The control over physiological dormancy break by gibberellins in Calibrachoa sellowiana (Sendtn.) Wijsman seeds are associated with polyamines

2021 ◽  
Vol 43 (12) ◽  
Author(s):  
L. O. Zandoná ◽  
A. P. Lando ◽  
D. Goeten ◽  
N. Steiner
Keyword(s):  
Physiological Dormancy

Physiological dormancy in seeds of tropical montane woody species in Hawai`i

2020 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Alvin Yoshinaga ◽  
Dustin Wolkis
Keyword(s):  
Woody Species ◽  
Physiological Dormancy

scholarly journals Practical Methods for Breaking Seed Dormancy in a Wild Ornamental Tulip Species Tulipa thianschanica Regel

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1765
Author(s):  
Wei Zhang ◽  
Lian-Wei Qu ◽  
Jun Zhao ◽  
Li Xue ◽  
Han-Ping Dai ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Combined Treatment ◽  
Individual Treatment ◽  
Cold Stratification ◽  
Slight Effect ◽  
Sowing Depth ◽  
Physiological Dormancy ◽  
Commercial Breeding ◽  
Breaking Seed Dormancy

The innate physiological dormancy of Tulipa thianschanica seeds ensures its survival and regeneration in the natural environment. However, the low percentage of germination restricts the establishment of its population and commercial breeding. To develop effective ways to break dormancy and improve germination, some important factors of seed germination of T. thianschanica were tested, including temperature, gibberellin (GA3) and/or kinetin (KT), cold stratification and sowing depth. The percentage of germination was as high as 80.7% at a constant temperature of 4 °C, followed by 55.6% at a fluctuating temperature of 4/16 °C, and almost no seeds germinated at 16 °C, 20 °C and 16/20 °C. Treatment with exogenous GA3 significantly improved the germination of seeds, but KT had a slight effect on the germination of T. thianschanica seeds. The combined treatment of GA3 and KT was more effective at enhancing seed germination than any individual treatment, and the optimal hormone concentration for the germination of T. thianschanica seeds was 100 mg/L GA3 + 10 mg/L KT. In addition, it took at least 20 days of cold stratification to break the seed dormancy of T. thianschanica. The emergence of T. thianschanica seedlings was the highest with 82.4% at a sowing depth of 1.5 cm, and it decreased significantly at a depth of >3.0 cm. This study provides information on methods to break dormancy and promote the germination of T. thianschanica seeds.

scholarly journals Morphological aspects of fruits, seeds, seedlings and in vivo and in vitro germination of species of the genus Cleome

2014 ◽  
Vol 36 (3) ◽  
pp. 326-335 ◽  
Author(s):  
Tatiana Carvalho de Castro ◽  
Claudia Simões-Gurgel ◽  
Ivan Gonçalves Ribeiro ◽  
Marsen Garcia Pinto Coelho ◽  
Norma Albarello
Keyword(s):  
Urban Areas ◽  
Native Species ◽  
Human Impacts ◽  
In Vitro Germination ◽  
Morphological Aspects ◽  
Physiological Dormancy ◽  
Cleome Spinosa ◽  
The Tropics

The genus Cleome is widely distributed in drier areas of the tropics and subtropics. Cleome dendroides and C. rosea are Brazilian native species that occur mainly in Atlantic Forest and sandy coastal plains, respectively ecosystems negatively affected by human impacts. Cleome spinosa is frequently found in urban areas. Many Cleome species have been used in traditional medicine, as C. spinosa. In the present work, was investigated C. dendroides, C. rosea and C. spinosa germinative behavior under in vivo conditions, as well as was established suitable conditions to in vitro germination and seedling development. The in vivo germination was performed evaluating the influence of temperature, substrate and light. It was observed that only C. spinosa seeds presents physiological dormancy, which was overcome by using alternate temperatures. The substrate influenced significantly the germination of C. rosea and the seeds of C. dendroides showed the highest germination percentages in the different conditions evaluated. The post-seminal development stages under in vivo and in vitro conditions were defined. It was observed that the development was faster under in vitro than in vivo conditions. An effective methodology for in vitro germination, enabling the providing of material to experiment on plant tissue culture was established to C. dendroides and C. spinosa.

Seed development in Malva parviflora: onset of germinability, dormancy and desiccation tolerance

2007 ◽  
Vol 47 (6) ◽  
pp. 683 ◽  
Author(s):  
Pippa J. Michael ◽  
Kathryn J. Steadman ◽  
Julie A. Plummer
Keyword(s):  
Moisture Content ◽  
Seed Development ◽  
Desiccation Tolerance ◽  
Dry Weight ◽  
Physical Dormancy ◽  
Seed Moisture Content ◽  
Physiological Maturity ◽  
Seed Moisture ◽  
Physiological Dormancy ◽  
Malva Parviflora

Seed development was examined in Malva parviflora. The first flower opened 51 days after germination; flowers were tagged on the day that they opened and monitored for 33 days. Seeds were collected at 12 stages during this period and used to determine moisture content, germination of fresh seeds and desiccation tolerance (seeds dried to 10% moisture content followed by germination testing). Seed moisture content decreased as seeds developed, whereas fresh (max. 296 mg) and dry weight (max. 212 mg) increased to peak at 12–15 and ~21 days after flowering (DAF), respectively. Therefore, physiological maturity occurred at 21 DAF, when seed moisture content was 16–21%. Seeds were capable of germinating early in development, reaching a maximum of 63% at 9 DAF, but germination declined as development continued, presumably due to the imposition of physiological dormancy. Physical dormancy developed at or after physiological maturity, once seed moisture content declined below 20%. Seeds were able to tolerate desiccation from 18 DAF; desiccation hastened development of physical dormancy and improved germination. These results provide important information regarding M. parviflora seed development, which will ultimately improve weed control techniques aimed at preventing seed set and further additions to the seed bank.

scholarly journals Non-Deep Physiological Dormancy in Seed and Germination Requirements of Lysimachia coreana Nakai

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 490
Author(s):  
Saeng Geul Baek ◽  
Jin Hyun Im ◽  
Myeong Ja Kwak ◽  
Cho Hee Park ◽  
Mi Hyun Lee ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Seed Viability ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Viability Test ◽  
Physiological Dormancy ◽  
Different Temperatures ◽  
Germination Requirements

This study aimed to determine the type of seed dormancy and to identify a suitable method of dormancy-breaking for an efficient seed viability test of Lysimachia coreana Nakai. To confirm the effect of gibberellic acid (GA3) on seed germination at different temperatures, germination tests were conducted at 5, 15, 20, 25, 20/10, and 25/15 °C (12/12 h, light/dark), using 1% agar with 100, 250, and 500 mg·L−1 GA3. Seeds were also stratified at 5 and 25/15 °C for 6 and 9 weeks, respectively, and then germinated at the same temperature. Seeds treated with GA3 demonstrated an increased germination rate (GR) at all temperatures except 5 °C. The highest GR was 82.0% at 25/15 °C and 250 mg·L−1 GA3 (4.8 times higher than the control (14.0%)). Additionally, GR increased after cold stratification, whereas seeds did not germinate after warm stratification at all temperatures. After cold stratification, the highest GR was 56.0% at 25/15 °C, which was lower than the GR observed after GA3 treatment. We hypothesized that L. coreana seeds have a non-deep physiological dormancy and concluded that 250 mg·L−1 GA3 treatment is more effective than cold stratification (9 weeks) for L. coreana seed-dormancy-breaking.

Structures restricting passage of water in the mature seeds of yellow-cedar (Chamaecyparis nootkatensis)

1998 ◽  
Vol 76 (8) ◽  
pp. 1458-1466 ◽  
Author(s):  
Eila Tillman-Sutela ◽  
Anneli Kauppi
Keyword(s):  
Seed Coat ◽  
Minor Effect ◽  
Surface Layers ◽  
Anatomical Structures ◽  
Chamaecyparis Nootkatensis ◽  
Physiological Dormancy ◽  
Blue Solution ◽  
A Minor ◽  
Epicuticular Wax Layer ◽  
Scanning Electron

Anatomical structures of seed surface layers and their role in impeding passage of water were studied for mature yellow-cedar (Chamaecyparis nootkatensis D. Don) seeds. The structures of the seed coat, nucellar layers, and megagametophyte of both dry and moistened, sectioned seeds were examined with a field emission scanning electron microscope. The anatomical details of resin-embedded seeds were studied by light or fluorescence microscopy using stained and unstained sections. The permeability of the structures exterior to the megagametophyte was analyzed by placing seeds in a Methylene Blue solution and examining them under a stereomicroscope. Results proved that the seed coat proper had only a minor effect on restricting passage of water. Penetration of staining solution was efficiently directed by the wing and epicuticular wax layer covering it, and by the large, impermeable nucellar cap. These structures, typical for yellow-cedar, essentially differed from those studied in Picea and Pinus seeds. Still, the most effective barrier to the penetration of water was in the junction formed by the megaspore membranes and the strong cuticle of the megagametophyte. These structures together with the phenolic nucellar tissues probably contribute to physiological dormancy in yellow-cedar seeds. Consequently, studies of the localization of dormancy should be focused on these layers rather than on the seed coat.Key words: conifer, seed coat, anatomy, scanning electron microscopy, imbibition.

Morphological and physiological dormancy in seeds of Aegopodium podagraria (Apiaceae) broken successively during cold stratification

2009 ◽  
Vol 19 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Filip Vandelook ◽  
Nele Bolle ◽  
Jozef A. Van Assche
Keyword(s):  
Low Temperature ◽  
Seedling Emergence ◽  
Early Spring ◽  
Temperate Climate ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Temperature Requirement ◽  
Physiological Dormancy ◽  
Chilling Period

AbstractA low-temperature requirement for dormancy break has been observed frequently in temperate-climate Apiaceae species, resulting in spring emergence of seedlings. A series of experiments was performed to identify dormancy-breaking requirements of Aegopodium podagraria, a nitrophilous perennial growing mainly in mildly shaded places. In natural conditions, the embryos in seeds of A. podagraria grow in early winter. Seedlings were first observed in early spring and seedling emergence peaked in March and April. Experiments using temperature-controlled incubators revealed that embryos in seeds of A. podagraria grow only at low temperatures (5°C), irrespective of a pretreatment at higher temperatures. Seeds did not germinate immediately after embryo growth was completed, instead an additional cold stratification period was required to break dormancy completely. Once dormancy was broken, seeds germinated at a range of temperatures. Addition of gibberellic acid (GA3) had a positive effect on embryo growth in seeds incubated at 10°C and at 23°C, but it did not promote germination. Since seeds of A. podagraria have a low-temperature requirement for embryo growth and require an additional chilling period after completion of embryo growth, they exhibit characteristics of deep complex morphophysiological dormancy.

Sensitivity cycling and its ecological role in seeds with physical dormancy

2009 ◽  
Vol 19 (1) ◽  
pp. 3-13 ◽  
Author(s):  
K.M.G. Gehan Jayasuriya ◽  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Life Cycle ◽  
Environmental Conditions ◽  
Common Phenomenon ◽  
Ecological Role ◽  
Dormancy Breaking ◽  
Physical Dormancy ◽  
Physiological Dormancy ◽  
Seed Coats

AbstractCycling of physically dormant (PY) seeds between states insensitive and sensitive to dormancy-breaking factors in the environment has recently been demonstrated inFabaceaeandConvolvulaceae, and it may be a common phenomenon in seeds with water-impermeable seed coats. In contrast to seeds of many species with physiological dormancy (PD), those with PY cannot cycle between dormancy and non-dormancy (ND). In this paper, we evaluate the role of sensitivity cycling in controlling the timing of germination of seeds with PY in nature, and show that sensitivity cycling in seeds with PY serves the same ecological role as dormancy cycling in seeds with PD. Thus, sensitivity cycling in seeds with PY ensures that germination in nature occurs only at (a) time(s) of the year when environmental conditions for growth are, and are likely to remain, suitable long enough for the plant to complete its life cycle or to form a perennating structure. Further, we describe the experimental procedures necessary to determine whether sensitivity cycling is occurring, and discuss briefly the possible relevance of sensitivity cycling to dormancy classification.

Regulation of seed dormancy by abscisic acid and DELAY OF GERMINATION 1

2015 ◽  
Vol 25 (2) ◽  
pp. 82-98 ◽  
Author(s):  
Bas J.W. Dekkers ◽  
Leónie Bentsink
Keyword(s):  
Abscisic Acid ◽  
Seed Dormancy ◽  
Plant Hormone ◽  
Complex Trait ◽  
Hormone Interactions ◽  
Physiological Dormancy ◽  
Recent Developments ◽  
Radicle Emergence ◽  
Dormancy Induction

AbstractPhysiological dormancy has been described as a physiological inhibiting mechanism that prevents radicle emergence. It can be caused by the embryo (embryo dormancy) as well as by the structures that cover the embryo. One of its functions is to time plant growth and reproduction to the most optimal season and therefore, in nature, dormancy is an important adaptive trait that is under selective pressure. Dormancy is a complex trait that is affected by many loci, as well as by an intricate web of plant hormone interactions. Moreover, it is strongly affected by a multitude of environmental factors. Its induction, maintenance, cycling and loss come down to the central paradigm, which is the balance between two key hormonal regulators, i.e. the plant hormone abscisic acid (ABA), which is required for dormancy induction, and gibberellins (GA), which are required for germination. In this review we will summarize recent developments in dormancy research (mainly) in the model plant Arabidopsis thaliana, focusing on two key players for dormancy induction, i.e. the plant hormone ABA and the DELAY OF GERMINATION 1 (DOG1) gene. We will address the role of ABA and DOG1 in relation to various aspects of seed dormancy, i.e. induction during seed maturation, loss during dry seed afterripening, the rehydrated state (including dormancy cycling) and the switch to germination.

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