Polarity of peatmoss (Sphagnum) evolution: who says bryophytes have no roots?

Abstract

The class Sphagnopsida (Bryophyta) includes two genera: Ambuchanania and Sphagnum. Ambuchanania contains just one rare species known from two Tasmanian localities, but Sphagnum comprises a speciose clade of mosses that dominates many wetland ecosystems, especially in the boreal zone of the Northern Hemisphere. Recent phylogenetic analyses have resolved well-supported clades within Sphagnum, but polarizing Sphagnum evolution has been problematic because the genus is so isolated that it is difficult to determine homologies between morphological and/or molecular traits within Sphagnum with those of any potential outgroup. DNA sequences from 16 genomic regions representing the mitochondrial, chloroplast, and nuclear genomes (ca. 16 kilobases) were obtained from 24 species of Sphagnum plus one species each from Takakia and Andreaea in order to resolve a rooted phylogeny. Two tropical species, S. sericeum and S. lapazense, were resolved as sister to the rest of the genus and are extremely divergent from all other sphagna. The main Sphagnum lineage consists of two clades; one includes the sections Sphagnum, Rigida, and Cuspidata, and the other includes Subsecunda, Acutifolia, and Squarrosa. The placement of section Subsecunda is weakly supported, but other nodes are strongly supported by maximum parsimony, maximum likelihood, and Bayesian analyses. In addition to homogeneous Bayesian analyses, heterogeneous models were employed to account for different patterns of nucleotide substitution among genomic regions.

Can mosses serve as model organisms for forest research?

“…For instance, mosses are important contributors to bog formation and carbon trapping (Jones et al 1994;Shaw et al 2003) in peat lands, where almost 100 % of the ground layer is covered by mosses (Vitt and Wieder 2009) such as Sphagnum species. The relevance of biotechnology approaches regarding the production and cultivation of peat mosses is increasing due to the rising demand of peat as, e.g., substrate for horticulture (Beike et al 2015a).…”

A special issue of Phytotaxa dedicated to Bryophytes: The closest living relatives of early land plants

“…(Lindberg 1880: 25) Warnstorf (1900, Alaska (Photo: Blanka Shaw). Sphagnum comprises a speciose clade of mosses that dominates many wetland ecosystems, especially in the boreal zone of the Northern Hemisphere (Shaw et al 2003). In particular, Sphagnum is an important and conspicuous component in peatlands, which perform a significant global function in regulating the Earth's atmospheric chemistry as well as providing valuable economic commodities (Rochefort 2000).…”

Molecular and chemical characterization of a Sphagnum palustre clone: Key steps towards a standardized and sustainable moss bag technique

“…As for PCR-RFLP, a technique already applied in mosses (Vanderpoorten et al, 2003), several nuclear and plastid DNA regions (ITS, PsbC-TrnS and TrnF-V1) were tested by a set of 17 restriction enzymes before the anonymous regions RAPDa, RAPDb and RAPDf (Shaw et al, 2003), but no polymorphism was found. The double digestion of RAPDf with HinfI -HindIII derived in a characteristic, reproducible band pattern for the clone (Fig.…”

“…The anonymous DNA region RAPDf was amplified using the F-F and F-R primers and following the protocol reported in Shaw et al (2003). The PCR products were purified by GFX PCR DNA and Gel Band Purification Kit (Amersham Biosciences) and digested by a set of 17 restriction enzymes (Fermentas, Thermo Fisher Scientific) according to manufacturer's instructions.…”