|
|
||||||||
3 School of Biological Sciences, University of Kentucky, Lexington, Kentucky 40506-0225 USA; and 4 Department of Agronomy, University of Kentucky, Lexington, Kentucky 40546-0091 USA
In contrast to previous reports, the endocarps ("seed coats") of Sambucus species are not impermeable to water; thus, the seeds do not have physical dormancy. Seeds of the North American species Sambucus canadensis and S. pubens and of the European species S. racemosa have spatulate shaped embryos that are
60% fully developed (elongated) at seed maturity. The embryo has to extend to the full length of the seed to germinate. Embryos in freshly matured seeds of S. canadensis and in those of S. pubens grew better at 25°/15°C than at 5°C, whereas the rate of embryo growth in S. racemosa was higher at 5°C than at 25°/15°C. Seeds of all three species germinated to significantly higher percentages in light (14-h photoperiod) than in darkness. Fresh seeds of neither species germinated during 2 wk of incubation over a range of thermoperiods. Warm followed by cold stratification broke dormancy in seeds of S. canadensis and in those of S. pubens. Thus, seeds of these two North American species have deep simple morphophysiological dormancy (MPD). In comparison, seeds of the European species S. racemosa required a cold stratification period only for dormancy break, and thus they have intermediate complex MPD. GA3 was much more effective in breaking dormancy in seeds of S. racemosa than it was in those of S. canadensis or S. pubens.
Key Words: Caprifoliaceae embryo growth germination phenology imbibition morphophysiological seed dormancy Sambucus spp. underdeveloped spatulate embryo
This article has been cited by other articles:
![]() |
F. Vandelook, N. Bolle, and J. A. Van Assche Seed Dormancy and Germination of the European Chaerophyllum temulum (Apiaceae), a Member of a Trans-Atlantic Genus Ann. Bot., August 1, 2007; 100(2): 233 - 239. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Walck, S. N. Hidayati, and N. Okagami Seed germination ecophysiology of the Asian species Osmorhiza aristata (Apiaceae): comparison with its North American congeners and implications for evolution of types of dormancy Am. J. Botany, May 1, 2002; 89(5): 829 - 835. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. C. Baskin, O. Zackrisson, and J. M. Baskin Role of warm stratification in promoting germination of seeds of Empetrum hermaphroditum (Empetraceae), a circumboreal species with a stony endocarp Am. J. Botany, March 1, 2002; 89(3): 486 - 493. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. N. Hidayati, J. M. Baskin, and C. C. Baskin Dormancy-breaking and germination requirements for seeds of Symphoricarpos orbiculatus (Caprifoliaceae) Am. J. Botany, August 1, 2001; 88(8): 1444 - 1451. [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |