ibclogo XVI International Botanical Congess


Abstract Number: 4774
Session = 3.7.3


INTEGRATING NEONTOLOGY AND PALEONTOLOGY IN PINUS


A. Liston, S.Ortiz-Garcia, P. Fields, Oregon State University, Corvallis, Oregon, USA, Univ. Nacional Autonoma de Mexico, Michigan State University, East Lansing, Michigan, USA


Morphological and molecular (650 bp of the nrDNA ITS region) phylogenetic analyses were conducted with 47 species of Pinus, representing the entire geographic range and all recognized subsections of the genus, and two outgroups. Comparisons of the resulting topologies highlight species of uncertain placement including Pinus nelsonii (a Mexican endemic with a unique combination of morphological features) and P. aristata (bristlecone pine). Conflicts between the data sets may be due to parallel evolution of cone and foliar characters. The fossil record is more congruent with molecular trees which hypothesize that subgenus Pinus is ancestral to subgenus Strobus. Molecular topologies support a Tethyan origin of the North American subsections of subgenus Pinus. Relationships among subsections of subgenus Strobus remain unresolved.


HTML-Version made 7. July 1999 by Kurt Stüber