Developmental and Structural Section
Tomlinson, P. Barry , Huggett, , Brett .
Partial shoot reiteration in Wollemia nobilis; does it come from “axillary meristems”?
P. Barry Tomlinson, Harvard Forest, Harvard University, 324 N. Main St., Petersham, MA 01366 and The Kampong Garden of The National Tropical Botanical Garden, 4013 Douglas Rd., Miami FL 33133 and Brett Huggett Department of Evolutionary and Organismic Biology, Harvard University,16 Divinity Avenue, Cambridge MA 02138. In conifers reiteration either may be complete (repeating the whole shoot architecture) or partial (repeating only the morphology of higher-order branch axes). These new systems rarely arise from visible axillary reserve buds, but more commonly arise from minute axillary or detached meristems that undergo no further development until stimulated to form a new shoot apical meristem. These meristems have been little studied because they are elusive microscopically and their function requires detailed architectural understanding. The newly discovered (1994) Australian Wollemia nobilis provides good material to study the problem because of its precise architecture (Massart’s model) with highly contrasted orthotropic (trunk) and plagiotropic (branch) axes. Orthotropic axes demonstrably have numerous axillary meristems which can produce coppice shoots and have been useful in clonal propogation. Plagiotropic axes appear to be unbranched in adult trees but can reiterate in juvenile material either naturally or experimentally. However, search through many series of serial sections shows no evidence of axillary meristems, despite the precise location in which buds occur. How then do such buds originate? Is this an indication of the “memory” process by which axes in this tree are so strongly contrasted?
Log in to add this item to your schedule
1 - National Tropical Botanical Garden, The Kampong, Coconut Grove, Florida, 33133, USA
Presentation Type: Oral Paper:Papers for Sections
Location: 555B/Convention Center
Date: Wednesday, August 4th, 2010
Time: 11:15 AM