Physical dormancy in seeds of Dodonaea viscosa (Sapindales, Sapindaceae) from Hawaii

2004 ◽  
Vol 14 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Jerry M. Baskin ◽  
Barbara H. Davis ◽  
Carol C. Baskin ◽  
Sean M. Gleason ◽  
Susan Cordell
Keyword(s):  
Seed Coat ◽  
White Light ◽  
Red Light ◽  
Dodonaea Viscosa ◽  
Physical Dormancy ◽  
Critical Moisture Content ◽  
Temperature Regimes ◽  
Wide Range ◽  
Critical Moisture ◽  
Impermeable Seed Coat

Dormancy in seeds ofDodonaea viscosais due to a water-impermeable seed coat (physical dormancy, PY). Thus, mechanically scarified seeds imbibed water (c.95% increase in mass) and germinated to high percentages over a wide range of temperature regimes in both white light and darkness, whereas non-scarified seeds did not take up water. Dry heat at 80–160°C and dipping in boiling water for 1–60 s also broke dormancy in a high percentage of the seeds, and continuous far-red light was not inhibitory to germination. However, dry storage in the laboratory for >1 year did not overcome dormancy. Seeds made water-permeable by boiling imbibed water, and thus germinated, at a much slower rate than those made water-permeable by mechanical scarification. We suggest that boiling opened the ‘water gap’ in the seed coat (not yet described inSapindaceaebut present in other taxa with PY) and that water entered the seed only through this small opening, thereby accounting for the slow rate of imbibition and subsequent germination. Physical dormancy has now been shown to occur in seeds of this polymorphic, worldwide species from Australia, Brazil, Hawaii, Mexico and New Zealand. The low level of dormancy reported for seed lots ofD. viscosain China, India and Pakistan is probably due to collection of seeds before they dried to the critical moisture content for development of water-impermeability of the seed coat. Germination of non-dormant seeds over a wide range of temperatures and in white light, far-red (leaf-canopy shade) light and darkness are part of the germination strategy ofD. viscosaand of other taxa whose seeds have PY at maturity.

Physical dormancy in seeds of Dodonaea viscosa (Sapindaceae) from India

2005 ◽  
Vol 15 (1) ◽  
pp. 59-61 ◽  
Author(s):  
S.S. Phartyal ◽  
J.M. Baskin ◽  
C.C. Baskin ◽  
R.C. Thapliyal
Keyword(s):  
Seed Dormancy ◽  
Seed Coat ◽  
Geographical Range ◽  
Western India ◽  
Dodonaea Viscosa ◽  
Physical Dormancy ◽  
Impermeable Seed Coat ◽  
North Western

In contrast to reports in the literature that seeds of Dodonaea viscosa from China and Pakistan are non-dormant, or nearly so, we found that a high percentage of seeds of this species collected in north-western India have a water-impermeable seed coat at maturity, i.e. physical dormancy. Thus, seeds that were mechanically scarified and boiled (to open a ‘water gap’ in the seed coat) germinated to much higher percentages (84% and 77%, respectively) than did those that were non-scarified (24%). Our results agree with studies of seed dormancy in this species in various other parts of its large geographical range.

scholarly journals Efectividad de algunos tratamientos pre-germinativos para ocho especies leñosas de la Mixteca Alta oaxaqueña con características relevantes para la restauración

2017 ◽  
pp. 9
Author(s):  
Gilberto Martínez-Pérez ◽  
Alma Orozco-Segovia ◽  
Carlos Martorell
Keyword(s):  
Seed Coat ◽  
Native Species ◽  
Immature Embryo ◽  
New Method ◽  
Dodonaea Viscosa ◽  
Physical Dormancy ◽  
Mixteca Alta ◽  
Physiological Dormancy ◽  
Wearing Off ◽  
Do So

When restoring highly degraded areas such as the Mixteca Alta (Oaxaca State, Mexico), it is important to use native species that promote natural succession. To do so, we need to know whether their seeds have dormancy and how to break it. We compared different pre-germination treatments of eight species relevant for restoration. The results were analyzed with a new method that solves some of the statistical problems that arise when examining these experiments. In Acacia schaffneri, Ipomoea murucoides, Mimosa aculeaticarpa and Dodonaea viscosa wearing off the seed coat by means of abrasion or heating promotes rapid germination, proving the presence of physical dormancy. Despite belonging to families that show physiological dormancy only, the seeds of Arctostaphylos pungens and Juniperus flaccida germinate after immersion in acid. This procedure may have weakened the seed coat, allowing the immature embryo to break it. We found weak physiological dormancy in Quercus deserticola, and no apparent dormancy in Quercus castanea.

A new seed coat water-impermeability mechanism in Chaetostoma armatum (Melastomataceae): evolutionary and biogeographical implications of physiophysical dormancy

2015 ◽  
Vol 25 (2) ◽  
pp. 194-202 ◽  
Author(s):  
Rafaella C. Ribeiro ◽  
Denise M.T. Oliveira ◽  
Fernando A.O. Silveira
Keyword(s):  
Phenolic Compounds ◽  
Seed Coat ◽  
Seed Weight ◽  
Significant Fraction ◽  
Distilled Water ◽  
Physical Dormancy ◽  
First Report ◽  
Germination Ecology ◽  
Impermeable Seed Coat ◽  
Structure Water

AbstractDetermining the phylogenetic and biogeographic distribution of physical dormancy remains a major challenge in germination ecology. Here, our goal was to describe a novel water-impermeable seed coat mechanism causing physical dormancy (PY) in the seeds of Chaetostoma armatum (Melastomataceae). Although seed coat permeability tests indicated a significant increase in seed weight after soaking in distilled water, anatomical and dye-tracking analyses showed that both water and dyes penetrated the seed coat but not the embryo, which remained in a dry state. The water and dye penetrated the lumen of the exotestal cells, which have a thin outer periclinal face and thickened secondary walls with U-shaped phenolic compounds. Because of this structure, water and dye do not penetrate the inner periclinal face of the exotestal cells, indicating PY. Puncturing the seeds increased germination more than tenfold compared to that of the control, but GA3 did not increase germination further. A significant fraction of the seeds did not germinate after puncturing, indicating that embryos are also physiologically dormant (PD). This paper constitutes the first report of the water-impermeable seed coat in the Myrtales and the first report of physiophysical (PD+PY) dormancy in a shrub from a tropical montane area.

scholarly journals Germinación de Chiranthodendron pentadactylon Larr. (Sterculiaceae), en respuesta a la escarificación, temperatura y luz

2017 ◽  
pp. 5
Author(s):  
Reyna Osuna-Fernández ◽  
Guillermo Laguna-Hernández ◽  
Alicia Brechú-Franco ◽  
Alma Orozco-Segovia
Keyword(s):  
Seed Germination ◽  
Seed Coat ◽  
White Light ◽  
Maternal Effect ◽  
Seed Quality ◽  
Variable Temperature ◽  
Red Light ◽  
Seed Viability ◽  
Weather Conditions ◽  
Two Populations

Seed quality and seed germination with scarification and non scarification and variable temperature and light were determined in Ch. pentadactylon seeds form two places of Guerrero and Oaxaca. Also seed viability was determined in seeds from Guerrero stored 6 months at 5º C. Seeds showed to be orthodox and dormant due to an impervious seed coat. The seeds from Guerrero had higher weight, length and water content than those from Oaxaca, however the scarified seeds from Oaxaca reached a higher germination percentages. Germination of scarified seeds of the two populations was enhanced by alternated temperatures and inhibited by far red light. Germination under darkness, red light and white light did not differ significantly. In soil some seeds could be dormant under a low ratio red:far red light transmitted by litter. The differences between the two populations might be due to a maternal effect induced by weather conditions in their geographic localities.

Combinational dormancy in seeds of the Western Australian endemic species Diplopeltis huegelii (Sapindaceae)

2006 ◽  
Vol 54 (6) ◽  
pp. 565 ◽  
Author(s):  
S. R. Turner ◽  
D. J. Merritt ◽  
J. M. Baskin ◽  
C. C. Baskin ◽  
K. W. Dixon
Keyword(s):  
Seed Coat ◽  
Endemic Species ◽  
Hot Water ◽  
Constant Darkness ◽  
Physical Dormancy ◽  
Australian Species ◽  
Dry Storage ◽  
Seed Characteristics ◽  
Impermeable Seed Coat ◽  
Western Australian

Seeds of the endemic Western Australian species Diplopeltis huegelii Endl. were successfully germinated after the presence of combinational dormancy was identified, following the observation of selected seed characteristics. D. huegelii seeds were found to have large, fully developed, peripheral coiled embryos (with no endosperm) that are 7–8 mm long when uncoiled. Seed-coat dormancy was overcome by dipping seeds in hot water for ≥15 s, but seeds also required a period of after-ripening before they would germinate readily. After-ripening occurred while intact seeds were stored dry at ambient laboratory conditions for 13 months or when scarified (hot-water treated) seeds were stored at 13, 23 or 50% RH at 23°C for 6 weeks. Scarified 13-month-old seeds germinated readily at 7/18, 13/26 and 18/33°C in a 12-h photoperiod and in constant darkness, whereas scarified 1-month-old seeds germinated to ≤43%. Thus, seed dormancy in this species is caused by a water-impermeable seed coat (physical dormancy, PY) and a (non-deep) physiologically dormant embryo (PD), i.e. combinational dormancy (PY + PD). This is only the second report of combinational dormancy in seeds of Sapindaceae and the first report in this family of the PD component of (PY + PD) being broken during dry storage.

A STUDY OF GERMINATION IN THE SEED OF WILD RICE (ZIZANIA AQUATICA)

1966 ◽  
Vol 44 (1) ◽  
pp. 1-9 ◽  
Author(s):  
G. M. Simpson
Keyword(s):  
Gibberellic Acid ◽  
Seed Coat ◽  
Wild Rice ◽  
Complete Loss ◽  
Low Oxygen ◽  
Air Drying ◽  
Zizania Aquatica ◽  
Wide Range ◽  
Oxygen Tensions ◽  
Impermeable Seed Coat

Dormancy lasted about 6 months in seeds of Zizania aquatica afterripened at 1–3 °C. Embryos lost dormancy fastest when afterripened under low oxygen tensions. Pricking the water-impermeable seed coat removed some dormancy. Low constant temperatures favored maximum rates of germination, as did alternating high and low, but constant high temperatures decreased rates. Changes in pH between 6.0 and 8.7, and a wide range of concentrations of gibberellic acid had no significant effects on germination. Air-drying of seeds for 90 days caused almost complete loss of viability; a detectable decrease occurred within 14 days. Under certain conditions, freezing caryopses also caused loss of viability. These results are discussed in relation to the habitat of wild rice.

Growth Response and Carbohydrate Status of Gibberellin-treated Spectral Filter-grown Chrysanthemum Plants

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522c-522
Author(s):  
Anuradha Tatineni ◽  
Sonja L. Maki ◽  
Nihal C. Rajapakse
Keyword(s):  
Plant Height ◽  
Growth Regulation ◽  
Red Light ◽  
Sucrose Phosphate Synthase ◽  
Spectral Filter ◽  
Spectral Filters ◽  
Wide Range ◽  
Ornamental Crops ◽  
Carbohydrate Levels ◽  
Carbohydrate Status

Interest in the use of non- (or less) chemical methods to reduce the height of ornamental crops has increased tremendously. Manipulation of greenhouse light quality is one alternative for plant growth regulation. We have shown that eliminating far-red light from the greenhouse environment with liquid CuSO4 spectral filters is effective in reducing the height of a wide range of plants though plant carbohydrate status is also altered under CuSO4 filter. In previous studies, application of GA3 reversed both the reduction of plant height and carbohydrate status of CuSO4 spectral filter grown plants. It has been proposed that GAs enhance the activity of the enzyme sucrose phosphate synthase to regulate carbohydrate levels. In the present study the role of exogenously applied GA19, GA1, and GA3 in overcoming the reduction of plant height and carbohydrate levels was investigated. Chrysanthemum plants were treated weekly for 4 weeks with saturating doses of GA19, GA1 and GA3 (25 μg) or the growth retardants paclobutrazol and prohexadione. GA1 was also applied with paclobutrazol and prohexadione to assess whether response to GAs is altered under CuSO4 filter. GA1 and GA3 promoted growth similarly under control or CuSO4 filter. GA19 was least effective in promoting growth under CuSO4 filter. In summary, these results suggest that gibberellin physiology is altered under spectral filters with the conversion of GA19 a possible point of regulation. The correlation between the carbohydrate status and the growth of the plants will be discussed.

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

Effects of electron-withdrawing groups in imidazole-phenanthroline ligands and their influence on the photophysical properties of EuIII complexes for white light-emitting diodes

2017 ◽  
Vol 41 (18) ◽  
pp. 9826-9839 ◽  
Author(s):  
Boddula Rajamouli ◽  
Rachna Devi ◽  
Abhijeet Mohanty ◽  
Venkata Krishnan ◽  
Sivakumar Vaidyanathan
Keyword(s):  
Thin Film ◽  
Quantum Yield ◽  
White Light ◽  
Light Emitting Diode ◽  
Photophysical Properties ◽  
Red Light ◽  
Europium Complexes ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Phenanthroline Ligands

The red light emitting diode (LED) was fabricated by using europium complexes with InGaN LED (395 nm) and shown digital images, corresponding CIE color coordinates (red region) as well as obtained highest quantum yield of the thin film (78.7%).

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