Seed Conservation Centre
Introduction
The implementation of efficient conservation strategies for our native plant species is essential to stem the rapid loss of biodiversity throughout Australia. Of South Australia's 3,396 native vascular plant species, approximately 800 are considered to be threatened in their natural environments, and at least 25 species have become extinct since European settlement. In 2002 the Botanic Gardens of Adelaide established the Seed Conservation
Centre to assist in conserving South Australia's threatened flora,
using ex situ (outside natural environment) techniques and
integrating these collections with the State's in situ (within
natural environment) conservation programs. One of the key activities
at the Centre is to undertake seed collections of priority plant
species throughout South Australia, for the establishment of long-term
seed conservation collections and the development of seed germination
and storage protocols for collected species. The Seed Conservation
Centre is currently the only unit within South Australia dedicated
to this type of research with native plant species. Seed Collection
In 2003 the Botanic Gardens of Adelaide in partnership with the Royal Botanic Gardens Kew Millennium Seed Bank (UK) embarked on the SACRED Seeds Project (an acronym for the South Australian Collection of Rare and EnDangered Seeds). This project aims to collect seed from more than 1,000 of South Australia's native plant species, including 60% of the states threatened species by the 2010. Once a target species has been identified in the field, seed is harvested in a manner that ensures a genetic representation of the population is collected. No more than 20% of the available seed is collected (10% for threatened species), ensuring the long-term impact of seed collection on wild plant populations is minimal. It is however important that sufficient seed be collected, as routine viability and germination trials during the life of the collection use up a proportion of the stock. Once collected, seed is kept dry in breathable cotton or paper bags until it reaches the Seed Conservation Centre. So far more than 1,200 native South Australian plant species have been collected, including over 300 threatened species. The program is leading the way in ex situ plant conservation in Australia, and is also contributing to our knowledge of the South Australian flora. An example of this is the rediscovery of species including the Mountain Scurf-pea (Cullen microcephalum) that was presumed extinct in South Australia. The SACRED Seeds project is supported by a range of organisations throughout the State including Forestry SA, the Department for Environment and Heritage, SA Water, TPAG, private land owners and a number of specialist private plant practitioners. Seed ProcessingFollowing arrival at the Seed Conservation Centre, seeds are placed in a specialised drying room maintained at 15°C and 15% relative humidity. These conditions ensure slow, steady drying and minimise reductions in seed lot viability. Seeds are then cleaned to remove debris and foreign materials. For some species it is necessary to extract seed from pods or cones before cleaning can occur.
Seed Biology ReserchMany of our native plant species are difficult to grow from seed. It is important that if in the longer term the seed collections made by the Botanic Gardens of Adelaide are to be useful in species recovery and restoration programs that the biology of the seeds is understood. Scientists at the Seed Conservation Centre conduct research aimed at understanding the dormancy mechanisms of recalcitrant species and develop methods that allow seeds to be germinated. Seed StorageOnce dried, seeds are transferred to foil pouches, hermetically sealed and stored under low temperature conditions at -20°C. Although the storage life of seeds is variable, data suggests species producing orthodox (tolerant of desiccation and low temperature storage) seeds can be stored for over 100 years. To test viability and ensure storage conditions are not detrimental to collections, a sample of seed is tested twelve months after first being stored, with subsequent tests every five years. Alternative Conservation TechniquesIn some instances, seed from particular plant species may be recalcitrant to long-term storage. Alternatively limitations in population size may prevent sufficient seed being collected from wild populations. Under these circumstances, alternative ex situ conservation techniques including the tissue culture based methods of micropropagation and embryo culture are adopted. PartnershipsTo enhance its capacity to contribute to the conservation of South Australia's threatened flora, the Seed Conservation Centre has developed collaborative links with a number of external groups at a national and international level, including botanic gardens, universities and other research institutions. The Botanic Gardens of Adelaide is also involved is research focused on restoring and rehabilitating degraded environments.
Student Research ProjectsOpportunities are available for tertiary students to become involved in research projects at the Seed Conservation Centre. These range from small projects suitable for incorporation into undergraduate studies to more extensive projects suitable for a post-graduate level. Projects are focused on understanding seed biology issues for native Australian plants. For further information about student research projects please contact the Botanic Gardens of Adelaide |
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