Abstract Detail

Systematics Section/ASPT

Thureborn, Olle [1], Rydin, Catarina [2].

Phylogeny of Ephedra revisited.

Ephedra is with its approximately 60 species the largest of the three genera, which constitute the Gnetales. Ephedra is distributed in arid and semi-arid regions in northern Africa, Eurasia and North and South America, at elevations ranging from sea level up to 5000m (e.g., in the Himalayas and the Andes). Ephedra species are xeromorphic, usually dioecious, often erect or sprawling shrubs, but may also grow as vine-like shrubs or small trees. They are easily distinguished by their photosynthetic striate stems and much reduced scale-like leaves. While the morphological differences between the genera in Gnetales are substantial, the opposite can be said about the differences between species within Ephedra; they are very similar in overall morphology and to determine species can be difficult. Deep divergences in Ephedra have been addressed in several studies in the past and have proven difficult to resolve though it seems clear that a Mediterranean species complex with unclear internal relationship diverge early. One major reason for the difficulty in resolving the phylogeny is probably the low amount of sequence divergence within Ephedra, in combination with distant relationships to the closest living relatives of the genus. We approached these problems using an increased taxon sampling from the Mediterranean species complex and sequence data from nine gene regions: five plastid regions including one (matK) that previously has been sequenced only for a few taxa in the genus, and four nuclear regions including one (5’ETS) that has never been used in previous studies of phylogeny in Ephedra. Phylogenetic analysis reveals new insights into the deep divergences of Ephedra both in terms of credibility of results (posterior probability values) and resolution.

1 - Stockholm University, Department of Ecology, Environment and Plant Sciences, Lilla Frescativägen 5, Stockholm, SE-106 91, Sweden
2 - Stockholm University, Department of Ecology, Environment and Plant Sciences, Lilla Frescati 5, Stockholm, 10691, Sweden

Keywords:
Ephedra
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Gnetales
Phylogeny.

Presentation Type: Oral Paper:Papers for Sections
Session: 33
Location: Salon 10/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 9:15 AM
Number: 33006
Abstract ID:1010
Candidate for Awards:None