Hybridization and ecological speciation in the salt tolerant Carex aquatilis lineage (Cyperaceae)

• Main Authors: Dragon, Julie A., Ashton, Paul, Dean, Mary, Cayouette, Jacques, Waterway, Marcia J.
• Format: Conference Object
• Language: unknown
• Published: 2009
• Subjects: QK Botany; Recta; Carex aquatilis; North Atlantic
• Online Access: http://repository.edgehill.ac.uk/2681/

From the most recent phylogeny of Carex section Phacocystis (Cyperaceae), generated from ITS, ETS, and psbA-trnH sequence data, a monophyletic clade of five flood-tolerant taxa was inferred and is herein referred to as the Carex aquatilis lineage (C. aquatilis, C. paleacea, C. subspathacea, C. salina, C. recta). Within the lineage, C. aquatilis in the broad sense is monophyletic, however, C. aquatilis in the strict sense is not, nor are the maritime members of the lineage. Although ecologically and molecularly divergent from C. aquatilis, the facultatively halophytic taxa have been suggested to be involved in the formation of numerous hybrids with facultatively glycophytic C. aquatilis. New molecular data, including sequence data and AFLP profiles, were used to improve the phylogenetic resolution within the lineage, to determine the parentage of suggested stabilized hybrids, to correlate genetic diversity with phenotypic and ecological diversity, and to infer the biogeographic history of the maritime populations on either side of the North Atlantic. Molecular and morphological differences are confirmed between the North American and Northern European populations of C. aquatilis, and which collectively are quite distinct from the maritime taxa. While morphologically distinct, gene flow continues to confound molecular signal within the maritime taxa of the lineage.