Morphological and molecular variation in Conospermum triplinervium (Proteaceae), the tree smokebush: Implications for bushland restoration

Abstract

Ecological restoration benefits from information on population genetic structure and variation within a species to make informed decisions on where to source material of the local genetic provenance. Conospermum triplinervium is extremely rare in Bold Park, a large bushland remnant currently undergoing restoration in Perth, Western Australia. We sampled plants from Bold Park and six other native populations across the northern half of the species' range to assess patterns of morphological and genetic variation. There was considerable variation across six leaf measures with significant differentiation among some populations. The molecular data showed a high level of population structure (ΘB = 0.4974), with varying degrees of spatial overlap among populations in an ordination plot. Significant differentiation was observed among all pairs of populations, except for Bold Park and its geographically closest populations at Kings Park and Neerabup. These two populations had greater genetic variation (50.9% and 54.5% polymorphic markers, respectively) than did that at Bold Park (20.2%). The small Bold Park population would benefit from augmentation (via cuttings) from local plants. However, in the longer term, should the Bold Park population show evidence of declining viability, then material should be sourced from the genetically similar Kings Park population to increase genetic variation whilst also maintaining genetic integrity. © CSIRO 2008.