Phylogenetic relationships within Dendroligotrichum and Polytrichadelphus (Polytrichaceae, Polytrichopsida) in the Palaeoaustral region. Studies in austral temperate rainforest bryophytes 32

Abstract

Plastid trnT–F and atpB–rbcL spacer sequences as well as AFLP fingerprints are utilised to infer phylogenetic relationships of Dendroligotrichum and Polytrichadelphus taxa (Polytrichaceae) in the palaeoaustral region. Phylogenies based on DNA sequence data support the monophyly of each genus. Relationships within Dendroligotrichum remain ambiguous owing to low sequence divergence. AFLP fingerprinting, however, allows a clear distinction of all included Dendroligotrichum and Polytrichadelphus taxa at the species level. The morphological, distributional, ecological and molecular differences justify the recognition of the following three species in Dendroligotrichum: D. dendroides (Brid. ex Hedw.) Broth. and D. squamosum (Hook.f. & Wilson) Cardot in southern South America, as well as D. microdendron (Müll. Hal.) G.L.Sm. in New Zealand; and the following two species in Polytrichadelphus: P. magellanicus (Hedw.) Mitt. s.str. in southern South America and P. innovans (Müll. Hal.) A.Jäger in Australia and New Zealand. For Polytrichadelphus, the molecular topologies correspond with a vicariance scenario, with a basic split of taxa in the palaeoaustral region followed by migration of southern South American taxa northwards into the Neotropics. In Dendroligotrichum, substitutions and indels in the trnL intron and atpB–rbcL spacer are ambiguous in supporting either a basic split between the South American species and D. microdendron, similar to the one in Polytrichadelphus, or a trans-oceanic dispersal event between New Zealand and southern South America.