Autonomous self-pollination and insect visitation in a saprophytic orchid, Epipogium roseum (D.Don) Lindl.
X. Zhou A , H. Lin A , X.-L. Fan A and J.-Y. Gao A BA Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China.
B Corresponding author. Email: gjy@xtbg.org.cn
Australian Journal of Botany 60(2) 154-159 https://doi.org/10.1071/BT11265
Submitted: 19 October 2011 Accepted: 5 February 2012 Published: 9 March 2012
Abstract
Reproductive biology of saprophytic plants has been poorly studied. Epipogium roseum (D.Don) Lindl. is a small saprophytic orchid that is widely distributed in tropical and subtropical Asia, Australia and Africa. The floral biology and insect visitation of E. roseum were studied in Xishuangbanna, south Yunnan Province, China. E. roseum possesses an obligate self-pollination system, in which the degenerative rostellum has lost its function as a physical barrier separating the stigma and stamens (pollinia), allowing contact between the stigmatic secretions and the pollinia during bud development. Flowers of E. roseum usually open and successfully attract insect visitors. The Asian honey bee (Apis cerana cerana) was the only visitor observed, and regularly visited flowers of E. roseum for nectar. However, these bees did not carry pollinia away after visiting the flowers due to the absence of a viscid disk in E. roseum; the results of experiments also indicated that the Asian honey bee does not contribute to fruit set in E. roseum. The visiting frequency of Asian honey bees to flowers of E. roseum varied both spatially and temporally. E. roseum does not undergo outcrossing mediated by insects and is adapted to obligate self-pollination. We suggest that this may have evolved because of the uncertainty of pollinator services associated with its saprophytic lifestyle. Our current studies do not support the hypothesis that obligate autogamy is favoured by myco-heterotrophic plants due to resource limitations.
Additional keywords: obligate autogamy, Orchidaceae, pollinator services, relic floral features, saprophyte.
References
Arditti J (1990) ‘Orchid biology: reviews and perspectives.’ (Timber Press: Portland, OR)Barrett SCH (1985) Floral trimorphism and monomorphism in continental and island populations of Eichhornia paniculata (Speng.) Solms. (Ponteriaceae). Biological Journal of the Linnean Society. Linnean Society of London 25, 41–60.
| Floral trimorphism and monomorphism in continental and island populations of Eichhornia paniculata (Speng.) Solms. (Ponteriaceae).Crossref | GoogleScholarGoogle Scholar |
Barrett SCH (1996) The reproductive biology and genetics of island plants. Philosophical Transactions of the Royal Society B 351, 725–733.
| The reproductive biology and genetics of island plants.Crossref | GoogleScholarGoogle Scholar |
Bawa KS (1974) Breeding systems of tree species of a lowland tropical community. Evolution 28, 85–92.
| Breeding systems of tree species of a lowland tropical community.Crossref | GoogleScholarGoogle Scholar |
Cozzolino S, Widmer A (2005) Orchid diversity: an evolutionary consequence of deception? Trends in Ecology & Evolution 20, 487–494.
| Orchid diversity: an evolutionary consequence of deception?Crossref | GoogleScholarGoogle Scholar |
Dressler RL (1993) ‘Phylogeny and classification of the orchid family.’ (Dioscorides: Portland)
Furman TE, Trappe JM (1971) Phylogeny and ecology of mycotrophic achlorophyllous angiosperms. The Quarterly Review of Biology 46, 219–225.
| Phylogeny and ecology of mycotrophic achlorophyllous angiosperms.Crossref | GoogleScholarGoogle Scholar |
Jacquemyn H, Micheneau C, Roberts DL, Pailler T (2005) Elevation gradients of species diversity, breeding system and floral traits of orchid species on Re’union Island. Journal of Biogeography 32, 1751–1761.
| Elevation gradients of species diversity, breeding system and floral traits of orchid species on Re’union Island.Crossref | GoogleScholarGoogle Scholar |
Johnson SD, Edwards TJ (2000) The structure and function of orchid pollinaria. Plant Systematics and Evolution 222, 243–269.
| The structure and function of orchid pollinaria.Crossref | GoogleScholarGoogle Scholar |
Jones DL (1985) The self-pollination of Epipogium roseum (D. Don) Lindley. Orchadian 8, 91–92.
Lehnebach C, Robertson A, Hedderley D (2005) Pollination studies of four New Zealand terrestrial orchids and the implication for their conservation. New Zealand Journal of Botany 43, 467–477.
| Pollination studies of four New Zealand terrestrial orchids and the implication for their conservation.Crossref | GoogleScholarGoogle Scholar |
Levin DA (1972) Low frequency disadvantage in the exploitation of pollinators by corolla variants in Phlox. American Naturalist 106, 453–460.
| Low frequency disadvantage in the exploitation of pollinators by corolla variants in Phlox.Crossref | GoogleScholarGoogle Scholar |
Luo YB, Chen SC (2002) Critical notes on the genus Epipogium (Orchidaceae). Acta Phytotaxonomica Sinica 40, 449–452.
Ma YX, Liu YH, Zhang KY (1998) On microclimate edge of tropical rainforest fragments in Xishuangbanna. Acta Phytoecologica Sinica 22, 250–255.
Peter CI, Johnson SD (2009) Autonomous self-pollination and pseudo-fruit set in South African species of Eulophia (Orchidaceae). South African Journal of Botany 75, 791–797.
| Autonomous self-pollination and pseudo-fruit set in South African species of Eulophia (Orchidaceae).Crossref | GoogleScholarGoogle Scholar |
Real L (1983) ‘Pollination biology.’ (Academic Press: London)
Solbrig OT (1976) On the relative advantages of cross- and self-fertilization. Annals of the Missouri Botanical Garden 63, 262–276.
| On the relative advantages of cross- and self-fertilization.Crossref | GoogleScholarGoogle Scholar |
Takahashi H, Nishio E, Hayashi H (1993) Pollination biology of the saprophytic species Petrosavia sakuraii (Makino) van Steenis in central Japan. Journal of Plant Research 106, 213–217.
| Pollination biology of the saprophytic species Petrosavia sakuraii (Makino) van Steenis in central Japan.Crossref | GoogleScholarGoogle Scholar |
Taylor L, Roberts DL (2011) Biological Flora of the British Isles: Epipogium aphyllum Sw. Journal of Ecology 99, 878–890.
| Biological Flora of the British Isles: Epipogium aphyllum Sw.Crossref | GoogleScholarGoogle Scholar |
Tremblay RL, Ackerman JD, Zimmerman JK, Calvo RN (2005) Variation in sexual reproduction in orchids and its evolutionary consequences: a spasmodic journey to diversification. Biological Journal of the Linnean Society. Linnean Society of London 84, 1–54.
| Variation in sexual reproduction in orchids and its evolutionary consequences: a spasmodic journey to diversification.Crossref | GoogleScholarGoogle Scholar |
Tsi ZH, Chen SC (1995) Miscellaneous notes on orchids in Xishuangbanna of Yunnan, China. Acta Phytotaxonomica Sinica 33, 281–296.
Zhang D, Saunders R (2000) Reproductive biology of a mycoheterotrophic species, Burmannia wallichii (Burmanniaceae). Biological Journal of the Linnean Society. Linnean Society of London 132, 359–367.
