Seed storage and longevity of Australian plant species

[Truncated abstract] Ex situ seed storage is an important tool helping to conserve the world's plant biodiversity. The basic principles of long-term seed storage, reducing storage temperature and seed moisture content to increase seed longevity, have been known for a long time. These principles have been applied to develop genebank standards for the storage of plant species with orthodox seeds. Developed predominantly for the storage of agricultural species, they have increasingly been applied to a wide range of wild plants. Seeds of Australian species have been collected and stored since the earliest days of colonisation, however there is still scant information relating to the storability of Australian species. Despite the widespread adoption of the genebank standards at seed banks throughout Australia, there has been a suggestion that the recommended storage conditions may not be suitable for all Australian species. The Western Australian Department of Environment's Threatened Flora Seed Centre holds seed collections of the State's conservation significant plants in long-term storage. These collections provide a representative sample of the flora of not only Western Australia, but Australia as a whole. The suitability of applying international standards for long-term seed storage to the Australian flora was examined by reviewing seed-storage data from the Western Australian Threatened Flora Seed Centre. A high proportion of collections, representative of some of the most common genera in Australia, maintained viability in the short (<5 years) and medium (5–12 years) term. Declines in germination were evident for a small number of collections, however many of the declines were collection-specific and other collections of the same taxon did not decline. The longevity of two contrasting Australian species, Eucalyptus erythrocorys and Xanthorrhoea preissii, can be modelled using the improved seed viability equation using a one-step method.