Plant Biol (Stuttg) 2007; 9(1): 147-151
DOI: 10.1055/s-2006-924310
Short Research Paper

Georg Thieme Verlag Stuttgart KG · New York

Evidence for Inbreeding Depression in the Food-Deceptive Colour-Dimorphic Orchid Dactylorhiza sambucina (L.) Soò

N. Juillet1 , S. Dunand-Martin2 , L. D. B. Gigord1
  • 1Department of Ecology and Evolution, Biophore Building, University of Lausanne, 1015 Lausanne, Switzerland
  • 2Laboratoire de culture in vitro, Conservatoire et Jardins Botaniques - Ville de Genève, 1 chemin de l'Impératrice, 1292 Chambésy, Switzerland
Further Information

Publication History

Received: May 2, 2006

Accepted: May 23, 2006

Publication Date:
01 August 2006 (online)

Abstract

About one third of all orchid species are deceptive, i.e., not providing any reward to their pollinator. Such species often have lower visitation rates compared to rewarding relatives. This could result in lower levels of geitonogamous selfing and thus would provide an advantage in term of progeny fitness through inbreeding avoidance. This hypothesis could be tested by comparing the level of inbreeding depression between deceptive and rewarding orchids. However, due to the difficulty to raise orchids from seeds, few studies of inbreeding depression are available, and most are focused on very early life stages, such as seed mass or embryo viability. Here, we present the results from an experimental investigation of inbreeding depression in the deceptive flower-colour dimorphic Dactylorhiza sambucina, from in vitro cultivation to greenhouse soil transplantation. We found strong inbreeding depression at all recorded stages (i.e., germination and survival), with estimates ranging from 0.47 to 0.75. Our study finally proposes a simple and suitable experimental protocol to raise orchids from seeds with high germination rates.

References

  • 1 Ågren J., Schemske D. W.. Outcrossing rate and inbreeding depression in two annual monoecious herbs, Begonia hirsuta and B. semiovata.  Evolution. (1993);  47 125-135
  • 2 Arditti J., Abdul Ghani A. K.. Numerical and physical properties of orchid seeds and their biological implications.  New Phytologist. (2000);  145 367-421
  • 3 Barrett S. C. H.. The evolution of plant sexual diversity.  Nature Reviews Genetics. (2002);  3 274-284
  • 4 Charlesworth D., Charlesworth B.. Inbreeding depression and its evolutionary consequences.  Annual Reviews of Ecology and Systematics. (1987);  18 237-268
  • 5 Dressler R. L.. The Orchids: Natural History and Classification. Cambridge, Massachussets; Harvard University Press (1981)
  • 7 Ferdy J. B., Loriot S., Sandmeier M., Lefranc M., Raquin C.. Inbreeding depression in a rare deceptive orchid.  Canadian Journal of Botany. (2001);  79 1181-1188
  • 8 Gigord L., Macnair M., Smithson A.. Negative frequency-dependent selection maintains a dramatic flower color polymorphism in the rewardless orchid Dactylorhiza sambucina (L.) Soò.  Proceedings of the National Academy of Sciences of the USA. (2001);  98 6253-6255
  • 9 Gigord L. D. B., Macnair M. R., Stritesky M., Smithson A.. Experimental evidence for floral mimicry in a rewardless orchid.  Proceedings of the Royal Society London B. (2002);  269 1389-1395
  • 6 Gill D. E.. Fruiting failure, pollinator inefficiency, and speciation in orchids. Otte, D. and Endler, J. A., eds. Speciation and its Consequences. Sunderland, Massachussets; Sinauer (1989): 458-481
  • 10 Husband B. C., Schemske D. W.. Evolution and timing of inbreeding depression in plants.  Evolution. (1996);  50 54-70
  • 11 Jersáková J., Kindlmann P., Renner S. S.. Is the colour dimorphism in Dactylorhiza sambucina maintained by differential seed viability instead of frequency-dependent selection?.  Folia Geobotanica. (2006);  41 61-76
  • 12 Johnson S. D., Nilsson L. A.. Pollen carryover, geitonogamy, and the evolution of deceptive pollination systems in orchids.  Ecology. (1999);  80 2607-2619
  • 13 Johnson S. D., Peter C. I., Ågren J.. The effects of nectar addition on pollen removal and geitonogamy in the non-rewarding orchid Anacamptis morio.  Proceedings of the Royal Society of London Series B. (2004);  271 803-809
  • 14 Keller L. F., Waller D. M.. Inbreeding effects in wild populations.  Trends in Ecology and Evolution. (2002);  17 230-241
  • 16 Manly B. F. J.. Randomization, Bootstrap and Monte Carlo Methods in Biology. London; Chapman and Hall (1997)
  • 17 McKendrick S. L.. In vitro germination of orchids : a manual. Available from http://www.ceiba.org/documents/CFTCpropman.pdf. (2000)
  • 18 Mitchell R. B.. Growing hardy orchids from seed at Kew.  The Plantman. (1989);  11 152-169
  • 15 Neiland M. R. M., Wilcock C. C.. Fruit set, nectar reward, and rarity in the Orchidaceae.  American Journal of Botany. (1998);  85 1657-1671
  • 19 Nilsson L. A.. The pollination ecology of Dactylorhiza sambucina (Orchidaceae).  Nordic Journal of Botany. (1980);  1 461-480
  • 20 Nilsson L. A.. Orchid pollination biology.  Trends in Ecology and Evolution. (1992);  7 255-258
  • 22 Peakall R., Beattie A. J.. Ecological and genetic consequences of pollination by sexual deception in the orchid Caladenia tentaculata.  Ecology. (1996);  50 2207-2220
  • 23 Rasmussen H. N., Whigham D. F.. Seed ecology of dust seeds in-situ - a new study technique and its application in terrestrial orchids.  American Journal of Botany. (1993);  80 1374-1378
  • 24 Rasmussen H. N.. Terrestrial Orchids: From Seed to Mycotrophic Plant. Cambridge; Cambridge University Press (1995)
  • 21 R Development Core Team .R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-00-3. http://www.R-project.org. (2004)
  • 25 Smithson A.. The consequences of rewardlessness in orchids: reward supplementation experiments with Anacamptis morio (Orchidaceae).  American Journal of Botany. (2002);  89 1579-1587
  • 26 Smithson A.. Pollinator limitation and inbreeding depression in orchid species with and without nectar rewards.  New Phytologist. (2006);  169 419-430
  • 27 Smithson A., Juillet N., Macnair M. R., Gigord L. D. B.. Is there a positive relationship between phenotypic diversity and reproductive success in rewardless orchids?.  Ecology. (2006);  in press
  • 28 Tremblay R. L., Ackerman J. D., Zimmerman J. K., Calvo R. N.. Variation in sexual reproduction in orchids and its evolutionary consequences: a spasmodic journey to diversification.  Biological Journal of the Linnean Society. (2005);  84 1-54
  • 29 Vallius E.. Position-dependent reproductive success of flowers in Dactylorhiza maculata (Orchidaceae).  Functional Ecology. (2000);  14 573-579

N. Juillet

Department of Ecology and Evolution
University of Lausanne

1015 Lausanne

Switzerland

Email: nicolas.juillet@unil.ch

Editor: F. Salamini