• Home
• Science Strategy
• Science Teams
• Projects
  • Ex Situ Conservation of Recalcitrant Seeds: Towards the Delivery of Target 8 of the GSPC
• People
• Publications
• Acronyms

Ex Situ Conservation of Recalcitrant Seeds: Towards the Delivery of Target 8 of the GSPC

Successful freezing of partially dried seeds depends on close control of cooling rates

This project is one of a series in the theme the 'Science of Seed Ageing’.

Recalcitrant seeds, which constitute about 3 to 47 % of the flora depending on habitat, are mainly confined to woody species, many of which are of considerable socio-economic importance in both tropical and temperate environments. Desiccation sensitivity in such material limits storage to a few months at ambient temperatures and moist conditions. Consequently, recalcitrant seeds pose the ultimate ex situ seed conservation challenge, requiring a balance between rate-limiting desiccation to specific water contents prior to temperature-dependent cooling and storage.  Whilst the cryopreservation of herbaceous apices has benefited from the development of a generic preservation method – specifically, utilising sucrose pretreatment, alginate bead encapsulation, rapid drying and recovery under in vitro conditions – no such reliable method is available for recalcitrant seed. The need to develop appropriate methods to support the conservation of species with limited desiccation tolerance has been highlighted in Target 8 of the Global Strategy for Plant Conservation (GSPC). The text notes that “threatened species in seed banks could be increased with additional resources, technology development and transfer, especially for species with recalcitrant seeds”. Recent improvements in the understanding of how environment impacts on the maximum potential desiccation tolerance in recalcitrant seeds at shedding and the resolution of critical moisture contents for desiccation stress has improved opportunities to manipulate the seeds post-harvest. We are taking numerous approaches including extraction and manipulation of embryonic axes of target species, particularly Australian Citrus sp., South African Amaryllidaceae and palms. We aim to develop methods applicable to a range of tissues and species. (See Annex 1 for 8 publications from this project).

Kew Home | Science Directory | Copyright & Privacy