| Title: | Evolutionary relationships among pollinators and repeated pollinator sharing in sexually deceptive orchids |
| Author(s): | Phillips RD; Brown GR; Dixon KW; Hayes C; Linde CC; Peakall R; |
| Address: | "Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia. Kings Park and Botanic Garden, The Botanic Garden and Parks Authority, West Perth, WA, Australia. School of Plant Biology, The University of Western Australia, Nedlands, WA, Australia. Museum and Art Gallery of Northern Territory, Darwin, NT, Australia. Research Institute for Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia. Department of Agriculture and Environment, Curtin University, Perth, WA, Australia" |
| ISSN/ISBN: | 1420-9101 (Electronic) 1010-061X (Linking) |
| Abstract: | "The mechanism of pollinator attraction is predicted to strongly influence both plant diversification and the extent of pollinator sharing between species. Sexually deceptive orchids rely on mimicry of species-specific sex pheromones to attract their insect pollinators. Given that sex pheromones tend to be conserved among related species, we predicted that in sexually deceptive orchids, (i) pollinator sharing is rare, (ii) closely related orchids use closely related pollinators and (iii) there is strong bias in the wasp lineages exploited by orchids. We focused on species that are pollinated by sexual deception of thynnine wasps in the distantly related genera Caladenia and Drakaea, including new field observations for 45 species of Caladenia. Specialization was extreme with most orchids using a single pollinator species. Unexpectedly, seven cases of pollinator sharing were found, including two between Caladenia and Drakaea, which exhibit strikingly different floral morphology. Phylogenetic analysis of pollinators using four nuclear sequence loci demonstrated that although orchids within major clades primarily use closely related pollinator species, up to 17% of orchids within these clades are pollinated by a member of a phylogenetically distant wasp genus. Further, compared to the total diversity of thynnine wasps within the study region, orchids show a strong bias towards exploiting certain genera. Although these patterns may arise through conservatism in the chemical classes used in sex pheromones, apparent switches between wasp clades suggest unexpected flexibility in floral semiochemical production. Alternatively, wasp sex pheromones within lineages may exhibit greater chemical diversity than currently appreciated" |
| Keywords: | Animals *Biological Evolution Flowers *Orchidaceae *Phylogeny *Pollination Wasps convergent evolution phylogenetics pollination sexual deception specialization speciation; |
| Notes: | "MedlinePhillips, R D Brown, G R Dixon, K W Hayes, C Linde, C C Peakall, R eng Switzerland 2017/07/18 J Evol Biol. 2017 Sep; 30(9):1674-1691. doi: 10.1111/jeb.13125. Epub 2017 Jul 17" |
