Patterns of molecular divergence within the palaeoaustral genus Weymouthia Broth. (Lembophyllaceae, Bryopsida)

Abstract

Populations of Weymouthia mollis and cochlearifolia from New Zealand, as well as W. billardieri and W. mollis (Lembophyllaceae) from Patagonia were investigated to compare DNA sequence divergence and patterns of indel variation between populations. Sequence analysis also included a comparison with Lembophyllum divulsum. Sequence divergences of the markers investigated were extremely low. No divergence was found within populations, neither in the ITS2 (nrDNA) nor in the trnT_UGU–trnL_UAA–trnF_GAA (cpDNA) region. There is no molecular evidence to treat the southern South American W. billardieri as a separate species. This supports the view of synonymizing W. billardieri and W. cochlearifolia, as distinct morphological characters are lacking. The question of stenoevolution in Weymouthia remains unsettled, as additional data would be necessary to clarify this issue.