Micropropagation and Cryopreservation of Hawaiian Pritchardia

The Hawaiian Rare Plant Program (HRPP) Micropropagation Laboratory serves as an ex-situ germplasm repository for Hawaii’s rarest plant species. Introduction of the coconut rhinoceros beetle (Oryctes rhinoceros) to Hawaii is a major threat to wild populations of the twenty-three endemic Pritchardia species, many of which are already endangered. Using tissue culture, the HRPP Micropropagation Lab has developed techniques to produce propagules of Pritchardia rapidly and reliably via embryo rescue. Establishment of Pritchardia embryos into tissue culture at the HRPP has a very high success rate and can produce propagules ready to come out of the lab after three months of growth. The high success rate is largely due to the elimination of the need for direct sterilization of the embryos prior to establishment in tissue culture. Many of the propagules produced over the past year will be used to establish ex-situ collections of Pritchardia outside of Hawaii at the San Diego Zoo and Botanical Garden and at other sites. Pritchardia fruits are not storable by conventional seed banking methods. Preliminary research into the cryopreservation of Pritchardia embryos is currently underway at the HRPP Micropropagation Lab. Embryo desiccation by airflow and fast freezing methods show promising results for the long-term preservation of Pritchardia species. Questions remain regarding differences in cryopreservation treatment and post-thaw recovery for embryos at different maturity levels and between species.