Hauk, Warren .
Phylogenetic studies of Ophioglossaceae based on analyses of three plastid DNA data sets and morphology.
Phylogenetic relationships among 56 species of Ophioglossaceae were investigated using plastid DNA sequence data from the rbcL gene, the trnLUAA-FGAA intergenic spacer, and the rpL16 intron in combination with morphological characters. Eight of the nine major species groups in the family were represented. Initial alignments of trnL-F and rpL16 sequences were performed by Clustal X, but substantive adjustments by eye were necessary. Preliminary parsimony and maximum likelihood analyses showed that the four data sets, individually and combined, supported two main clades in the family: an ophioglossoid lineage and a botrychioid lineage. Within the botrychioid clade, Helminthostachys was sister to a monophyletic Botrychium s.l., in which Botrychium s.s. and Sceptridium were sister. Japanobotrychium was sister to the Botrychium s.s. + Sceptridium clade, and contained the rare J. lanuginosum and the even rarer J. chamaeconium of Cameroon, the latter formerly aligned with Botrypus. The north temperate Botrypus virginianus and the South American Bp. cicutarium formed a clade sister to Botrychium s.s. + Sceptridium + Japanobotrychium, but Bp. strictus was sister to all other species of Botrychium s.l., thus rendering Botrypus paraphyletic. Within the ophioglossoid clade, the epiphytic Cheiroglossa and Ophioderma were sister, and these two were in turn sister to a monophyletic Ophioglossum s.s. Two well-supported clades were identified within Ophioglossum s.s.. One clade consisted of only African collections, and the second clade contained both North American and African collections. Ophioglossum s.s. species with ellipsoid/orbicular rhizomes did not form a monophyletic group in these analyses, but this rhizome form may represent the plesiomorphic condition in Ophioglossum s.s.
Log in to add this item to your schedule
1 - Denison University, Department of Biology, 100 W College Street, Granville, Ohio, 43023, USA
Presentation Type: Oral Paper
Date: Monday, August 15th, 2005
Time: 9:00 AM