Abstract Detail

Pteridological Section/AFS

Huiet, Layne [1], Smith, A. R. [1].

Phylogenetic relationships in Adiantum inferred from chloroplast coding and non-coding sequences.

The genus Adiantum (Pteridaceae: Adiantoideae) comprises over 200 species and occurs o­n every continent except Antarctica. However most species are found in tropical to subtropical regions, with the greatest diversity and most recent radiations occurring in the Neotropics. Previous molecular phylogenetic analyses have shown that Adiantum is most closely related to members of the Vittariaceae. A monographic treatment of the genus has never been undertaken; however Hooker and, much later, Tryon and Tryon proposed species groupings. These groups have been used as a framework for sampling the genus worldwide to determine if they are supported by molecular analyses. The chloroplast gene rps4 and the adjacent rps4-trnS intergenic sequences have been used for this phylogenetic analysis. Results of the analysis for over 40 species have shown that the A. philippense, tetraphyllum, and platyphyllum groups appear to be monophyletic, while the A. patens, pectinatum, and capillus-veneris groups are polyphyletic. The blade morphology found in A. capillus-veneris occurs in at least three clades, o­ne of which comprises Old World species from which the A. reniforme group derives. Adiantum capillus-veneris appears to be the most basal member of the genus and is uniquely defined by an indel in rps4 that is not found in any other species. The phylogenies resulting from these analyses will be presented and their implications for the origins and relationships of Old and New World species discussed.

1 - University of California, Berkeley, University Herbarium, 1001 Valley Life Sciences Building, Berkeley, California, 94720

Keywords:
Adiantum
pteridophyte
rps4.

Presentation Type: Paper
Session: 10-4
Location: Superior B (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 10:15 AM
Abstract ID:697