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

Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 340-343 ◽  
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.

Seasonal Changes in the Germination Responses of Buried Witchgrass (Panicum capillare) Seeds

Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 22-24 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seasonal Changes ◽  
Late Summer ◽  
Late Spring ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Late Autumn ◽  
Buried Seeds ◽  
Autumn And Winter

Buried seeds of witchgrass (Panicum capillare L., # PANCA) exposed to natural seasonal temperature changes in Lexington, KY, for 0 to 35 months exhibited annual dormancy/nondormancy cycles. Seeds were dormant at maturity in early October. During burial in late autumn and winter, fresh seeds and those that had been buried for 1 and 2 years became nondormant. Nondormant seeds germinated from 76 to 100% in light at daily thermoperiods of 15/6, 20/10, 25/15, 30/15, and 35/20 C, while in darkness they germinated from 1 to 24%. In late spring, seeds lost the ability to germinate in darkness, and by late summer 63 to 100% of them had lost the ability to germinate in light. As seeds became nondormant, they germinated (in light) at high (35/20, 30/15 C) and then at lower (25/15, 20/10, and 15/6 C) temperatures. As seeds reentered dormancy, they lost the ability to germinate (in light) at 15/6 C and at higher thermoperiods 2 to 3 months later.

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

2017 ◽  
Vol 198 ◽  
pp. 156-162 ◽  
Author(s):  
John Statton ◽  
Robert Sellers ◽  
Kingsley W. Dixon ◽  
Kieryn Kilminster ◽  
David J. Merritt ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Halophila Ovalis ◽  
Seed Dormancy And Germination

Germination requirements of Oenothera biennis seeds during burial under natural seasonal temperature cycles

1994 ◽  
Vol 72 (6) ◽  
pp. 779-782 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Seed Banks ◽  
Late Winter ◽  
Seasonal Temperature ◽  
Oenothera Biennis ◽  
Light Requirement ◽  
Term Survival ◽  
Temperature Changes ◽  
Buried Seeds ◽  
Dormancy Cycles

Buried seeds of Oenothera biennis, which have the potential to form long-lived seed banks, were investigated to determine whether or not they (i) undergo seasonal changes in their dormancy states and (ii) require light for germination. Seeds were buried in soil and exposed to natural seasonal temperature changes. Samples of seeds were exhumed at monthly intervals for 31 months and tested for germination in light and darkness at 12-h daily thermoperiods of 15:6, 20:10, 25:15, 30:15, and 35:20 °C. At maturity in autumn, seeds germinated to 84–95% in light at 30:15 and 35:20 °C, but to 0–69% at other test conditions. By late winter, seeds germinated to 95–100% at the five thermoperiods in light and in darkness. In summer and autumn, germination in light decreased at 15:6 °C, and in darkness it dropped to 0% at 15:6 °C and decreased at 20:10, 25:15, 30:15, and 35:20 °C. Following the second winter of burial, seeds germinated to near 100% at all thermoperiods in light and darkness. Thus, seeds exhibited an annual nondormancy – conditional dormancy cycle, being nondormant from midwinter to late spring and conditionally dormant in summer and autumn. Oenothera biennis is 1 of 10 species whose seeds live for 39–40 years or longer in soil and also have an annual conditional dormancy – nondormancy cycle. Seeds of six of these species, including O. biennis, can germinate in darkness in spring or summer at simulated habitat temperatures. Therefore, a light requirement for germination is not necessarily a prerequisite for long-term survival of buried seeds, and something other than darkness prevents germination of seeds of some species buried in soil. Key words: seed banks, buried seeds, germination, dormancy cycles, light requirement, Oenothera.

Role of temperature and light in the germination ecology of buried seeds of weedy species of disturbed forests. II. Erechtites hieracifolia

1996 ◽  
Vol 74 (12) ◽  
pp. 2002-2005 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Seed Bank ◽  
Full Range ◽  
Soil Disturbance ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Test Conditions ◽  
Buried Seeds ◽  
Weedy Species ◽  
Dormancy Cycles

At maturity in September, about half the seeds (achenes) of Erechtites hieracifolia (Asteraceae) collected in Kentucky were dormant (did not germinate at any test condition), whereas the others were conditionally dormant (germinated only at a narrow range of test conditions). Seeds sown on top of soil in an unheated greenhouse in September failed to germinate in autumn because temperatures were below those required for germination; however, they germinated at comparable temperatures the following spring. Seeds buried in soil in September 1987 and exposed to natural seasonal temperature changes were nondormant (germinated over full range of test conditions) by April 1988, but they entered conditional dormancy by October 1988. Each October through 1995, exhumed seeds exhibited conditional dormancy. Since 89% of the seeds were viable after 8 years of burial, it appears that although seeds of this species are wind dispersed, they also have the potential to form a long-lived seed bank. Thus, soil disturbance at any time from May to September could result in establishment of plants from seeds in the seed bank. Keywords: seed dormancy, Asteraceae, dormancy cycles, buried seeds, light.

Seed germination ecology of the endemic Iberian winter annualsIberis pectinataandZiziphora aragonensis

2009 ◽  
Vol 19 (3) ◽  
pp. 155-169 ◽  
Author(s):  
Miguel Á. Copete ◽  
José M. Herranz ◽  
Pablo Ferrandis
Keyword(s):  
High Temperatures ◽  
Natural Habitat ◽  
Ex Situ ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Germination Ecology ◽  
Physiological Dormancy ◽  
Seed Age ◽  
Winter Annual ◽  
Population Reinforcement

AbstractThe germination ecology of the winter annual Iberian endemicsIberis pectinataandZiziphora aragonensiswas investigated in order to better understand adaptations of rare species to their natural habitat and to improveex-situpropagation techniques and management of their habitat. Specifically, we analysed the following aspects: (1) influence of temperature, light conditions and seed age on germination patterns; (2) phenology of germination; (3) germinative response of buried seeds to seasonal temperature changes; and (4) temperature requirements for induction and breaking of secondary dormancy. Germination was substantially lower in darkness than with a photoperiod in both taxa, with this difference being more pronounced inZ. aragonensis. Freshly matured seeds showed conditional physiological dormancy, germinating at low and medium temperatures but not at high temperatures (28/14 and 32/18°C). Germination capability increased with time of dry storage in both species, suggesting the existence of non-deep physiological dormancy. Under greenhouse conditions, germination of both taxa was mostly concentrated in autumn (October–November), while spring percentages were less than 1% of total accumulated germination recorded during the study.I. pectinataandZ. aragonensisseeds buried and exposed to natural seasonal temperature variations in an unheated greenhouse came out of conditional dormancy in summer and re-entered it in winter, thus exhibiting an annual conditional dormancy/non-dormancy cycle. Dormant seeds of both species which were stratified at 28/14 or 32/18°C during an 8-week period, were non-dormant when they were subsequently incubated over a range of temperatures from 5 to 25/10°C. Non-dormant seeds were induced into dormancy when stratified at 5 or 15/4°C for 8 weeks, showing a particularly low germination response at high temperatures. Recommendations for wild-population reinforcement programmes and for the management of the natural habitat of both endemics are discussed.

Seasonal changes in germination responses of buried seeds of Verbascum thapsus and V. blattaria and ecological implications

1981 ◽  
Vol 59 (9) ◽  
pp. 1769-1775 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seasonal Changes ◽  
Growing Season ◽  
Seasonal Temperature ◽  
Verbascum Thapsus ◽  
Germination Characteristics ◽  
Buried Seeds ◽  
Ecological Implications ◽  
Successional Species ◽  
Summer Temperatures ◽  
Spring Temperatures

In a 2-year study buried seeds of Verbascum thapsus and V. blattaria were exposed to natural seasonal temperature cycles, and at monthly intervals they were exhumed and tested in light and darkness over a range of alternating temperatures simulating those in the habitat throughout the growing season. At any time from spring to early autumn, seeds of both species germinated in light at prevailing habitat temperatures. Seeds of V. blattaria germinated in darkness in spring at spring temperatures but did not germinate in darkness at any temperature in summer or autumn. Unlike V. blattaria, seeds of V. thapsus germinated to 25–85% in darkness in summer at summer temperatures. In the second spring of burial, seeds of both species showed a reduction in ability to germinate in darkness at spring temperatures. Only 5% of the V. blattaria and 16% of the V. thapsus seeds germinated while they were buried. The germination characteristics are discussed in relation to the ecology of these two early successional species.

A parametrized model of seasonal temperature changes in lakes

1990 ◽  
Vol 5 (1) ◽  
pp. 12-25 ◽  
Author(s):  
S.S. Zilitinkevich ◽  
V.A. Rumyantzev
Keyword(s):  
Seasonal Temperature ◽  
Temperature Changes

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

Botany ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document