Seed dormancy and germination of Halophila ovalis mediated by simulated seasonal temperature changes

AbstractSeed dormancy and germination ofSenna marilandicaandS. obtusifoliawere compared in greenhouse and laboratory studies. About 90% of theS. obtusifoliaseeds were green and had hard seed coat dormancy, whereas the other 10% were brown and nondormant. Seed-colour morphs did not occur inS. marilandica, and nearly 100% of the seeds had hard seed coat dormancy. Seeds ofS. obtusifoliawere significantly heavier than those ofS. marilandica. Mechanical scarification was very effective in overcoming dormancy in seeds of both species. However, concentrated sulfuric acid, absolute ethanol and boiling water were less effective in breaking dormancy in seeds ofS. marilandicathan in those ofS. obtusifolia. Further, incubating seeds at 30/15 to 40/25°C and dry-heat treatments at 80–100°C were ineffective in breaking dormancy inS. marilandica, but significantly increased germination percentages inS. obtusifolia. In neither species were simulated daily/seasonal temperature shifts effective in breaking dormancy. Scarified seeds of both species germinated over a wide range of temperatures in both light and darkness. Under near-natural temperature conditions, seeds ofS. marilandicagerminated in spring only, whereas those ofS. obtusifoliaemerged in late spring and throughout summer. Both species can form a long-lived seed bank. Dormancy break by high field temperatures in seeds ofS. obtusifoliaallows this species to germinate throughout the warm growing season and thus contributes to its success as a weed in arable crops.

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Does Seed Dormancy Play a Role in the Germination Ecology ofRumex crispus?

Weed Science ◽

10.1017/s0043174500082382 ◽

1985 ◽

Vol 33 (3) ◽

pp. 340-343 ◽

Cited By ~ 47

Author(s):

Jerry M. Baskin ◽

Carol C. Baskin

Keyword(s):

Seed Dormancy ◽

Growing Season ◽

Seasonal Temperature ◽

Rumex Crispus ◽

Temperature Changes ◽

Germination Ecology ◽

Buried Seeds ◽

Buried Seed

Seed dormancy does not play a role in the germination ecology of curly dock (Rumex crispusL. ♯ RUMCR). This study confirms reports that freshly matured seeds are nondormant, and it shows that buried seeds exposed to natural seasonal temperature changes remain nondormant. From October 1981 through June 1983, seeds exhumed at monthly intervals germinated 80 to 100% at all thermo-periods. These results do not support suggestions that seeds of curly dock buried in soil enter dormancy. However, the results do explain why seeds of this species in the Beal and Duvel buried-seed experiments germinated when exhumed at various times during the growing season.

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Seed Dormancy and Germination in Some Native Grasses 1

Agronomy Journal ◽

10.2134/agronj1944.00021962003600040008x ◽

1944 ◽

Vol 36 (4) ◽

pp. 337-345 ◽

Cited By ~ 13

Author(s):

C. J. Coukos

Keyword(s):

Seed Dormancy ◽

Native Grasses ◽

Seed Dormancy And Germination

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Seed dormancy and germination in Oenanthe stolonifera as affected by temperature and gibberellic acid

Horticulture Environment and Biotechnology ◽

10.1007/s13580-020-00292-0 ◽

2020 ◽

Author(s):

Hyun Jin Kim ◽

Haeyoung Na

Keyword(s):

Gibberellic Acid ◽

Seed Dormancy ◽

Seed Dormancy And Germination

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Regulation of Seed Dormancy and Germination Mechanisms in a Changing Environment

International Journal of Molecular Sciences ◽

10.3390/ijms22031357 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1357

Author(s):

Ewelina A. Klupczyńska ◽

Tomasz A. Pawłowski

Keyword(s):

Climate Change ◽

Seed Germination ◽

Seed Dormancy ◽

Environmental Conditions ◽

Global Climate ◽

Plant Evolution ◽

Suitable Habitat ◽

Climate Change Scenarios ◽

Adaptation Mechanism ◽

Seed Dormancy And Germination

Environmental conditions are the basis of plant reproduction and are the critical factors controlling seed dormancy and germination. Global climate change is currently affecting environmental conditions and changing the reproduction of plants from seeds. Disturbances in germination will cause disturbances in the diversity of plant communities. Models developed for climate change scenarios show that some species will face a significant decrease in suitable habitat area. Dormancy is an adaptive mechanism that affects the probability of survival of a species. The ability of seeds of many plant species to survive until dormancy recedes and meet the requirements for germination is an adaptive strategy that can act as a buffer against the negative effects of environmental heterogeneity. The influence of temperature and humidity on seed dormancy status underlines the need to understand how changing environmental conditions will affect seed germination patterns. Knowledge of these processes is important for understanding plant evolution and adaptation to changes in the habitat. The network of genes controlling seed dormancy under the influence of environmental conditions is not fully characterized. Integrating research techniques from different disciplines of biology could aid understanding of the mechanisms of the processes controlling seed germination. Transcriptomics, proteomics, epigenetics, and other fields provide researchers with new opportunities to understand the many processes of plant life. This paper focuses on presenting the adaptation mechanism of seed dormancy and germination to the various environments, with emphasis on their prospective roles in adaptation to the changing climate.

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A parametrized model of seasonal temperature changes in lakes

Environmental Software ◽

10.1016/0266-9838(90)90012-u ◽

1990 ◽

Vol 5 (1) ◽

pp. 12-25 ◽

Cited By ~ 3

Author(s):

S.S. Zilitinkevich ◽

V.A. Rumyantzev

Keyword(s):

Seasonal Temperature ◽

Temperature Changes

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Morphophysiological dormancy and germination ecology in diaspores of the subtropical palm Phoenix canariensis Chabaud

Botany ◽

10.1139/cjb-2021-0126 ◽

2021 ◽

Author(s):

Lanlan He ◽

Ganesh K. Jaganathan ◽

Baolin Liu

Keyword(s):

Seed Dormancy ◽

Seedling Emergence ◽

Primary Root ◽

Germination Percentage ◽

Early Summer ◽

Germination Ecology ◽

Phoenix Canariensis ◽

Morphophysiological Dormancy ◽

Cotyledonary Petiole ◽

Seed Dormancy And Germination

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.

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The Seasonal Cycle of Blocking and Associated Physical Mechanisms in the Australian Region and Relationship with Rainfall

Monthly Weather Review ◽

10.1175/mwr-d-13-00040.1 ◽

2013 ◽

Vol 141 (12) ◽

pp. 4534-4553 ◽

Cited By ~ 27

Author(s):

M. J. Pook ◽

J. S. Risbey ◽

P. C. McIntosh ◽

C. C. Ummenhofer ◽

A. G. Marshall ◽

...

Keyword(s):

Southern Ocean ◽

Seasonal Cycle ◽

Seasonal Temperature ◽

Ocean Fronts ◽

Temperature Changes ◽

Physical Mechanisms ◽

Australian Region ◽

Continental Antarctica ◽

Positive Correlations ◽

Blocking Index

Abstract The seasonal cycle of blocking in the Australian region is shown to be associated with major seasonal temperature changes over continental Antarctica (approximately 15°–35°C) and Australia (about 8°–17°C) and with minor changes over the surrounding oceans (below 5°C). These changes are superimposed on a favorable background state for blocking in the region resulting from a conjunction of physical influences. These include the geographical configuration and topography of the Australian and Antarctic continents and the positive west to east gradient of sea surface temperature in the Indo-Australian sector of the Southern Ocean. Blocking is represented by a blocking index (BI) developed by the Australian Bureau of Meteorology. The BI has a marked seasonal cycle that reflects seasonal changes in the strength of the westerly winds in the midtroposphere at selected latitudes. Significant correlations between the BI at Australian longitudes and rainfall have been demonstrated in southern and central Australia for the austral autumn, winter, and spring. Patchy positive correlations are evident in the south during summer but significant negative correlations are apparent in the central tropical north. By decomposing the rainfall into its contributions from identifiable synoptic types during the April–October growing season, it is shown that the high correlation between blocking and rainfall in southern Australia is explained by the component of rainfall associated with cutoff lows. These systems form the cyclonic components of blocking dipoles. In contrast, there is no significant correlation between the BI and rainfall from Southern Ocean fronts.

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