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Frozen planet

The Frozen Planet research theme aims to develop predictive tools and low temperature protocols (cryopreservation) that optimise conditions for the successful conservation of tropical and temperate plants, especially threatened species such as cycads, orchids and palms.
Photo of plant dripping with icicles


Threats to plant species loss demand innovative conservation solutions that accommodate the varying levels of stress tolerance of seeds, from those that are highly tolerant of drying to those that are desiccation-sensitive, the latter being a particular feature of tropical moist forest species.

Our research is:

  • studying how complex mixtures of cryoprotectants can enable the cryopreservation of embryos with varying morphologies and nutritional requirements for recovery growth in vitro.
  • monitoring a long-term storage experiment designed to reveal the potential interactions between humidity and temperature for a range of species with seeds differing in provenance, mass and oil content.
  • considering the mechanistic basis for underperformance of species under dry cold storage conditions, eg international gene bank standards, in relation to limitations of the seed viability equation, complex relaxation properties of seed glasses and the potential interfering effect of seed lipid crystallisation.
  • investigating how seeds cope in situ with winter conditions and how stored pollen can be used to enable seed production in threatened plants, thus providing a means of integrating ex situ and in situ conservation approaches.

Our expert knowledge of seed storage and biotechnology is shared with international partners and citizen scientists (amateur growers), particularly to encourage seed conservation of rare species held in living collections.

Recent Publications

*denotes Kew staff

  • Chen*, H.Y., Pritchard*, H.W., Seal*, C.E., Nadarajan*, J., Li, W.Q., Yang, S.X. & Kranner*, I. (2012). Post desiccation germination of mature seeds of tea (Camellia sinensis L.) can be enhanced by pro-oxidant treatment, but partial desiccation tolerance does not ensure survival at -20ºC. Plant Science 184: 36-44.
  • Hosomi, S.T., Custodio, C.C., Seaton*, P.T., Marks*, T.R. & Machado-Neto, N.B. (2012). Improved assessment of viability and germination of Cattleya (Orchidaceae) seeds following storage. In Vitro Cellular & Developmental Biology-Plant 48: 127-136.
  • Malik, S.K., Chaudhury, R. & Pritchard, H.W. (2012). Long-term, large scale banking of Citrus species: comparison between cryopreservation and other seed banking temperatures. CryoLetters 33:453-464.
  • Popova, E.V., Kim, D.H., Han, S.H., Pritchard*, H.W. & Lee, J.C. (2012). Narrowing of the critical hydration window for cryopreservation of Salix caprea seeds following ageing and a reduction in vigour. CryoLetters 33: 220-231.
  • Xia, K., Daws*, M.I., Stuppy*, W., Zhou, Z.K. & Pritchard*, H.W. (2012). Rates of water loss and uptake in recalcitrant fruits of Quercus species are determined by pericarp anatomy. PLoS One 7(10), e47368.