scholarly journals Overcoming Dormancy and Enhancing Germination of Sphaeralcea munroana Seeds

HortScience ◽  
2011 ◽  
Vol 46 (12) ◽  
pp. 1672-1676 ◽  
Author(s):  
Olga A. Kildisheva ◽  
R. Kasten Dumroese ◽  
Anthony S. Davis

The results of a series of experiments involving a variety of dormancy-breaking treatments indicate that Munro's globemallow [Sphaeralcea munroana (Douglas) Spach] seeds are physically dormant, possess a cap-like structure in the occlusion of the water gap, which inhibits imbibition, and can be artificially dislodged through boiling water scarification. The highest germination capacity (93%) was achieved by mechanical scarification of previously stored seeds. Exogenous application of a gibberellin solution and cold stratification failed to enhance germination compared with scarification alone, indicating an absence of additional dormancy types. These results should improve the usefulness of this drought-tolerant perennial for landscaping and restoration given its effectiveness in soil stabilization, tolerance to a variety of soil types, extreme temperatures, and ecological importance.

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 796
Author(s):  
Szymon Jastrzębowski ◽  
Joanna Ukalska ◽  
Adam Guziejko ◽  
Radosław Puchałka

Most tree species in the temperate climatic zone (including Douglas fir) disperse seeds in autumn. Some of them must be exposed to cold (0–10 °C) and moist conditions (cold stratification) to overcome dormancy and trigger germination. In the Northern Hemisphere, winter warm spells occur more frequently and last longer than in recent decades from eastern Canada to Europe. Our main research objective was to investigate the influence of current (1 or 3 days at day/night temperatures: 15 °C/10 °C) and future predicted (5 days at day/night temperatures: 25 °C/15 °C) winter warm spells on dormancy breaking and germination traits (germination energy—GE; germination capacity—GC; final germination capacity—FGC) of Douglas fir seeds from four old-growth stands in northern Poland. For this purpose, we interrupted cold stratification of seeds at different time points, i.e., after 3 weeks; 6 weeks; 9 or 3 weeks and 6 weeks; 3 and 9 weeks; 6 and 9 weeks; 3 and 6 weeks and 9 weeks. We found that for GE and GC, all main effects (populations—P; days of warm spell—D; stratification duration—W) and interactions were significant (except interaction P×D). FGC was significantly affected by the effects P and D and interactions of D × W and P × D × W. In addition, we found that the predicted warm spells negatively affected the early germination stage (GE and GC) of Douglas fir, but both current and future predicted winter conditions will not negatively affect the late germination stage (FGC).


2011 ◽  
Vol 79 (1) ◽  
pp. 27-29 ◽  
Author(s):  
Tadeusz Tylkowski

Savin juniper (<em>Juniperus sabina</em> L.) is a relict shrub in Poland with only one natural stand in Pieniny Mts. Seeds require warm followed by cold stratification to overcome dormancy. Application of temperature regime at 20<sup>o</sup>/3<sup>o</sup>C layout, for 14 and 17 weeks respectively, is more effective than stratification at 15<sup>o</sup>/3<sup>o</sup>C. Interruption of warm stratification phase after 7 weeks and seeds drying at room temperature for 3-days with warm stratification follow-on resulted in increasing of germination capacity from 25% to approximately 45%. Germinated seeds pricked to substrate into containers gave seedlings 3 cm high when cultivated under plastic tunnel in the first vegetation season.


Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 490
Author(s):  
Saeng Geul Baek ◽  
Jin Hyun Im ◽  
Myeong Ja Kwak ◽  
Cho Hee Park ◽  
Mi Hyun Lee ◽  
...  

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.


2009 ◽  
Vol 19 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Filip Vandelook ◽  
Nele Bolle ◽  
Jozef A. Van Assche

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.


Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 319
Author(s):  
Yuhan Tang ◽  
Keliang Zhang ◽  
Yin Zhang ◽  
Jun Tao

Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae) is an economically important tree in the temperate forests of Eastern China. In recent decades, ever-increasing use and modification of forestlands have resulted in major degeneration of the natural habitat of S. alnifolia. Moreover, S. alnifolia seeds germinate in a complicated way, leading to a high cost of propagation. The current study aimed to determine the requirements for breaking seed dormancy and for germination as well as to characterize the type of seed dormancy present in this species. Moreover, the roles of temperature, cold/warm stratification, and gibberellic acid (GA3) in breaking dormancy were tested combined with a study of the soil seed bank. The results showed that intact seeds of S. alnifolia were dormant, requiring 150 days of cold stratification to achieve the maximum germination percentage at 5/15 °C. Exposure of the seeds to ranges of temperatures at 15/25 °C and 20/30 °C resulted in secondary dormancy. Scarifying seed coat and partial removal of the cotyledon promoted germination. Compared with long-term cold stratification, one month of warm stratification plus cold stratification was superior in breaking dormancy. Application of GA3 did not break the dormancy during two months of incubation. Seeds of S. alnifolia formed a transient seed bank. The viability of freshly matured S. alnifolia seeds was 87.65% ± 11.67%, but this declined to 38.25% after 6-months of storage at room temperature. Seeds of S. alnifolia have a deep physiological dormancy; cold stratification will be useful in propagating this species. The long chilling requirements of S. alnifolia seeds would avoid seedling death in winter.


1984 ◽  
Vol 62 (11) ◽  
pp. 2308-2315 ◽  
Author(s):  
Michelle Bouvier-Durand ◽  
Alina Dawidowicz-Grzegorzewska ◽  
Claudine Thévenot ◽  
Daniel Come

During cold stratification of apple seeds both dormancy removal and initiation of the germination process occur. To characterize these two processes and to dissociate them from each other, two different cold treatments were used. One of them (cold treatment within the fruits) excluded the germination process, the other corresponded to classical stratification. Control treatments at moderate temperature were also applied. Starch accumulated in the radicle during breaking of embryo dormancy by stratification, whereas it disappeared when dormancy was broken inside the fruits. The comparison of starch changes at 0 and at 20 °C also showed that these changes cannot be related to dormancy release. Moreover, no proteolysis occurred whether dormancy was broken or not. Proteolysis observed during stratification of the embryos seemed to be linked to their imbibition (the first step of the germination). These data refute previous observations on this problem; they demonstrate that neither starch variations nor reserve protein changes can be related to breaking of embryo dormancy.


2020 ◽  
Vol 12 (17) ◽  
pp. 7226 ◽  
Author(s):  
Nishantha Bandara ◽  
Hiroshan Hettiarachchi ◽  
Elin Jensen ◽  
Tarik H. Binoy

The State of Michigan in the United States often encounters weak soil subgrades during its road construction and maintenance activities. Undercutting has been the usual solution, while a very few attempts of in-situ soil stabilization with cement or lime have been made. Compared to the large volume of weak soils that require improvement and the cost incurred on an annual basis, some locally available industrial byproducts present the potential to become effective soil subgrade stabilizers and a better solution from the sustainability perspective as well. The candidate industrial byproducts are Cement Kiln Dust (CKD), Lime Kiln Dust (LKD), and Fly Ash (FA), out of which only a fraction is currently used for any other secondary purposes while the rest is disposed of in Michigan landfills. This manuscript describes a laboratory investigation conducted on above industrial byproducts and/or their combinations to assess their suitability to be used as soil subgrade stabilizers in three selected weak soil types often found in Michigan. Results reveal that CKD or a combination of FA/LKD can be recommended for the long-term soil subgrade stabilization of all three soil types tested, while FA and LKD can be used in some soil types as a short-term soil stabilizer (for construction facilitation). A brief discussion is also presented at the end on the potential positive impact that can be made by the upcycling of CKD/LKD/FA on sustainability.


HortScience ◽  
1990 ◽  
Vol 25 (2) ◽  
pp. 191-193 ◽  
Author(s):  
Phil S. Allen ◽  
Susan E. Meyer

To determine optimum germination temperatures and effective dormancy-breaking procedures, field-grown (1983-85) seeds of `Bandera' Rocky Mountain penstemon (Penstemon strictus Benth), `Cedar' Palmer penstemon (Penstemon palmeri Gray), and firecracker penstemon (Penstemon eatonii Gray) were subjected to various cold stratification and incubation temperature treatments. Increased germination following an 8-week stratification occurred in seed lots containing dormant seeds, but a 2-week stratification generally failed to break dormancy. Older (1983) seeds of `Bandera' and `Cedar' penstemon germinated to full viability without stratification. All species showed a marked decrease in germination percentage above 20C; 15C consistently produced maximum germination after 4 weeks. At 15C, mean times to 90% of total germination were 11, 22, and 29 days for `Bandera', `Cedar', and firecracker penstemon, respectively. Transfer of seeds failing to germinate at warm temperatures (25 and 30C) to 15C and applying 720 μm gibberellic acid (GA3) solution was effective in breaking primary dormancy of firecracker penstemon and secondary dormancy of `Bandera' penstemon. Our findings suggest that incubation below 20C, combined with 8 weeks of stratification or the use of after-ripened seed, may improve seed propagation efforts for these species.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Edilma Pereira Gonçalves ◽  
Franklim Sales de Jesus Soares ◽  
Sérgio dos Santos Silva ◽  
Débora de Souza Tavares ◽  
Jeandson Silva Viana ◽  
...  

Ormosia arboreais a tree species planted in urban areas and used to restore degraded areas. Its seeds are dormant and propagation is difficult. This study compares different dormancy breaking methods and physiological seed quality and seedling production. The seeds were germinated in sand in the laboratory of the Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil. The following dormancy breaking treatments were applied: control (intact seeds), 100°C water immersion; boiling water immersion followed by 24 hours of soaking; scarification with number 100 and number 50 sandpaper opposite from root emergence; sulfuric acid immersion for 1 hour, 50, 45, and 30 minutes. Seed immersion in 100°C and boiling water did not break the dormancy. The study species showed a greater vigor of seedling when its seeds were submitted to treatments associated with tegument rupturing by sandpaper or sulfuric acid. On the other hand, seed scarification with sulfuric acid for 1 hour, 50, 45, and 30 minutes or sandpaper favored seed germination and vigor.


2015 ◽  
Vol 26 (2) ◽  
pp. 9-14
Author(s):  
Maciej Płatkowski ◽  
Arkadiusz Telesiński

AbstractThe aim of this study is to determine the effect of the two glyphosate salts: isopropylamine and potassium (contained in preparations Roundup) on the activity of phosphodiesterase and phosphotriesterase in the soil. The experiment was carried out in the laboratory conditions on two soil types: loamy sand (Corg 8.70 g·kg−1, pHKCl 6.39) and sandy loam (Corg 10.90 g·kg−1, pHKCl 6.81). Two glyphosate salts (isopropylamine and potassium) in dosage of 0, 1 and 100 mg·kg−1 were applicate into soils. Phosphodiesterase and phospotriesterase activities in soils were determined spectrophotometrically on days 1, 7, 14, 28, 56 and 112. The obtained results were converted with respect to the enzyme activities in the control soil (assuming it to be 100%) and given as percent of inhibition. The results were shown as environmental danger zones graphs. Obtained results showed that glyphosate salts application has primarily resulted in inhibition of phosphodiesterase activity, and stimulation of phosphotriesterase activity in soils. Soil type and kind of glyphosate salt affect the interaction of herbicide with phosphodiesterase and phosphotriesterase activities. The observed changes in the phosphodiesterase and phosphotriesterase activities caused by the addition of both glyphosate salts were located on environmental danger zones graphs in the range of negligible or acceptable values, which may indicate a low impact of herbicide on measured enzymes.


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