Abstract Detail

Bryology and Lichenology

Shaw, Jonathan [1], Piatkowski, Bryan [2], Duffy, Aaron [3], Aguero, Blanka [4], Nieto-Lugilde, Marta [5].

Comparative genomics, phylogenetics, and taxonomy of the Sphagnum magellanicum complex.

The U.S. Joint Genome Institute (JGI) has supported the development of genomic resources for the genus Sphagnum (peat moss) because of the ecological importance of this genus. As part of that effort a reference quality genome was developed for S. magellanicum, which has been interpreted as a widespread and common species throughout the world. Recent published work has shown that S. magellanicum comprises multiple species in Europe and that S. magellanicum s. str. is restricted to South America. We conducted further analyses based on whole genome resequencing and RADseq data and found that the S. magellanicum complex includes four species-level clades in North America, two of which also occur in Europe. The reference genome represents S. divinum, which is the only of the species in eastern North America that also occurs in western North America and northeastern Asia. Sphagnum magellanicum s. str. is restricted to southern South America, and plants in northern South America and Central America comprise a separate genetically divergent clade. An additional distinct clade occurs in China and Taiwan. The seven species we recognize in the S. magellanicum complex are characterized by tens of thousands (RADseq) to millions (genome resequencing) of fixed nucleotide differences, but also hybridize. We have identified 12 sites in eastern North America where two species co-occur. At least three of the species/clades worldwide are currently without names and have not likely been described. Molecular analyses resolve phylogenetic relationships among the species but that’s the easy part! Species are at best characterized by “soft” (overlapping) morphological differences and are not easy to distinguish. They do however differ in geographic ranges and ecological niches and a better understanding of their systematics will increase their value for ecological and evolutionary research.

1 - Duke University, Biology, 130 Science Drive, Box 90338, Durham, NC, 27708, United States
2 - Oak Ridge National Laboratory, Biosciences Division, 1 Bethel Valley Rd, Building 1507 Room 210, Oak Ridge, TN, 37830, United States
3 - Duke University, Biology, 130 Science Drive, Durham, NC, 27708
4 - Duke University, Biology, Box 90338, Durham, NC, 27708.0, United States
5 - Duke University, Biology, 130 Science Drive, Durham, NC, 27708, USA

Keywords:
peat moss
speciation
comparative genomics.

Presentation Type: Oral Paper
Number: BL1001
Abstract ID:110
Candidate for Awards:None