Ecophysiology of seed germination in Mediterranean geophytes. 1. Muscari spp

Ecophysiological aspects of seed germination were investigated in four Mediterranean geophytes of the genus Muscari (Liliaceae): M. comosum (tassel hyacinth), M. neglectum (common grape hyacinth), M. commutatum and M. weissii. Experiments were performed at constant temperatures in the dark and under temperature and light conditions simulating those prevailing in nature during November–January, i.e. well into the rainy season of the Mediterranean climate. In all species, no primary dormancy was revealed, and germination occurred in a rather narrow range of cool temperatures (optimum at 10 or 15°C) and at a remarkably slow rate; both germination characteristics seem to be associated with autumn/winter seed germination and seedling establishment. Such a postulated strategy is ecologically advantageous within an unpredictable rainfall regime, known to prevail during the start of the rainy period of the Mediterranean climate. This strategy may also explain the spread of germination of M. comosum seeds over two consecutive years, observed by Theophrastus. Far-red light, simulating light conditions under a dense canopy, resulted in only a slight delay of germination compared to dark controls. Diurnal white light, qualitatively simulating natural daylight, caused a significant decrease of the germination rate in all four species studied. Moreover, white light was found to suppress considerably final seed germination (photoinhibition) in M. weissii and M. neglectum; in the latter species, prolonged imbibition under white light also led to the induction of secondary dormancy.

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Germination and seed conservation of a pioneer species, Tecoma stans (Bignoniaceae), from tropical dry forest of Colombia

Revista de Biología Tropical ◽

10.15517/rbt.v66i2.33423 ◽

2018 ◽

Vol 66 (2) ◽

pp. 918

Author(s):

Jhon Alexander Vargas-Figueroa ◽

Alba Marina Torres-González

Keyword(s):

Seed Germination ◽

White Light ◽

Germination Rate ◽

Red Light ◽

Tropical Dry Forest ◽

Seed Storage ◽

Dry Forest ◽

Storage Behavior ◽

Mean Germination Time ◽

Seed Storage Behavior

Seed germination and seed longevity under different environmental conditions are fundamental to understand the ecological dynamics of a species, since they are decisive for its success within the ecosystem. Taking this into account, seed germination and seed storage behavior of a pioneer species of tropical dry forest (Tecoma stans) were studied in the laboratory, to establish the effect of different environmental conditions on a local tree population. Two seed lots collected in July 2011, from Cali (Colombia), were evaluated under three alternating temperatures (20/30, 20/25, 25/30 ºC; 16/8 h) and four light qualities (12-hour white light photoperiod, darkness, and 15 minutes of red light -R and far red light -FR). Final germination was recorded for all treatments; for white light treatment the daily germination was recorded to calculate mean germination rate, mean germination time, and two synchronization indices. To assess the effect of light quality on physiological variables, a destructive germination test was carried out. For this test, another seed lot was evaluated under the same light conditions using an alternating temperature of 20/30 °C - 16/8 h, recording germination during six days for every treatment. In addition, seeds were stored at two different moisture contents (7.7, 4.1 %) and three storage temperatures (20, 5, -20 ºC), during two time periods (one and three months); a seed germination test was conducted for each treatment. Four replicates of 35 seeds per treatment were used for all experiments. Germination was high (GP > 90 %) with all alternating temperatures under white light, whereas under R, FR, and darkness germination was evenly successful at low temperatures, but at higher temperature, half of the seeds entered into secondary dormancy (GP= 45-65 %). However, mean germination rate and synchronization under R and FR decreased significantly in comparison to white light treatment and, consequently, mean germination time increased. Seed storage behavior of this species is orthodox due to the high germination (GP > 90 %) obtained under all treatments. In conclusion, T. stans seeds have a negative germination response at high incubation temperatures in the absence of white light, entering into a secondary dormancy. In contrast, an environment with a lower temperature and without white light delays the germination, but at the end seeds are able to reach the same germination values. This seed dependence on incident light in limiting conditions suggests a physiological mechanism on the seed tissues of this species, probably mediated by phytochromes. Finally, the orthodox seed storage behavior of T. stans is a reason to include this species in ex situ seed conservation programs for restoration and recovery of the tropical dry forest; however, long-term studies should be conducted in order to evaluate the maintenance of this characteristic throughout longer periods of time. Rev. Biol. Trop. 66(2): 918-936. Epub 2018 June 01.

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Seed Germination of Some Flower Species Under Influence of Different Light Conditions

Агрознање ◽

10.7251/agren1602183t ◽

2017 ◽

Vol 17 (2) ◽

pp. 183

Author(s):

Monika Tkalec ◽

Тijana Mirković ◽

Mario Mitrović ◽

Nada Parađiković ◽

Jasna Kraljičak ◽

...

Keyword(s):

Seed Germination ◽

Blue Light ◽

White Light ◽

Germination Rate ◽

Dianthus Caryophyllus ◽

Light Conditions ◽

Germination Energy ◽

Significant Difference ◽

Set Up ◽

Local Store

The aim of this study was to examine germination energy and seed germination rate of some flower species under influence of different light conditions. Seeds of Zinnia elegans Jacq., Dianthus caryophyllus L. and Callistephus chinensis (L.) Nees that were used in the research were purchased in local store. Experiment was set up in three replicates for each light treatment and each flower species. Petri dishes with seeds were placed in growth chamber under artificial white and blue light under 12hL/12hD photoperiod. Results showed no significant difference in germination energy and total germination of investigated flower species in respect of light. Zinnia seedlings were significantly longer on white light, while Dianthus seedlings were longer on blue light. Both, length and fresh weight of Callistephus seedlings were greater on white light. The absence of significant differences between measured parameters under examined light regimes suggests that germination of Zinnia, Dianthus and Callistephus is not photosensitive.

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Ecophysiology of germination in the aromatic plants thyme, savory and oregano (Labiatae)

Seed Science Research ◽

10.1017/s0960258500002786 ◽

1995 ◽

Vol 5 (3) ◽

pp. 161-170 ◽

Cited By ~ 67

Author(s):

Costas A. Thanos ◽

Costas C. Kadis ◽

Flora Skarou

Keyword(s):

Seed Germination ◽

Essential Oils ◽

Mediterranean Climate ◽

Red Light ◽

Adaptation Strategy ◽

Rain Gauge ◽

Aromatic Plants ◽

Origanum Vulgare ◽

Rainy Period ◽

Satureja Thymbra

AbstractEcophysiological aspects of seed germination were investigated in the widely distributed Mediterranean-endemic, aromatic plants thyme (Coridothymus capitatus), savory (Satureja thymbra) and oregano (Origanum vulgaresubsp.hirtum). Thyme seed germination is light indifferent, whereas oregano seeds have an absolute light requirement; their germination can be promoted even by green safelight or far-red light. In savory, a portion of the seeds germinates in the dark and germination can be either increased or decreased by the appropriate illumination. All three species show more germination at a relatively low temperature range, a Mediterranean characteristic, with an optimum around 15–20°C. The rate of germination is considerably higher in the tiny seeds of thyme and oregano than in the larger seeds of savory. In the latter species, germination is also dependent upon the age of the seeds; old seeds germinate to a higher percentage than fresh ones, as already observed by Theophrastus, possibly as a result of the volatilization of the essential oils present on the nutlet coat. Seeds of thyme, savory and oregano are dispersed within the persistent fruiting calyces and the seeds eventually germinate within it. Essential oils in the calyx strongly inhibit germination of the enclosed seeds; germination is much suppressed in thyme and to a lesser extent in savory and oregano. This diaspore dormancy caused by essential oils apparently is overcome under natural conditions by leaching of the inhibitors with rainwater. It is suggested that this dormancy operates as an adaptation strategy that delays germination by acting as a rain gauge. In this way, seed germination and subsequent seedling establishment are prevented during the early phase of the rainy period, which is usually interrupted by drought spells in the Mediterranean climate.

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

Annals of Botany ◽

10.1093/aob/mcaa040 ◽

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.

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Far-Red Light Acclimation for Improved Mass Cultivation of Cyanobacteria

Metabolites ◽

10.3390/metabo9080170 ◽

2019 ◽

Vol 9 (8) ◽

pp. 170 ◽

Cited By ~ 3

Author(s):

Alla Silkina ◽

Bethan Kultschar ◽

Carole A. Llewellyn

Keyword(s):

Biomass Production ◽

White Light ◽

Light Emitting Diode ◽

Red Light ◽

Industrial Biotechnology ◽

Light Conditions ◽

Light Emitting ◽

Mass Cultivation ◽

Chlorogloeopsis Fritschii ◽

Bioactive Product

Improving mass cultivation of cyanobacteria is a goal for industrial biotechnology. In this study, the mass cultivation of the thermophilic cyanobacterium Chlorogloeopsis fritschii was assessed for biomass production under light-emitting diode white light (LEDWL), far-red light (FRL), and combined white light and far-red light (WLFRL) adaptation. The induction of chl f was confirmed at 24 h after the transfer of culture from LEDWL to FRL. Using combined light (WLFRL), chl f, a, and d, maintained the same level of concentration in comparison to FRL conditions. However, phycocyanin and xanthophylls (echinone, caloxanthin, myxoxanthin, nostoxanthin) concentration increased 2.7–4.7 times compared to LEDWL conditions. The productivity of culture was double under WLFRL compared with LEDWL conditions. No significant changes in lipid, protein, and carbohydrate concentrations were found in the two different light conditions. The results are important for informing on optimum biomass cultivation of this species for biomass production and bioactive product development.

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The influence of light spectra, UV-A, and growth regulators on the in vitro seed germination of Senecio cineraria DC.

Revista CERES ◽

10.1590/s0034-737x2010000500002 ◽

2010 ◽

Vol 57 (5) ◽

pp. 576-580 ◽

Cited By ~ 1

Author(s):

Cristiane Pimentel Victório ◽

Nina Cláudia Barbosa da Silva ◽

Maria Apparecida Esquibel ◽

Alice Sato

Keyword(s):

Seed Germination ◽

Growth Regulators ◽

White Light ◽

Germination Rate ◽

Germination Percentage ◽

Ms Medium ◽

In Vitro Germination ◽

Light Spectra ◽

Indole 3 Acetic Acid

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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Quantitative trait loci associated with lettuce seed germination under different temperature and light environments

Genome ◽

10.1139/g08-077 ◽

2008 ◽

Vol 51 (11) ◽

pp. 928-947 ◽

Cited By ~ 27

Author(s):

Eiji Hayashi ◽

Natsuyo Aoyama ◽

David W. Still

Keyword(s):

Quantitative Trait Loci ◽

Seed Germination ◽

Path Analysis ◽

Quantitative Trait ◽

Germination Rate ◽

Red Light ◽

Seed Maturation ◽

Lettuce Seed ◽

Factors Affecting ◽

Trait Loci

Temperature and light are primary environmental cues affecting seed germination. To elucidate the genetic architecture underlying lettuce ( Lactuca sativa L.) seed germination under different environmental conditions, an F8 recombinant inbred line population consisting of 131 families was phenotyped for final germination and germination rate. Seeds were imbibed in water at 20 °C under continuous red light (20-Rc), 20 °C continuous dark (20-Dc), 31.5 °C continuous red light (31.5-Rc), 31.5 °C continuous dark (31.5-Dc), or 20 °C far-red light for 24 h followed by continuous dark (20-FRc-Dc). Thirty-eight quantitative trait loci (QTL) were identified from two seed maturation environments: 10 for final germination and 28 for germination rate. The amount of variation attributed to an individual QTL ranged from 9.3% to 17.2% and from 5.6% to 26.2% for final germination and germination rate, respectively. Path analysis indicated that factors affecting germination under 31.5-Rc or 31.5-Dc are largely the same, and these appear to differ from those employed under 20-FRc-Dc. QTL and path analysis support the notion of common and unique factors for germination under diverse temperature and light regimes. A highly significant effect of the seed maturation environment on subsequent germination capacity under environmental stress was observed.

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The Effects of Light Color on Seed Germination of Markhamia stipulata (Wall.) Seem

KnE Life Sciences ◽

10.18502/kls.v3i4.710 ◽

2017 ◽

Vol 3 (4) ◽

pp. 233

Author(s):

Sri Ulie Rahmawati ◽

Arief Noor Rachmadiyanto

Keyword(s):

Seed Germination ◽

Germination Rate ◽

Block Design ◽

Red Light ◽

Botanical Garden ◽

Dark Light ◽

Significant Difference ◽

Length Width ◽

Light Color ◽

And Control

Markhamia stipulata (Wall.) Seem. (Bignoniaceae) is one of collections in Bogor Botanical Garden that potential as a medicine. Information about germination of these species were not known yet. This research was aimed to examine the effect of light color on germination process of Markhamia stipulata (Wall.) Seem. The research method used a Randomized Complete Block Design (RCBD) that consist of three treatments (red light, far red light, dark) and one control (open air) with four replications for each group. Each group consist of 10 seeds. Precentage of seed germination; seedling height; cotyledon width; length, width and number of leaves were measured. The result showed that seed germination start at third day after sowing. Germination rate and germination rate coefficcient showed there is no significant difference between all treatments even though far red light showed highest number (100 %; 0.755). However, light color influence on seedling growth. Far red light showed affect on internodes distance. Dark light showed affect on leaves and cotyledon size. Red light and control showed similarity. <div>Keywords: dark; far red light, Markhamia stipulata (Wall.) Seem; red light; seed germination</div>

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Germination responses of seeds of Desmodium triflorum

International Journal of Scientific Reports ◽

10.18203/issn.2454-2156.intjscirep20180392 ◽

2018 ◽

Vol 4 (2) ◽

pp. 19 ◽

Cited By ~ 1

Author(s):

Niroj Paudel ◽

Prakash Deep Rai

Keyword(s):

Seed Germination ◽

Blue Light ◽

White Light ◽

Red Light ◽

Light Condition ◽

Dark Condition ◽

Percentage Germination ◽

Negative Effect

Background: Germination of Desmodium triflorum is used for the scarification using the acid is valuable for the different light condition.Methods: The sample was collected as four month of interval of time and the seed is treated with acids with different time. Results: 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.Conclusions: 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 Desmodium triflorum.

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The Alleviation Effect of Silicon on Seed Germination and Seedling Growth of Tomato Under Salinity Stress

Vegetable Crops Research Bulletin ◽

10.2478/v10032-012-0008-z ◽

2012 ◽

Vol 76 (1) ◽

pp. 119-126 ◽

Cited By ~ 8

Author(s):

Maryam Haghighi ◽

Zahra Afifipour ◽

Maryam Mozafarian

Keyword(s):

Seed Germination ◽

Salinity Stress ◽

Seedling Growth ◽

Germination Rate ◽

Germination Percentage ◽

Percentage Germination ◽

Tomato Seeds ◽

Germination Characteristics ◽

Salinity Levels ◽

Mean Germination Time

The Alleviation Effect of Silicon on Seed Germination and Seedling Growth of Tomato Under Salinity StressThis study was conducted to evaluate the effectiveness of silicon (Si) application under salinity levels on seed germination and growth characteristics of tomato seeds. A laboratory experiment was performed on completely randomized design with two levels of salinity (25 and 50 mM NaCl) and 2 concentration of Si (1 and 2 mM) with 4 replications. Germination percentage, germination rate, seedling shoot and root length, fresh and dry weight of seedling and mean germination time was measured. Seed germination ofLycopersicon esculentumL. was significantly affected by salinity levels, Si and their interaction. Germination characteristics of tomato seeds decreased drastically by increasing NaCl concentrations. However, 1 mM Si had positive effects on seed germination characteristics and improved germination percentage, germination rate and mean germination time. Si alleviated the harmful effect of salinity stress on tomato seed germination at almost all germination characteristics.

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