|
|
||||||||
Ecology |
2Department of Biology, P.O. Box 60, Middle Tennessee State University, Murfreesboro, Tennessee 37132 USA; 3Fakultas MIPA, Universitas Bengkulu, Bengkulu 38371, Indonesia; 4Faculty of Horticulture, Chiba University, Matsudo 271-8510, Japan
Osmorhiza aristata is an herbaceous perennial that grows primarily in Japan, through southern China, to the Himalayas. It closely resembles the eastern North American species O. claytonii and O. longistylis, and, together, the three species are an example of the well-known North AmericanAsian pattern of disjunction. Requirements for dormancy break and embryo growth were determined for seeds of O. aristata collected in Japan during the summers of 19982000. Embryos in fresh seeds were ca. 0.5 mm long, and they had to grow to 9 mm before the radicle emerged from the mericarp. Embryo growth and germination occurred during cold stratification at 5°C, the optimum temperature for germination. Gibberellic acid did not substitute for cold stratification. Thus, O. aristata seeds have deep complex morphophysiological dormancy (MPD). The type of MPD in O. aristata is similar to that in two western North American congeners but different from that in eastern North American congeners (nondeep complex MPD). Mapping the types of MPD onto a phylogeny of the genus suggests that nondeep complex MPD is derived from deep complex MPD. Although eastern North AmericanAsian disjuncts often exhibit morphological stasis, the taxa may differ greatly in physiological traits, such as seed dormancy.
Key Words: Apiaceae Asia disjunct taxa evolution morphological stasis morphophysiological dormancy North America Osmorhiza seed dormancy
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] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |