conference NEW PERSPECTIVES ON THE SYSTEMATICS & ECOLOGY OF ORCHIDS

[Laure Civeyrel]

NEW PERSPECTIVES ON THE SYSTEMATICS & ECOLOGY OF ORCHIDS

18/20 November 2004

At the University of Toulouse
http://www.ladybio.ups-tlse.fr/Orchid-Symposium

Meeting Summary

Our knowledge of the Orchid family has recently undergone several
significant advances.

Concerning systematics, the first morphological classification was produced
by Swartz two centuries ago, and the latest by Dressler in 1993. Dressler's
classification is one of the most comprehensive morphologically-based
classifications to date. However, traditional morphologically based
classifications rely heavily on characters, which are often few, if not
unique, and can express considerable convergence due to ecological
selection. The use of molecular markers and cladistics methods has produced
a shift toward a more complex classification of Orchids. It provided strong
cladistical support to 5 subfamilies Apostasioideae, Cypripedioideae,
Vanniloideae, Orchidoideae and the Epidendroideae within the Orchidaceae,
but leaves aside some unresolved relationships at lower levels.

To fulfil their life cycle, orchids use two kinds of symbionts, i.e. insects
for pollination and fungi for hydro-mineral nutrition: in both cases,
cheating strategies repeatedly arose during orchid evolution. Insect-orchid
relationships have been well studied at the biochemical and physiological
level, and are believed to drive speciation in at least some cases.
Non-rewarding orchids, either devoid of nectar or acting as mate mimicry,
provide good models for the study evolution of mutualism. Underground
association with fungi (mycorrhizae) are necessary for the development of
orchids, especially at germination, when the fungus provides both mineral
and carbon resources to the reserveless seedling. The latter strategy lasts
up to adulthood in mycoheterotrophic, achlorophyllous species. Current
research using molecular techniques has clarified fungal identity and
specificity level in various associations, but the exact nature of the
relationship with the fungi often remains unclear.

This meeting will highlight new developments on the phylogenetic
classification, ecology and evolution of Orchids, as well as their
implications in the field of biodiversity conservation.

Organised by Dr Laure Civeyrel, Dr. Marc-Andre Selosse , Prof. Guy Durrieu
and Dr Gerard Joseph.

 

Speakers include: 

Mark Chase, Royal Botanical Gardens, Kew,

Mike Fay, Royal Botanical Gardens, Kew

Further information and registration details can be found on the website
http://www.ladybio.ups-tlse.fr/Orchid-Symposium Or contact Laure Civeyrel on
npseo at cict.fr 

Laure Civeyrel
tel +33 (0)561 55 67 50
fax +33 (0)561 55 61 96
web http://www.ladybio.ups-tlse.fr/Orchid-Symposium
LAboratoire DYnamique de la BIOdiversité
Universite Paul Sabatier, IV R3
118 Route de Narbonne
31062 Toulouse cedex 4, France