Effect of flooding on annual dormancy cycles in buried seeds of two wetlandCarex species

Wetlands ◽  
1996 ◽  
Vol 16 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Carol C. Baskin ◽  
Edward W. Chester ◽  
Jerry M. Baskin
Keyword(s):  
Plant Biology ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 798-807 ◽  
Author(s):  
M. A. Copete ◽  
J. M. Herranz ◽  
P. Ferrandis ◽  
E. Copete

Plant Biology ◽  
2017 ◽  
Vol 19 (5) ◽  
pp. 818-823 ◽  
Author(s):  
T. G. S. Oliveira ◽  
I. P. Diamantino ◽  
Q. S. Garcia

1994 ◽  
Vol 72 (6) ◽  
pp. 779-782 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin

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.


1996 ◽  
Vol 74 (12) ◽  
pp. 2002-2005 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin

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.


2002 ◽  
Vol 12 (3) ◽  
pp. 181-191 ◽  
Author(s):  
Amanda J. Ellery

Changes in embryo dormancy of capeweed [Arctotheca calendula (L.) Levyns.] seeds in response to temperature were investigated to determine the nature of seasonal dormancy cycles. Primary embryo dormancy persisted for 2–3 months after seed collection and was then rapidly relieved when seeds were maintained at temperatures simulating summer soil surface temperatures. Embryo dormancy was also rapidly relieved in seeds maintained at constant temperatures, indicating that a daily temperature fluctuation was not necessary for the relief of embryo dormancy in capeweed. Dormancy relief was maximal at 40°C. Secondary dormancy was induced when seeds were maintained at low temperatures and a water potential of –1.5 MPa, suggesting that the onset of winter may postpone germination until a subsequent autumn. These results indicate that the dormancy cycles observed in capeweed seeds maintained on the soil surface are probably driven by seasonal changes in soil temperature.


2016 ◽  
Vol 57 (9) ◽  
pp. e153-e156
Author(s):  
Tori Vasquez ◽  
Brenda Sendejo
Keyword(s):  

Nature ◽  
1967 ◽  
Vol 213 (5076) ◽  
pp. 600-601 ◽  
Author(s):  
G. WESSON ◽  
P. F. WAREING

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