Maximising the value of seed collections for horticulture and conservation

Seed collection and processing can be a costly and time-consuming element of plant production and germplasm conservation. Understanding seed set, viability and germination, and responses to handling and storage conditions might provide information for decision-making relating to both horticultural plant production and long-term seed conservation. In this study, two species, Backhousia citriodora and B. myrtifolia were used to model how seed characteristics should be assessed. Commonly used in horticulture and readily available from Australian seed suppliers, anecdotal industry information suggested seed viability was an issue for both species. It was found that low seed set rather than seed viability was the reason for apparent low germination. Although seeds were found only in a small percentage of capsules, for B. citriodora 8-16.5% and for B. myrtifolia 20 and 35%, the extracted seed had relatively high germination rates; B. citriodora 74% and B. myrtifolia 94%. This finding underlines the importance of implementing ongoing seed quality assessment to maximise effectiveness of seed collection. In addition, an examination of storage options and seed longevity indicated that an alternative seed storage method such as cryopreservation should be considered to ensure long-term conservation of germplasm of these two species.