Onagraceae as a model experimental system
Raguso, Robert A. .
Evening perfumes: insights from scents and non-scents in the Onagraceae.
The scientific and common names of the Evening Primroses(Oenothera) call attention to the fragrant, night blooming habit of these remarkable plants. Early studies by Gregory and Stockhouse documented the effectiveness of large hawkmoths as pollinators of the outcrossing species of Oenothera, and circumstantial evidence suggested that odors play important roles in guiding such moths to flowers. In this talk, I summarize a decade of collaborative studies aimed at understanding (1) how floral scent guides hawkmoths to Oenothera and similar night-blooming flowers, (2) how scent varies amongrelated taxa that differ in breeding system or pollinator spectrum, and (3) how phylogenetic history shapes the chemical composition of such floral scents,within and among lineages of Oenothera and other Onagraceae. Scent elicits flower-searching behavior by hawkmoths from a distance and, together with visual cues, guides floral approach and proboscis extension. Most outcrossing Oenothera species emit blends of nitrogenous volatile compounds (aldoximes that are precursors to mustard oils)with a sharp, rubbery scent, as well as sweet terpenoid alcohols (geraniol,linalool) and aromatic esters (methyl benzoate) common to hawkmoth-pollinated flowers worldwide, whereas autogamous or day-blooming species in the same lineages (e.g. sect. Calylophus) tend to lack these odors. Finally, some scent compounds were found to be restricted to specific clades (e.g. methylnicotinate in sect. Lavauxia, 1,8-cineole in sects. Anogra + Kleinia)irrespective of flower size, pollinator spectrum or breeding system. Similar findings in comparable plant lineages (e.g. Mirabilis, Nicotiana) suggest that such compounds may serve different roles in floral defense or may simply indicate selectively neutral synapomorphies.
Log in to add this item to your schedule
1 - Cornell University, Neurobiology and Behavior, W355 Mudd Hall, 215 Tower Road, Ithaca, NY, 14853, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Lenox Room/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 2:30 PM