Biotechnology for saving rare and threatened flora in a biodiversity hotspot

Abstract

The Southwest Australian Floristic Region (SWAFR) is a plant biodiversity hotspot with a geographically isolated and predominantly endemic flora. Known threatening processes (i.e. excessive clearing of native vegetation, soil salinity, soil erosion and chronic weed infestation) combined with uncertain but potentially deleterious environmental (climate) changes pose great challenges for conservation and restoration efforts. With a paucity of nature reserves, in situ protection of species can be problematic. For many species, ex situ conservation becomes the only viable strategy for saving species from extinction via seed banking or living collections established through vegetative propagation, or tissue (in vitro) culture methods. Development of specific in vitro protocols is necessary to successfully initiate culture lines, with considerable development of nutrient media, plant growth regulator regimes and incubation conditions required to optimise shoot regeneration and multiplication, especially with woody species of the SWAFR. In addition, integration of root induction and acclimatization stages has allowed significant improvements in speed and success of plant production of both endangered and difficult-to-propagate woody species. We contend that there is also considerable potential for expansion of alternative in vitro technologies such as somatic embryogenesis for difficult taxa to complement existing ex situ conservation and restoration strategies in biodiversity hotspots such as SWAFR.