Molecular evidence for recognizing Antithamnion sparsum (Ceramiales, Rhodophyta) at the species level

Abstract

S.-R. Lee, I. K. Lee and Y. Suh. 2005. Molecular evidence for recognizing Antithamnion sparsum (Ceramiales, Rhodophyta) at the species level. Phycologia 44: 530–535.

The nucleotide sequences of rbcS and Rubisco spacer in the chloroplast genome, and the internal transcribed spacer (ITS) 1 and the small subunit ribosomal DNA in the nuclear genome were determined to clarify the taxonomic relationships of Antithamnion sparsum with its close allies. The species has been often considered to be conspecific with A. densum, but this taxonomic placement still remains to be confirmed. Phylogenetic analyses based on multiple molecular markers clearly distinguished A. sparsum from A. densum. In addition, the Atlantic A. densum from Kerry, Ireland, was clearly separated from the North Pacific A. defectum from San Juan Island, Washington. Comparative analyses of four DNA regions showed that the rbcS region provided the most useful information with the highest resolution and statistical support among the four DNA regions studied. Molecular evidence strongly suggests that A. sparsum should be treated as an independent species.

ACKNOWLEDGMENTS

This study was supported in part by a grant of KOSEF, Republic of Korea (M02-2003-000-20195-0) to S.R.L.