A Genebank for Western Australia's Threatened Flora
Volume 2 Number 9 - December 1997
The Threatened Flora Seed Centre was established by the West Australian Department of Conservation and Land Management less than 5 years ago as the State's principle long term seed storage facility for the conservation of rare and threatened taxa. The genebank was established with the help of staff from Australia's Commonwealth Scientific and Industrial Research Organisation's Australian Tree Seed Centre, using guidelines provided by the Royal Botanic Gardens Kew, Seed Bank and handbooks published by the International Plant Genetic Resource Institute.
The Centre's responsibility is to store seed of conservation taxa for indefinite periods of time, maintaining the highest possible viability, with the specific aim of maintaining the seed in long-term storage until the implementation of re-introduction programmes. Training was virtually 'on the job' for the original one staff member (the author), and the genebank was housed in a transportable building 10 m by 4 m, equipped with domestic refrigerator and freezer, two germination cabinets, a desiccator, some sieves and a computer.
Since that time in 1992, over 470 accessions in more than 175 taxa have been collected from the wild, tested and stored, with all information pertaining to provenance and maintenance meticulously databased. The genebank has expanded to house a drying room, walk-in coolroom (4oC) and freezer room (-20oC), and has a laboratory equipped to conduct basic research on seed germination and seed storage behaviour (Figures 1-3). There are now 2 full-time people working at obtaining genetically representative collections of native taxa and placing them into storage. Both staff members collect, test, store, and monitor seed, database information, conduct research and handle administration of the genebank. It is due to the vision and commitment of its staff and their colleagues that the genebank has expanded to its present capacity, and in 1996 the author was awarded a Churchill Fellowship to visit genebanks around the world (e.g. U.K., South Africa, U.S.A.).
Not all aspects of the establishment of the genebank have been easy, and some of the problems encountered have been related to the collection of seed from a variety of genera that exhibit differential fruiting and thus require collection over a long period of time. To counter this drain on resources, seed traps were designed to permit the efficient collection of seeds (Figure 3). This method of collecting has been very successful for a number of species in the genus Adenanthos (Proteaceae).
Seed from Western Australian plants are predominantly orthodox in nature, and have the potential to be stored successfully at reduced moisture contents and temperatures for long periods of time. Unfortunately, breaking the sometimes complex dormancy mechanisms that prevent germination of those seeds has at times proved problematic. In addition, seed of rare plants are often hard to obtain in sufficient quantities for comprehensive testing. Routine germination tests deplete seed accessions, and duplicating tests under different conditions is rarely possible with small sample sizes.
Despite these problems, our genebank efforts and research into seed biology have shown that the storage of seed from native species at low moisture contents and low temperature, without significant loss of viability, offers great potential for the conservation of rare and threatened genetic resources from Western Australia in the long term.
Seed banks are essential for ex situ conservation, and many botanic gardens contribute and collect seeds for storage. However, setting up a bank, collecting and maintaining viable and representative stocks is very challenging.
Seed Development and Germination
This text is intended for plant physiologists, molecular biologists, biochemists, biotechnologists, geneticists, horticulturalists, agronomists and botanists. It integrates advances in the diverse and rapidly-expanding field of seed science, covering both theoretical and applied knowledge.