| Title: | "Pollinator specificity, floral odour chemistry and the phylogeny of Australian sexually deceptive Chiloglottis orchids: implications for pollinator-driven speciation" |
| Author(s): | Peakall R; Ebert D; Poldy J; Barrow RA; Francke W; Bower CC; Schiestl FP; |
| Address: | "Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, ACT, Australia. rod.peakall@anu.edu.au" |
| DOI: | 10.1111/j.1469-8137.2010.03308.x |
| ISSN/ISBN: | 1469-8137 (Electronic) 0028-646X (Linking) |
| Abstract: | "* Sexually deceptive orchids are predicted to represent a special case of plant speciation where strong reproductive isolation may be achieved by differences in floral scent. * In this study of Australian sexually deceptive Chiloglottis orchids, we performed choice experiments to test for wasp pollinator specificity in the field; identified the compounds involved in pollinator attraction by gas chromatography with electroantennographic detection (GC-EAD), gas chromatography with mass selective detection (GC-MS), chemical synthesis and behavioural bioassays; and mapped our chemical findings on to a phylogeny of the orchids. * Field experiments confirmed pollination is a highly specific interaction, but also revealed a pool of nonpollinating 'minor responder' wasps. Six novel compounds, all 2,5-dialkylcyclohexan-1,3-diones, called 'chiloglottones', were discovered to be involved in pollinator attraction. Bioassays confirmed that pollinator specificity has a strong chemical basis, with specificity among sympatric orchids maintained by either different single compounds or a variation in a blend of two compounds. The phylogenetic overlay confirmed that speciation is always associated with pollinator switching and usually underpinned by chemical change. * If the chemical differences that control reproductive isolation in Chiloglottis have a strong genetic basis, and given the confirmed pool of potential pollinators, we conclude that pollinator-driven speciation appears highly plausible in this system" |
| Keywords: | "Animals Australia Biological Assay Choice Behavior Chromatography, Gas Cyclohexanones/analysis/chemistry Flowers/*chemistry *Genetic Speciation Molecular Weight Odorants/*analysis Orchidaceae/*genetics *Phylogeny Pollination/*physiology Reproduction Speci;" |
| Notes: | "MedlinePeakall, Rod Ebert, Daniel Poldy, Jacqueline Barrow, Russell A Francke, Wittko Bower, Colin C Schiestl, Florian P eng Research Support, Non-U.S. Gov't England 2010/06/22 New Phytol. 2010 Oct; 188(2):437-50. doi: 10.1111/j.1469-8137.2010.03308.x. Epub 2010 Jun 7" |
