Abstract Detail

Ecological and evolutionary attributes of bryophytes of the boreal and arctic regions: New paradigms from interdisciplinary research

Shaw, Blanka [1], Devos, Nicolas [2], Johnson, Matthew [3], Shaw, Jonathan [4].

Diversification of peat mosses: ecosystem engineers in northern wetlands.

In their seminal paper on the ecology of Sphagnum (peatmosses), Clymo & Hayward commented that ”The bulk of Sphagnum is greater than that of any other bryophyte genus (or perhaps of any other plant genus)…” Indeed, it is estimated that Sphagnum-dominated peatlands hold some 30% of the global terrestrial carbon pool even though they cover only about 5% of the land surface. Phylogenetic studies converge on the inference that the Sphagnopsida diverged from other mosses hundreds of millions of years ago, but recent analyses suggest that extant species of Sphagnum diversified much more recently, during the (late?) Tertiary. Sphagnum species are all very closely related, hampering resolution of deep relationships within the genus, but whole organellar genome sequences for the first time confidently resolve sister-group relationships among the subgenera. Comparative analyses of niche traits indicate that there is significant phylogenetic signal in species variation relative to the hummock-hollow gradient, but that for substrate pH, diversification conforms to a pattern suggesting stabilizing selection, and subgenera differ significantly in their rates of interspecific evolutionary change relative to pH. Transcriptome analyses provide evidence of a whole genome duplication that is shared by Sphagnum and the other three genera of Sphagnopsida. An ambitious genome sequencing effort is now underway in Sphagnum to link genome structure and function to ecologically important phenotypic traits, and through those traits to niche diversification underlying peatmoss speciation, and to carbon sequestration in peatlands.

1 - Box 90338, Durham, NC, 27708, USA
2 - Duke University, Biology, Box 90338, Durham, NC, 27708, USA
3 - Biology Department, 7033 1/2 N Sheridan Rd, Apt 2W, Chicago, IL, 60626, USA
4 - 130 Science Drive, Box 90338, Durham, NC, 27708, USA

Keywords:
Sphagnum
whole genome duplication
phylogenomics
Transcriptome
niche trait evolution.

Presentation Type: Symposium Presentation
Session: SY03
Location: Salon 10/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 10:15 AM
Number: SY03006
Abstract ID:422
Candidate for Awards:None