High genetic diversity in a clonal relict Alexgeorgea nitens (Restionaceae): implications for ecological restoration

Abstract

The importance of genetic issues associated with the sourcing of propagules is increasingly recognised for successful ecological restoration. A consideration of life history traits has contributed to ‘best-guess’ scenarios on the appropriate location and desirable properties of local provenance source populations, but these can lack precision. For clonal species, population genetic structure and variation will depend on the balance between the extent and growth rate of asexual clones, sexual reproduction, pollen dispersal, and subsequent seed dispersal and recruitment. We assessed patterns of population genetic structure and variation for Alexgeorgea nitens (Nees) L. Johnston & B. Briggs (Restionaceae), a dioecious, clonal, perennial species, with novel life history traits. Our results show high levels of genetic diversity within populations, and surprisingly low levels of population differentiation (ΦST = 0.17). We suggest that the high genetic diversity observed within these populations reflects extensive pollen dispersal and successful seeding (sexual reproduction) and recruitment events, even though direct observations of seedling recruitment are rare. In this case, a ‘best-guess’ propagule-sourcing scenario based on life-history traits that appear to limit dispersal capability does not predict the extent of high local genetic diversity and weak population genetic structure in A. nitens.