COSKUN, FATIH* and CLIFFORD R. PARKS. Department of Biology, CB# 3280, Coker Hall, UNC-Chapel Hill, NC 27599-3280. - Biogeography and Phylogeny of the genus Osmanthus (Oleaceae):evidence from nuclear ribosomal ITS DNA Sequences.
The classic biogeographic disjunct pattern, known as "the
Tertiary relict disjunction", has been of interest to botanists
for a long time, since the time of Linnaeus. The genus
Osmanthus, with its more than 25 species, demonstrates this
classic disjunct pattern, with a majority of the species of this genus
represented in eastern Asia, and the others in northern Turkey and in
south eastern United States. Green (1958) examined this genus
thoroughly in his monograph primarily based on morphological evidence.
In our study, we conducted a phylogenetic analysis to infer
relationships among the species of Osmanthus by using nuclear
ribosomal ITS DNA sequences. We sampled taxa from all the sections
recognized by Green (1958). After constructing the phylogeny of the
genus based on ITS DNA sequences, we compared current distribution of
the genus with inference from the DNA molecules and generated
biogeographic patterns for Osmanthus species.
Key words: Osmanthus , biogeography, ITS, Oleaceae, phylogeny, Tertiary disjunction