Aroid Cryopreservation

Development and refinement of cryopreservation protocols for the long-term conservation of aroids, namely Alocasia, Colocasia, Cyrtosperma and Xanthosoma species.

Long-term storage, cryopreservation (liquid nitrogen, -196oC) is employed at which temperature, all cellular divisions and metabolic processes are stopped. The plant material can thus be stored without alteration or modification for an unlimited period of time in a small volume, protected from contamination, requiring very little maintenance. Cryopreservation currently offers the only safe and cost-effective option for the long-term conservation of genetic resources of vegetatively propagated species and also has shown to improve the frequency of virus elimination in crops as bananas (Musa spp.) (Helliot et al. 2002). Cryopreservation protocols have been developed for numerous species from temperate and tropical origin. The development of the droplet freezing method by Schäfer-Menuhr et al. (1997) for the conservation of potato has proven to give good regenerations of other crops as yams (Leunufna and Keller 2003), banana (Panis et al. 2003) and taro (Colocasia esculenta var. esculenta) (Sant et al. 2008).

The current project aims at developing/refining cryopreservation techniques for taro and other edible aroids. Once these techniques are available and fully operational, their application in the SPC CePaCT, and other relevant genebanks will ensure safe and efficient long-term storage, thereby contributing to the improved conservation of these crops of global importance for food security and nutritional security.

Recently, preliminary experiments have been carried out on Cyrtosperma merkusii (swamp taro).  To date two treatments have been tested on the exposure time to Plant Vitrification Solution 2 (PVS2); 10 and 12 minutes respectively. Results indicate that the best exposure time was 12 minutes where an emergence  of shoots was apparent, whereas for the 10min exposure time the  shoot tips were observed to be bleached. As these are preliminary trials, further experiments have to be established before any conclusions can be made.