Evolutionary relationships among pollinators and repeated pollinator sharing in sexually deceptive orchids

R. D. Phillips, G. R. Brown, K. W. Dixon, C. Hayes, C. C. Linde, R. Peakall

Research output: Contribution to journalArticle

10 Citations (Scopus)

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.

Original languageEnglish
Pages (from-to)1674-1691
Number of pages18
JournalJournal of Evolutionary Biology
Volume30
Issue number9
DOIs
Publication statusPublished - Sep 2017

Cite this

Phillips, R. D. ; Brown, G. R. ; Dixon, K. W. ; Hayes, C. ; Linde, C. C. ; Peakall, R. / Evolutionary relationships among pollinators and repeated pollinator sharing in sexually deceptive orchids. In: Journal of Evolutionary Biology. 2017 ; Vol. 30, No. 9. pp. 1674-1691.
@article{6cbf0622754b417baedb9be5b3bc6cb1,
title = "Evolutionary relationships among pollinators and repeated pollinator sharing in sexually deceptive orchids",
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 = "convergent evolution, phylogenetics, pollination, sexual deception, specialization, speciation, AUSTRALIAN FLORISTIC REGION, THYNNINE WASPS HYMENOPTERA, CALADENIA ORCHIDACEAE, SPECIALIZED POLLINATION, REPRODUCTIVE ISOLATION, DRIVEN SPECIATION, BEES HYMENOPTERA, CHEMICAL ECOLOGY, FLORAL ISOLATION, SOUTHERN AFRICA",
author = "Phillips, {R. D.} and Brown, {G. R.} and Dixon, {K. W.} and C. Hayes and Linde, {C. C.} and R. Peakall",
year = "2017",
month = "9",
doi = "10.1111/jeb.13125",
language = "English",
volume = "30",
pages = "1674--1691",
journal = "Journal of Evolutionary Biology",
issn = "1010-061X",
publisher = "Wiley-Blackwell",
number = "9",

}

Evolutionary relationships among pollinators and repeated pollinator sharing in sexually deceptive orchids. / Phillips, R. D.; Brown, G. R.; Dixon, K. W.; Hayes, C.; Linde, C. C.; Peakall, R.

In: Journal of Evolutionary Biology, Vol. 30, No. 9, 09.2017, p. 1674-1691.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Evolutionary relationships among pollinators and repeated pollinator sharing in sexually deceptive orchids

AU - Phillips, R. D.

AU - Brown, G. R.

AU - Dixon, K. W.

AU - Hayes, C.

AU - Linde, C. C.

AU - Peakall, R.

PY - 2017/9

Y1 - 2017/9

N2 - 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.

AB - 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.

KW - convergent evolution

KW - phylogenetics

KW - pollination

KW - sexual deception

KW - specialization

KW - speciation

KW - AUSTRALIAN FLORISTIC REGION

KW - THYNNINE WASPS HYMENOPTERA

KW - CALADENIA ORCHIDACEAE

KW - SPECIALIZED POLLINATION

KW - REPRODUCTIVE ISOLATION

KW - DRIVEN SPECIATION

KW - BEES HYMENOPTERA

KW - CHEMICAL ECOLOGY

KW - FLORAL ISOLATION

KW - SOUTHERN AFRICA

U2 - 10.1111/jeb.13125

DO - 10.1111/jeb.13125

M3 - Article

VL - 30

SP - 1674

EP - 1691

JO - Journal of Evolutionary Biology

JF - Journal of Evolutionary Biology

SN - 1010-061X

IS - 9

ER -