Conservation genetics of Pimelea spinescens

Project summary

Pimelea spinescens comprises two subspecies. The type subspecies,spinescens, is known as the Spiny Rice-Flower and the other subspecies,pubiflora, is the Wimmera Rice-Flower. Spiny Rice-Flower is widespread but uncommon in Victoria, while Wimmera Rice-Flower is restricted to two populations in western Victoria. Both subspecies are small, spreading shrubs that occur in grassland or open shrubland. They are the subject of an integrated conservation program that includes genetic studies, translocation and reintroduction of plants, and investigation of root structure. Both subspecies are listed as critically endangered under the Federal Environment Protection Biodiversity Conservation Act 1999 (EPBC) and are also listed under theVictorian Flora and Fauna Guarantee Act 1988.

Wimmera Rice-Flower had not been collected since 1901, and was presumed to be extinct, until a population was discovered in 2005 in the Natimuk area. A second population has been located at Minyip, approximately 30 km from the Natimuk site. Numerous searches have been conducted to locate further populations based on existing herbarium records, but with no success to date. Plants have been sexed and are monitored regularly for flowering and seed set.

Spiny Rice-Flower is endemic to western Victoria where the 12,000 plants are found in approximately 20 populations. The expansion of urban Melbourne and changes to land use across its range impinge on populations and threaten their viability. Deborah Reynolds is undertaking a PhD study on the biology of the Spiny Rice-Flower.

Genetic markers (microsatellites) are being developed for Pimelea spinescensin collaboration with the Centre for Stress Adaptation Research and the Royal Botanic Gardens Sydney. These markers will provide further information on genetic variation across the species range. Leaf samples have been collected from both subspecies and DNA isolated for assessment of genetic variability.

Project team

  • Elizabeth James (Royal Botanic Gardens Melbourne)
  • Rebecca Jordan (Royal Botanic Gardens Melbourne, 2011–2013)
  • Pauline Rudolph (Department of Sustainability and Environment, Horsham)
  • Deborah Reynolds (PhD student, Victoria University)
  • Randall Robinson (Victoria University)
  • Pimelea spinescens Recovery Team

Support

  • Department of Sustainability and Environment, Victoria