Relationships, gene flow and species boundaries among New Zealand Fuscospora (Nothofagaceae: southern beech)

We analysed DNA profiles at eight simple sequence repeat (SSR) loci for 449 individuals of Fuscospora species from New Zealand. The two species with serrated leaves (F. fusca and F. truncata) are clearly distinct genetically despite the occurrence of wild hybrids. Further, from our results, we infer that they are no more closely related to each other than they are to either of the entire-leaved species (F. cliffortioides and F. solandri). Although genetic groups corresponding with F. cliffortioides and F. solandri can be distinguished, our data suggest that considerable admixture may occur between them in some areas. Nonetheless, the broadly sympatric distribution of these two genetic groups, and their consistency with morphological and ecological groups, support their recognition at species rank rather than their treatment as varieties of one variable species.