Bryological and Lichenological Section/ABLS
Forrest, Laura L. , Davis, E. Christine , Long, David G. , Stotler, Raymond E. , Crandall-Stotler, Barbara J. .
A molecular re-evaluation of diversity within Haplomitrium Nees (Marchantiophyta).
Nucleotide sequence data from eight nuclear, chloroplast and mitochondrial loci were obtained from 11 accessions of Haplomitrium (plus three Treubiaceae Verd.) in order to examine species level relationships within one of the earliest and most isolated land plant lineages. Phylogenetic analyses of the eight-locus matrix were conducted using maximum parsimony, maximum likelihood and homogeneous and heterogeneous Bayesian inference. In order to expand the sampling as far as possible, further analyses were conducted on subsets of the overall matrix that incorporated Haplomitrium sequences from GenBank. Every effort has been made to trace the geographic source of each GenBank submission, and as a result of this, many seemingly unrelated accessions have been discovered to belong to a few widely distributed Haplomitrium cultures. Our analyses indicate that there is a high degree of genetic divergence within Haplomitrium, and that the genus can be split into two major lineages. One of these consists of H. gibbsiae and H. chilensis. The North American population identified as H. hookeri is the earliest diverging member of the second lineage, while European and New Zealand H. hookeri form a well-supported clade, as do H. andinum, H. mnioides and H. blumii. This study has several taxonomic implications, including the recognition of H. andinum as separate from H. blumii, and the need for the re-evaluation of H. hookeri. Limited taxon sampling and the paraphyly of H. hookeri, however, create difficulties in tying the phylogeny in with the subgeneric classification of Bartholomew-Began.
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Bryophyte Web Page
1 - Southern Illinois University, Department of Plant Biology, 1125 Lincoln Drive, Carbondale, Illinois, 62901-6509, USA
2 - Duke University, Department of Botany, Box 90338, Durham, North Carolina, 27708-0338, USA
3 - Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, Scotland, EH3 5LR, United Kingdom
Presentation Type: Oral Paper
Date: Wednesday, August 17th, 2005
Time: 2:00 PM