| Abstract Detail
Ecological Section Baskin, Jerry M. [1], Hidayati, Siti [2], Baskin, Carol C. [1]. Evolutionary considerations for seed dormancy in Dipsacales. Although the underdeveloped embryo, and thus morphological (MD) or morphophysiological (MPD) seed dormancy, is basal in angiosperms, it also occurs in advanced groups. A synthesis of the literature combining phylogeny and class of seed dormancy in the highly evolutionary-advanced order Dipsacales shows that MD (or MPD) occurs throughout all clades except the most advanced one, Valerina. Further, at least six levels of MPD are known in this order. Seeds of taxa in the Valerina clade have fully-developed embryos and physiological dormancy (PD) or no dormancy (ND); thus, PD and ND are derived conditions in Dipsacales. Assuming that class of seed dormancy in extant genera of Dipsacales has not changed through geological time, the fossil record suggests that MD/MPD was present in this lineage by the early Tertiary. Log in to add this item to your schedule
1 - University of Kentucky, Department of Biological Sciences, 101 Morgan Bld, Lexington, Kentucky, 40506-0225, USA 2 - Department of Biology, Po Box 60, Murfreesboro, Tennessee, 37132, USA
Keywords: Dipsacles evolution seed dormancy underdeveloped embryos.
Presentation Type: Oral Paper Session: 43-6 Location: Salon F - Austin Grand Ballroom/Hilton Date: Wednesday, August 17th, 2005 Time: 9:15 AM Abstract ID:37 |