Current and Predicted Future Winter Warm Spells Would Affect Douglas Fir (Pseudotsuga menziesii (Mirb.), Franco) Seeds in the Early Stage of Germination More Than in the Late Stage of Germination

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).

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Germination of dimorphic seeds of Suaeda aralocaspica in response to light and salinity conditions during and after cold stratification

PeerJ ◽

10.7717/peerj.3671 ◽

2017 ◽

Vol 5 ◽

pp. e3671 ◽

Cited By ~ 4

Author(s):

Hong-Ling Wang ◽

Chang-Yan Tian ◽

Lei Wang

Keyword(s):

Salt Tolerance ◽

Temperature Regime ◽

Cold Stratification ◽

Dormancy Breaking ◽

Continuous Darkness ◽

Cold Desert ◽

Physiological Dormancy ◽

Black Seeds ◽

Seeds Germination ◽

Germination Stage

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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Dormancy breaking in Savin juniper (Juniperus sabina L.) seeds

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2010.004 ◽

2011 ◽

Vol 79 (1) ◽

pp. 27-29 ◽

Cited By ~ 5

Author(s):

Tadeusz Tylkowski

Keyword(s):

Temperature Regime ◽

Room Temperature ◽

Cold Stratification ◽

Germination Capacity ◽

Dormancy Breaking ◽

Vegetation Season ◽

Natural Stand ◽

Juniperus Sabina ◽

Germinated Seeds

Savin juniper (Juniperus sabina 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 20o/3oC layout, for 14 and 17 weeks respectively, is more effective than stratification at 15o/3oC. 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.

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Overcoming Dormancy and Enhancing Germination of Sphaeralcea munroana Seeds

HortScience ◽

10.21273/hortsci.46.12.1672 ◽

2011 ◽

Vol 46 (12) ◽

pp. 1672-1676 ◽

Cited By ~ 3

Author(s):

Olga A. Kildisheva ◽

R. Kasten Dumroese ◽

Anthony S. Davis

Keyword(s):

Soil Stabilization ◽

Boiling Water ◽

Soil Types ◽

Cold Stratification ◽

Germination Capacity ◽

Extreme Temperatures ◽

Dormancy Breaking ◽

Drought Tolerant ◽

Series Of Experiments ◽

Ecological Importance

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.

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

Horticulturae ◽

10.3390/horticulturae7110490 ◽

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.

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SOCIAL STRUCTURE OF ANCIENT RUSSIA

Вестник Адыгейского государственного университета, серия «Регионоведение» ◽

10.53598/2410-3691-2021-3-284-25-29 ◽

2022 ◽

pp. 25-29

Author(s):

Алена Владимировна Искрина

Keyword(s):

Social Structure ◽

Social Stratification ◽

Early Stage ◽

The State ◽

Historical Period ◽

Historical Events ◽

Main Research ◽

Stage Of Development ◽

Political Events ◽

The Social

В статье рассматриваются особенности формирования социальной стратификации Древней Руси на раннем этапе развития, этапы появления различных страт в зависимости от социально-политических событий с X по XII вв. Предметом исследования является процесс образования социальных страт в древнерусском государстве. Цель статьи - рассмотреть социальное устройство Древней Руси, определить и описать стратификацию и взаимодействие страт между собой, историю изучения данного вопроса, политические события, влияющие на данные процессы. Основным вопросом исследования явились исторические события, оказавшие влияние на формирование социальных страт с X по XII вв., появление социальных страт в данный исторический период и формы их взаимодействия. Отвечая на данный вопрос, автор приходит к выводу, что разложение патриархально-общинного строя, формирование феодального вассалитета, принципа майората, княжеской дружины и другие внутриполитические события повлияли на формирование социальных страт государства. В связи с данными историческими событиями удается проследить этапы происхождения социальных слоев населения, их состав, социальные функции в обществе и государстве. The paper examines the features of the social stratification of the Ancient system at an early stage of development, the stages of the emergence of various strata depending on political events from the 10th to the 12th centuries. The subject of this research is the process of the formation of social strata in the ancient European state. The purpose of the publication is to consider the social structure of Ancient Rus, to determine and describe the stratification and interaction of strata with each other, to study this issue, political events that affect these processes. The main research issue was the historical events that influenced the formation of social strata from the 10th to the 12th centuries, the emergence of social strata in a given historical period and the forms of their interaction. Answering this question, the author arrives at the conclusion that the disintegration of the patriarchal-communal system, the formation of a feudal vassalage, the principle of primacy, the princely squad and other internal political events influenced the formation of social strata of the state. In connection with these historical events, it is possible to trace the stages of the origin of social strata of the population, their composition, social functions in society and the state.

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

Seed Science Research ◽

10.1017/s0960258509301075 ◽

2009 ◽

Vol 19 (2) ◽

pp. 115-123 ◽

Cited By ~ 14

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.

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Dormancy-Breaking and Germination Requirements for Seeds of Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae), a Mesic Forest Tree with High Ornamental Potential

Forests ◽

10.3390/f10040319 ◽

2019 ◽

Vol 10 (4) ◽

pp. 319

Author(s):

Yuhan Tang ◽

Keliang Zhang ◽

Yin Zhang ◽

Jun Tao

Keyword(s):

Seed Dormancy ◽

Seed Bank ◽

Soil Seed Bank ◽

Natural Habitat ◽

Eastern China ◽

Forest Tree ◽

Germination Percentage ◽

Cold Stratification ◽

Dormancy Breaking ◽

Breaking Dormancy

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.

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Dormancy of apple embryos. Are starch and reserve protein changes related to dormancy breaking?

Canadian Journal of Botany ◽

10.1139/b84-314 ◽

1984 ◽

Vol 62 (11) ◽

pp. 2308-2315 ◽

Cited By ~ 5

Author(s):

Michelle Bouvier-Durand ◽

Alina Dawidowicz-Grzegorzewska ◽

Claudine Thévenot ◽

Daniel Come

Keyword(s):

Cold Treatment ◽

Moderate Temperature ◽

The Other ◽

Cold Stratification ◽

Dormancy Release ◽

Dormancy Breaking ◽

Germination Process ◽

Embryo Dormancy ◽

Reserve Protein ◽

Apple Seeds

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.

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Temperature Requirements for Seed Germination of Three Penstemon Species'

HortScience ◽

10.21273/hortsci.25.2.191 ◽

1990 ◽

Vol 25 (2) ◽

pp. 191-193 ◽

Cited By ~ 9

Author(s):

Phil S. Allen ◽

Susan E. Meyer

Keyword(s):

Seed Germination ◽

Incubation Temperature ◽

Marked Decrease ◽

Rocky Mountain ◽

Germination Percentage ◽

Cold Stratification ◽

Dormancy Breaking ◽

Primary Dormancy ◽

Temperature Requirements ◽

Seed Propagation

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.

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Analysis of break-even points of Polish regional airports

Transportation Overview - Przeglad Komunikacyjny ◽

10.35117/a_eng_17_12_03 ◽

2017 ◽

Vol 2017 (12) ◽

pp. 19-25

Author(s):

Wojciech Augustyniak

Keyword(s):

Early Stage ◽

Fixed Costs ◽

External Financing ◽

Main Research ◽

Regression Functions ◽

Break Even Point ◽

Minimum Volumes ◽

Regional Airports ◽

The Cost ◽

High Share

The problematic nature of the high costs of building terrestrial aviation infrastructure does not end after the planning phase and the construction of new airspace. After the infrastructure has been commissioned, the cost of its depreciation and maintenance over the years represents a significant contribution to the cost of operating the airport. The high share of fixed costs is a direct reason for strong leverage. As a result, it is imperative to provide external financing to young airports at an early stage of their development. Owners of companies managing the above-mentioned infrastructure should be vividly concerned about the earliest possible break-even point, and consequently, the burden of direct subsidizing aviation activities in the region. The purpose of this article is to analyze the profitability thresholds at Polish regional airports as a means to discuss possible minimum volumes and revenues that emerging airports need to achieve as they do not generate losses. The main research method is a tool based on regression functions.

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