FREDERICQ, S1*, J.M. LOPEZ-BAUTISTA1, and R.L. MOE2. 1Dept. of Biology, University of Louisiana at Lafayette, Lafayette LA 70504-2451, USA; 2University Herbarium, VLSB 2465, University of California, Berkeley CA 94720-2465, USA. - New insights in the systematics of the Phyllophoraceae (Gigartinales, Rhodophyta)
.
The Phyllophoraceae, consisting of ~100 species worldwide, stands out
in exhibiting a wide spectrum of unique life history types that makes
it unusually interesting for assessing the phylogenetic importance of
reproductive traits relative to classification criteria. Type of life
history and position of the reproductive structures on the thallus
have traditionally formed the basis for separating eleven genera in
the Phyllophoraceae; however, phylogenetic analyses inferred from
three sets of DNA sequences [chloroplast-encoded rbcL, nuclear
large-subunit ribosomal RNA gene (LSU rDNA), and internal transcribed
spacer regions (ITS) of nuclear ribosomal DNA], instead indicate a
lack of correlation between type of life history and phylogenetic
relationships among the established taxa. This lack of correlation
dramatically challenges all of the traditional taxonomy, and we will
present a revised classification for the family that downplays life
history features. The study will answer the question which
morphological features can be used as meaningful indicators of
phylogenetic relationships in the Phyllophoraceae. The results will
also be addressed in light of global biogeographic hypotheses for the
family.
Key words: ITS, LSU rDNA, Phyllophoraceae, rbcL, Rhodophyta, systematics