaviour in wind-pollinated Salsola rubescens in Arabian deserts." Botany 92, no. 1 (2014): 69–75. http://dx.doi.org/10.1139/cjb-2013-0183.
Full textAbstract:
Salsola rubescens Franch. is a wind-pollinated halophytic shrub that produces fruits with red and yellow winged perianths. Germinability of seeds from both fruit types was determined under various light, temperature, and salinity treatments. Red seeds, with and without winged perianths, were heavier than yellow seeds. Germination percentage and germination rate index (speed) were significantly affected by the perianth colour, presence of wings, and temperature and light of incubation and most of their interactions. Germination percentage was greater for yellow-winged seeds than for red-winged seeds. Wing removal significantly enhanced the germination percentage and germination speed in the two types. The presence of wings enhanced germination at lower temperatures, but wing absence enhanced germination at higher temperatures. Wing removal enhanced germination to a greater degree in yellow than in red seeds. There was no light requirement during germination of red-winged seeds, but yellow-winged seeds germinated significantly more in light than in darkness. Red-winged and dewinged seeds were more tolerant to salinity than yellow seeds. Removal of wings significantly increased salinity tolerance for seeds of both wing colours. It is concluded that the showy perianth colours have an ecological role in wind-pollinated plants in regulating dormancy and germination behaviour in the heterogeneous unpredictable hyperarid deserts.
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Victório, Cristiane Pimentel, Nina Cláudia Barbosa da Silva, Maria Apparecida Esquibel, and Alice Sato. "The influence of light spectra, UV-A, and growth regulators on the in vitro seed germination of Senecio cineraria DC." Revista Ceres 57, no. 5 (2010): 576–80. http://dx.doi.org/10.1590/s0034-737x2010000500002.
Full textAbstract:
This study was carried out to investigate the effects of light spectra, additional UV-A, and different growth regulators on the in vitro germination of Senecio cineraria DC. Seeds were surface-sterilized and inoculated in MS medium to evaluate the following light spectra: white, white plus UV-A, blue, green, red or darkness. The maximum germinability was obtained using MS0 medium under white light (30%) and MS + 0.3 mg L-1 GA3 in the absence of light (30.5%). S. cineraria seeds were indifferent to light. Blue and green lights inhibited germination. Different concentrations of gibberellic acid (GA3) (0.1; 0.4; 0.6; 0.8; 1.0 and 2.0 mg L-1) and indole-3-acetic acid IAA (0.1; 0.3 and 1.0 mg L-1) were evaluated under white light and darkness. No concentration of GA3 enhanced seed germination percentage under white light. However, when the seeds were maintained in darkness, GA3 improved germination responses in all tested concentrations, except at 1.0 mg L-1. Under white light, these concentrations also increased the germination time and reduced germination rate. Germination rate, under light or darkness, was lower using IAA compared with GA3.
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Kozarewa, Iwanka, Daniel J. Cantliffe, Russell T. Nagata, and Peter J. Stoffella. "High Maturation Temperature of Lettuce Seeds during Development Increased Ethylene Production and Germination at Elevated Temperatures." Journal of the American Society for Horticultural Science 131, no. 4 (2006): 564–70. http://dx.doi.org/10.21273/jashs.131.4.564.
Full textAbstract:
Ethylene synthesis and sensitivity, and their relation to germination at supraoptimal temperatures, were investigated in lettuce (Lactuca sativa L.) seeds matured at 30/20 °C [12-h day/night, high temperature matured (HTM)] or 20/10 °C [12-h day/night, low temperature matured (LTM)]. HTM seeds of both thermosensitive `Dark Green Boston' (DGB) and thermotolerant `Everglades' (EVE) had greater germination at a supraoptimal temperature (36 °C), in both light or dark, than LTM seeds of DGB and EVE. HTM seeds of DGB and EVE produced more ethylene during germination than LTM seeds, regardless of imbibition conditions. The ethylene action inhibitor, silver thiosulfate, led to reduced germination in both cultivars. The ethylene precursor, 1-aminocyclopropane-1-carboxylic acid at 10 mm increased germination of both cultivars at supraoptimal temperatures, whereas germination of HTM seeds was greater than that of LTM seeds. No differences in ethylene perception were detected between HTM and LTM germinating seeds using a triple response bioassay. This study demonstrated that at least one method through which seed maturation temperature influences lettuce germination is by affecting ethylene production.
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Pinto Paim, Luciana, Eduarda Demari Avrella, Juliana Carolina Alves Horlle, Claudimar Sidnei Fior, Marília Lazarotto, and André Pich Brunes. "Response of Lupinus bracteolaris seeds to pre-germinative treatments and experimental conditions." Revista de Investigación Agraria y Ambiental 12, no. 2 (2021): 51–66. http://dx.doi.org/10.22490/21456453.4278.
Full textAbstract:
Contextualization: Lupinus bracteolaris is a heliophite species that vegetates low lands, open slopes and sandstone hills.
 Knowledge gap: Despite the high rusticity and potential for covering poor soils, there is still no information to assist in the analysis of its seeds.
 Purpose: To determine pre-germinative treatments, substrate, temperature, luminosity and water intake in the vigor of Lupinus bracteolaris seeds.
 Methodology: Fruits were collected from 20 matrix plants, then the seeds were processed and submitted to the following tests: pre-germinative methods (six treatments at 25°C); substrates and temperatures (sand and paper at 20, 25 and 30°C); photoblast test (white light, diffuse-green light and continuous dark under 20°C) and the imbibition curve (control and scarification between sandpaper under 20°C). Evaluations: percentage of germination and formed seedlings, germination speed index, average germination time and seedling formation, using a completely randomized design.
 Results and conclusions: According to the analyzed variables, the results showed superiority for the pre-germinative treatment between sandpapers for 20 seconds. In addition, the substrate paper germibox and the temperature of 20°C were the most suitable during seed germination. The seeds of Lupinus bracteolaris were classified as neutral-photoblastic and without dormancy.
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Procházka, Petr, and Jiří Dvořák. "Spread, dormancy and germination of seeds of field pansy." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 54, no. 2 (2006): 81–90. http://dx.doi.org/10.11118/actaun200654020081.
Full textAbstract:
Viola arvensis Murray is in Czech Republic the important field weed. They were observed production and germinating of seeds in various conditions (influence on light, temperature, time of bedding after ripening), spread of seeds, germination and evolution of plant. It was prove positive influence darkness in germination of seeds and influence of low temperature on interfere with dormancy. After reach of results are production of seeds, their properties, spread on the area and rapidity of the evolution of plants there is assumption of the hight dynamism of this species.
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Bai, Yuguang, James T. Romo, and James A. Young. "Influences of Temperature, Light and Water Stress on Germination of Fringed Sage (Artemisia frigida)." Weed Science 43, no. 2 (1995): 219–25. http://dx.doi.org/10.1017/s0043174500081108.
Full textAbstract:
Experiments were conducted to determine the influences of temperature, light, winter storage, and water stress on seed germination of fringed sage. Seeds collected in 3 yr in central Saskatchewan were placed in sealed vials and buried in the soil after harvest, and germination was tested in spring and early summer. Seeds germinated over a wide range of temperatures with alternating 25/15 C being optimal. The range of optimal temperatures was higher for older seeds than younger seeds. The stimulating effect of light on germination varied among collections and incubating temperatures. Total germination and germination rate was limited by water stress and no seeds germinated at osmotic potentials below −0.9 MPa. Seeds hydrated in the autumn and exposed to low winter temperatures had higher germination the following spring than dry seeds exposed to the same conditions. Results suggest that sufficient soil moisture combined with moderate seedbed temperatures are optimal for fringed sage germination. Periodicity of germination may be influenced by variable germination requirements in different aging seeds.
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Stawska, Marlena, and Krystyna Oracz. "phyB and HY5 are Involved in the Blue Light-Mediated Alleviation of Dormancy of Arabidopsis Seeds Possibly via the Modulation of Expression of Genes Related to Light, GA, and ABA." International Journal of Molecular Sciences 20, no. 23 (2019): 5882. http://dx.doi.org/10.3390/ijms20235882.
Full textAbstract:
Light is one of the most important environmental factors regulating seed germination. It is known that light inhibits seed germination of some monocotyledonous species and that it is mostly related to the blue wavelength of the spectrum received by cryptochromes (cry). Research has also found that the red light (R) stimulates germination of dicotyledonous seeds and that this reaction involves mainly phytochromes (phy). Surprisingly, up to date, the role and the mechanism of action of blue light (BL) in seed biology of dicot plants is still very poorly understood and some questions are unexplained, e.g., whether BL plays a role in regulation of dicot seeds dormancy and/or germination? If, so what particular elements of light signaling pathway are involved in modulation of this(ese) process(es)? Also, is the BL action in regulation of dicot seeds dormancy and/or germination maybe due to changes of expression of genes related to metabolism and/or signaling of two phytohormones controlling seed-related events, such as gibberellins (GA) and abscisic acid (ABA)? To answer these intriguing questions, the combination of biological, transcriptomic, and genetic approaches was performed in this particular study. The germination tests show that freshly harvested wild type (WT) Arabidopsis thaliana Col-0 seeds are dormant and do not germinate in darkness (at 25 °C), while nondormant (after-ripened) seeds germinate well in these conditions. It is also proven that dormancy of seeds of this species is released in the presence of white and/or BL (λ = 447 nm) when placed at 25 °C. Presented here, novel results emphasize the role of BL in dormancy alleviation of dicot seeds, indicating that this wavelength of light spectrum received by phyB induces this process and that the sensitivity to this stimulus depends on the depth of seed dormancy. In addition, it is demonstrated that various elements of phy-mediated pathway can be used in response to the signal induced by BL in germinating dormant seeds of Arabidopsis. The quantitative real time PCR analysis supported by results of germination tests of WT, T-DNA insertion mutants (i.e., hy5, hfr1, and laf1) and overexpression transformants of Arabidopsis seeds (i.e., 35S:OE:HY5, 35S:OE:HYH, 35S:OE:HFR1, and 35S:OE:LAF1) revealed that the HY5 gene coding transcription factor is most probably responsible for the control of expression of genes involved in GA/ABA metabolism and/or signaling pathways during BL-dependent dormancy alleviation of Arabidopsis seeds, while biological functions of HYH and HFR1 are associated with regulation of germination. The model of BL action in regulation of dormancy alleviation and germination potential of Arabidopsis seeds is proposed.
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Brasileiro, Beatriz Gonçalves, Denise Cunha F. S. Dias, Vicente Wagner Dias Casali, Maria Carmen Bhering, and Paulo Roberto Cecon. "Effects of temperature and pre-germinative treatments on seed germination of Talinum triangulare (Jacq. ) willd (Portulacaceae)." Revista Brasileira de Sementes 32, no. 4 (2010): 151–57. http://dx.doi.org/10.1590/s0101-31222010000400017.
Full textAbstract:
The objective of this study was to evaluate the effects of temperature, substrate and pre-germinative treatments on T. triangulare seeds. Four temperatures (constant 20, 25, 30 °C and alternate 20-30 °C) and two types of seeding (on paper and between paper), with light, were evaluated. The pre-germinative treatments evaluated included: immersion in water (24 hours), immersion in 6% hypochlorite solution (1 hour), immersion in 0.2% potassium nitrate solution (24 hours), immersion in 0.05% gibberellin solution (24 hours) and the control (untreated seeds). The highest germination percentage was observed at the alternate temperatures of 20-30 ºC, but with no significant difference between the substrates at this temperature. Soaking seeds in KNO3 gave the highest percentage germination and germination speed index (GSI), which differed from the other treatments except for soaking in water. Pre-soaking of T. triangulare seeds favors germination and may be done only in pure water, resulting in a more rapid and uniform germination.
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Li, X. J., P. J. Burton, and C. L. Leadem. "Interactive effects of light and stratification on the germination of some British Columbia conifers." Canadian Journal of Botany 72, no. 11 (1994): 1635–46. http://dx.doi.org/10.1139/b94-201.
Full textAbstract:
Pregermination stratification treatment was generally more important than the effects of light on seed germination by 14 conifer species and varieties native to British Columbia. Nevertheless, there were some strong species differences in the response of germination to light. Final germination percentage after 21 days (28 days for Abies spp.) for both stratified and unstratified seeds of Picea glauca, Picea sitchensis, and Tsuga heterophylla showed no response to light during germination. Seed germination by Abies grandis, Pinus contorta var. contorta, Pinus contorta var. latifolia, Pinus ponderosa, Pseudotsuga menziesii var. glauca, and Pseudotsuga menziesii var. menziesii responded positively to light if unstratified but was not significantly affected by light when stratified. For Thuja plicata seeds, germination responded positively to light regardless of stratification pretreatment. Light appeared to reduce germination of stratified seeds of Abies amabilis, Abies lasiocarpa, Larix occidentalis, and Pinus monticola, although stratification conditions for these species were suboptimal. The germination rate of stratified seeds of all species and unstratified seeds of most species was increased by light. Results showed no significant relationship between germination response to light and shade-tolerance ranking or mean seed weight of the species. In six seed lots of Pinus contorta var. latifolia, however, we detected a weak negative correlation between mean seed weight and unstratified light responsivity measured after 1 week but a significant positive correlation when measured after 3 weeks. Very low light levels in closed-canopy forests or in the forest floor may prolong tree seed germination but are unlikely to constrain final germination levels after most seeds have been naturally stratified by moist, cool winter conditions. The importance of differences in the rate and timing of tree seed germination under natural conditions remains to be demonstrated. Key words: conifer biology, forest regeneration, light response, lodgepole pine, Pinus contorta, seed germination, stratification.
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Gansberger, Markus, Hans-Peter Stüger, Manfred Weinhappel, et al. "Germination characteristic of Silphium perfoliatum L. seeds." Die Bodenkultur: Journal of Land Management, Food and Environment 68, no. 2 (2017): 73–79. http://dx.doi.org/10.1515/boku-2017-0007.
Full textAbstract:
SummarySilphium perfoliatumL. is a perennial and flowering crop that has been investigated in recent years for its potential as an energy plant, particularly for biogas production. A stand establishment by sowing of seeds is complicated, owing to the low germination capacity of untreatedS.perfoliatumL. seeds. Consequently, germination experiments were carried out with two- to four-factor levels to determine the effect of selected factors (medium, pretreatment, light, temperature, prechilling) on dormancy and germination ofS.perfoliatumL. seeds and to achieve maximum germination rate. All factors had a highly significant effect on germination. Germination experiments displayed a primary and physiological dormancy. Germination could be significantly increased by using a 0.05% GA3solution during the imbibition phase, a light–dark cycle, alternating temperatures between 20°C and 30°C, and a wet stratification for seven days at 0°C. The experiments helped to fully exploit the germination potential and to develop a germination test method forS.perfoliatumL.
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Freitas, Nobel Penteado, and Massanori Takaki. "Pelletization of seeds of Raphanus sativus L. cv. Redondo Gigante with graphite for germination under water stress conditions." Brazilian Archives of Biology and Technology 43, no. 5 (2000): 547–50. http://dx.doi.org/10.1590/s1516-89132000000500016.
Full textAbstract:
The effect of water stress on germination of radish seeds is dependent on the presence of light. The effect of pelletization of radish seeds with powdered graphite on the tolerance to water stress under light was analysed. White light and far-red lights were filtered by graphite increasing slightly the tolerance of pelleted seeds to water stress of -0.77MPa. Although red light also inhibited seed germination the graphite had no effect. We propose the pelletization of seeds of Raphanus sativus, at least in cv redondo gigante with graphite as a pratice before planting to increase the tolerance to water stress.
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Socolowski, Fábio, Daniela Cristine Mascia Vieira, Edson Simão, and Massanori Takaki. "Influence of light and temperature on seed germination of Cereus pernambucensis Lemaire (Cactaceae)." Biota Neotropica 10, no. 2 (2010): 53–56. http://dx.doi.org/10.1590/s1676-06032010000200005.
Full textAbstract:
The objective of the present study was to evaluate the effects of light and temperature on germination of Cereus pernambucensis seeds, a species of columnar cactus native to Brazil and naturally incident in the restinga. Cereus pernambucensis seeds were incubated under different temperatures, from 5 to 45 °C, with 5 °C intervals, and under alternating temperatures of 15-20 °C, 15-30 °C, 20-25 °C, 20-30 °C, 20-35 °C, 25-30 °C, 25-35 °C, and 30-35 °C, both under continuous white light and dark. The seeds were also incubated in a gradient of phytochrome photoequilibrium at 25 °C. The highest percentage germination in this species was between 25 and 30 °C. The minimum temperature was between 15 and 20 °C and the maximum between 35 and 40 °C. Alternating temperatures did not affect the percentage of seed germination, but it did alter the rate and synchronization indexes. Seeds incubated in the dark did not germinate under any of the conditions tested, indicating that this species when cultivated present light sensitive seeds controlled by phytochrome. The seeds can tolerate a lot of shade conditions, germinating under very low fluence response of phytochrome.
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Ramos, Flavio Nunes, and Antonio Carlos Silva de Andrade. "Seed germination of a rare neotropical canopy tree dormancy and the effects of abiotic factors." Revista Árvore 34, no. 3 (2010): 443–49. http://dx.doi.org/10.1590/s0100-67622010000300008.
Full textAbstract:
The purpose of this study was to examine if germination is a critical phase on Enterolobium glaziovii regeneration. Hence, the germinative response of E. glaziovii seeds was investigated in relation to some of the main environmental factors (temperature, light and water stress) to which its seeds are subjected in the forest, as well as its dormancy and the longevity of its burial seeds. According to our results, its seeds may be regarded as photoblastic neutral. They do not need alternating temperatures to germinate and can germinate under a broad range of water stress. However, only about 10% of E. glaziovii seeds remain viable after one year. In other words, the annual fruiting, instead seed longevity, seems to maintain the long-term seed availability of this species. Consequently, the seed longevity could be a critical phase of E. glaziovii germination.
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Thapliyal, Ramesh C., Shyam S. Phartyal, Jerry M. Baskin, and Carol C. Baskin. "Role of mucilage in germination of Dillenia indica (Dilleniaceae) seeds." Australian Journal of Botany 56, no. 7 (2008): 583. http://dx.doi.org/10.1071/bt08022.
Full textAbstract:
Dillenia indica Linn. is a nearly evergreen tree widely distributed in South-east Asia. Regeneration is by seeds borne within large indehiscent fruits. When extracted fresh, seeds are glued together by the sticky mucilage on the seedcoat. Mucilage anchors seeds during rains, thus preventing them from escaping the fruit. Mucilage does not promote or inhibit germination, but it does restrict the inflow of water into seeds during the initial stages of imbibition. In nature, seeds germinate (within fruits) in July–August following heavy rains that wash off most of the mucilage. Light had a significant effect on germination: a 12/12 h light/dark regime resulted in more and faster germination than when seeds were incubated in total darkness. Seeds exhibited one flush of germination within fruits and another flush in the laboratory following extraction, drying and rehydration, suggesting the occurrence of two physiological types of seeds with regard to light requirement for germination. The embryo of D. indica is underdeveloped, and seeds take ~30 days to germinate under appropriate conditions. Thus, the seeds have morphological dormancy (MD). The possible roles of seed-coat mucilage and light in the germination biology of D. indica seeds in nature are discussed.
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ESASHI, YOHJI, HIROSHI OOTA, HISATO SAITOH, and HIROAKI KODAMA. "Light Actions in the Germination of Cocklebur Seeds." Journal of Experimental Botany 36, no. 9 (1985): 1465–77. http://dx.doi.org/10.1093/jxb/36.9.1465.
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ESASHI, YOHJI, NORITOSHI FUWA, KAZUKO KOJIMA, and SHUU HASE. "Light Actions in the Germination of Cocklebur Seeds." Journal of Experimental Botany 37, no. 11 (1986): 1652–62. http://dx.doi.org/10.1093/jxb/37.11.1652.
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ESASHI, YOHJI, SHUU HASE, and KAZUKO KOJIMA. "Light Actions in the Germination of Cocklebur Seeds." Journal of Experimental Botany 38, no. 4 (1987): 702–10. http://dx.doi.org/10.1093/jxb/38.4.702.
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Nascimento, Warley Marcos. "Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature." Scientia Agricola 60, no. 3 (2003): 477–80. http://dx.doi.org/10.1590/s0103-90162003000300010.
Full textAbstract:
Lettuce (Lactuca sativa L.) seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB) were incubated at temperatures ranging from 15° to 35°C at light and dark conditions. Other seeds were imbibed in dark at 20°; 25°; 30°; and 35°C for 8 and 16 hours and then transferred to 20 or 35°C, in dark. Seeds were also incubated at constant temperature of 20° and 35 °C, in the dark, as control. In another treatment, seeds were primed for 3 days at 15°C with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25°C. Seeds incubated at 20°C had 97% germination, whereas seeds incubated at 35°C did not germinate. Seeds imbibed at 20°C for 8 and 16 hours had germination. At 35°C, seeds imbibed initially at 20°C for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25°C for 16 hours, germinated satisfactory at 35°C. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20°C. Primed seeds had 100% germination at 35°C, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.
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Mihălescu, Lucia, Zorica Voşgan, Oana Mare Roşca, et al. "Study of the Influence of External Factors on the Germination of Bean Seeds." Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture 73, no. 2 (2016): 345. http://dx.doi.org/10.15835/buasvmcn-agr:12423.
Full textAbstract:
The aim of our study was to follow the influence of the substrate, (single respectively double filter paper), the environment conditions (light, darkness), of the seed’s measure and age, on the beans germination. These aspects were followed because the specialty literature correlates the loss of the germinative capacity with different external and internal factors. Three local varieties: P1 (Albenghino), P2 (Cannellini), P3 (Black Turtle), grown in Maramures County, with undetermined growth and different permeability of the seminal skin, were chosen for the experiment. One hundred seeds of every sort were placed in three replications. The energy and germinative faculty were determined, calculating the average values obtained at the replications. We noted that the P2 variety had the highest germinative faculty of 83.33% on double layer under light conditions, and the germination of 100% under darkness. The P1 variety is on the second place. The germinative faculty of the P3 variety is of only 70% on a single substrate and 80% on double layer. The germinative energy and faculty of the seeds provided from 2013 are diminished comparatively with those from 2014. The local population P3 proved to be more influenced by age, with a germinative energy of 30% in 2013 and 60% in 2014. The positive influence of the darkness conditions, both for the seeds provided from 2013 and 2014, was noted.