The Peat Moss Sphagnum cuspidatum in Australia: Microsatellites Provide a Global Perspective

Abstract

The distribution of Sphagnum cuspidatum has been subject to controversy. Although historically reported from all continents except Antarctica recent authors consider S. citspidatum to be endemic to Europe and eastern North America. Microsateilites from Australian plants morphologically identified as S. cuspidatum were compared to microsatellites of plants morphologically identified as S. cuspidatum collected from other regions. The species was found to occur in Australia as well as on every continent except Antarctica. The sample most closely related to the Australian plants was collected in the Philippines, and samples from Australia, the Philippines, Colombia, and Equatorial Guinea formed a subclade within S. cuspidatum. Microsatellites further show that S. cuspidatum is one of the parental species of the double allopolyploid S. falcatulum, a Holantarctic species which is reported from Tasmania, New Zealand, and Chile.

The double allopolyploidSphagnum×falcatulum(Sphagnaceae) in Tierra del Fuego, a Holantarctic perspective

“…Although macroscopically and microscopically variable, the range of variation among TDF plants fell within that observed in allotriploid S. 6falcatulum on South Island, conforming to morphotypes associated with wetter microhabitats (Karlin et al, 2009(Karlin et al, , 2011b. Although typically branched, simplex morphotypes were present in both regions.…”

“…marker 9) when we consider all the alleles amplified per individual at a given microsatellite marker to be a collective unit, and 'locus' when the data are treated as being haploid (Karlin et al, 2009). Karlin et al (2009Karlin et al ( , 2011b found that it was possible to assign alleles at six microsatellite markers to the parental subgenomes (subgenome T and combined subgenomes R/S) in allotriploid S. 6falcatulum, with no genetic overlap (i.e. no shared alleles) between the parental subgenomes at these six markers.…”

“…Cuspidata species that have been reported for TDF suggests that morphological variation among plants of that subgenus is high in that region. The allotriploid cytotype of S. 6falcatulum is highly polymorphic (Fife, 1996;Karlin et al, 2009Karlin et al, , 2011b, with a simplex morphotype of S. 6falcatulum with efibrillose branch leaf hyaline cells (collected in New Zealand) having been described as a true moss (class Bryopsida) in the genus Drepanocladus (Allison, 1963, Ochyra & Bartlett, 1986. Roivainen (1937) found S. 6falcatu-lum to be morphologically variable in TDF, and noted that the variation included a simplex morphotype.…”

“…However, recent genetic studies have detected three subg. Cuspidata species in Australasia: S. cuspidatum, allodiploid S. 6falcatulum, and allotriploid S. 6falcatulum (Karlin et al, 2009(Karlin et al, , 2011b. Although genetically distinct, there is extensive morphological overlap among the three taxa.…”

Morphology informed by phylogeny reveals unexpected patterns of species differentiation in the aquatic moss Rhynchostegium riparioides s.l.

“…For instance, a combination of four loci including rbcL and matK allowed a species resolution of only 65% in a set of Chinese Grimmiaceae (Liu et al, 2011). More variable regions of the genome, and nuclear microsatellites in particular, have therefore increasingly been used in moss species-level systematics (e.g., Caruso et al, 2010;Harbaugh et al, 2011;Karlin et al, 2008Karlin et al, , 2011Korpelainen et al, 2008;Peros et al, 2011;Ramaiya et al, 2010).…”