Evolutionary Developmental Biology (Evo-Devo)
Baker, Robert , Diggle, Pamela .
Making branches in Mimulus: intraspecific developmental variation inshoot architecture.
Shoot architecture is a fundamentally developmental aspect of plant biology with important implications for plant form, function, reproduction, and life history evolution. Mimulus guttatus is morphologically diverse and fast becoming a model species for evolutionary biology and ecology. Shoot architecture, however, has never been examined from a developmental perspectivein M. guttatus. We examined the development of branches and flowers over the course of ontogeny in plants from two locally adapted populations of M. guttatus with contrasting flowering times, life histories, and branch numbers. We find no evidence for direct trade-offs between flowers and branches, and flowering and branching are not limited by meristem number. All branches occur at the first four nodes in plants from both populations. Heterochronic processes are responsible for differences in branching and flowering at the 3rd and more distal nodes while differences in the frequency of branch outgrowth at the two basal most nodes are primarily responsible for population level differences in branch number. Histological and scanning electron microscope analyses demonstrate that plants from both populations initiate axillary meristems in similar numbers, and at similar locations and developmental stages. At the two basal most nodes, population level differences in branch number are most likely controlled by node-specific mechanisms governing meristem outgrowth.
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1 - University Of Colorado, Boulder, Ecology And Evolutionary Biology, Ramaley N122, Campus Box 334, University Of Colorado, Boulder, Boulder, CO, 80309, USA
2 - University Of Colorado, Department Of Ecology And Evolutionary Biology, CAMPUS BOX 334, University Of Colorado, Boulder, CO, 80309-0334, USA
life history evolution
Presentation Type: Oral Paper:Papers for Topics
Location: Lindell D/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 11:00 AM