Phylogeny and divergence time estimates for the fern genus Azolla (Salviniaceae)
Abstract
A phylogeny for all extant species of the heterosporous fern genus Azolla is presented
here based on more than 5000 base pairs of DNA sequence data from six plastid loci
(rbcL, atpB, rps4, trnL-trnF, trnG-trnR, and rps4-trnS). Our results are in agreement
with other recent molecular phylogenetic hypotheses that support the monophyly of
sections Azolla and Rhizosperma and the proposed relationships within section Azolla.
Divergence times are estimated within Azolla using a penalized likelihood approach,
integrating data from fossils and DNA sequences. Penalized likelihood analyses estimate
a divergence time of 50.7 Ma (Eocene) for the split between sections Azolla and Rhizosperma,
32.5 Ma (Oligocene) for the divergence of Azolla nilotica from A. pinnata within section
Rhizosperma, and 16.3 Ma (Miocene) for the divergence of the two lineages within section
Azolla (the A. filiculoides + A. rubra lineage from the A. caroliniana + A. microphylla
+ A. mexicana complex). © 2007 by The University of Chicago. All rights reserved.
Type
Journal articleSubject
Science & TechnologyLife Sciences & Biomedicine
Plant Sciences
Azolla
divergence time estimates
ferns
freshwater plants
heterospory
Salviniaceae
3 NONCODING REGIONS
NUCLEOTIDE-SEQUENCES
MOLECULAR EVOLUTION
ABSOLUTE RATES
EXTANT FERNS
DNA
BIOLOGY
CLASSIFICATION
NOSTOC
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https://hdl.handle.net/10161/21810Published Version (Please cite this version)
10.1086/519007Publication Info
Metzgar, JS; Schneider, H; & Pryer, KM (2007). Phylogeny and divergence time estimates for the fern genus Azolla (Salviniaceae).
International Journal of Plant Sciences, 168(7). pp. 1045-1053. 10.1086/519007. Retrieved from https://hdl.handle.net/10161/21810.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Kathleen M. Pryer
Professor of Biology

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