Coconut Ecomuseum: Coconut research activities in South Korea

In 2009 (30 November - 2 December), Dr R. Bourdeix took part in an expert consultation in Suwon, South Korea to assess the developments of coconut in vitro culture and cryopreservation.

This meeting was part of the project "Alternative approaches for cryopreservation of coconut, sweet potato and selected indigenous crops in the Asia Pacific (AP) region". The purpose of this research regarding coconut was:

To optimise the coconut cryopreservation protocol for large-scale implementation of coconut germplasm conservation
To upscale the developed protocol for application in the conservation of coconut
To develop the capacity of national and international coconut genebanks to use cryopreservation in conserving coconut

Because of its large, recalcitrant seed that exhibits no dormancy, coconut diversity is conserved in field genebanks, which until recently has been the only practical method for coconut ex situ conservation. They however require a large area and substantial resources to maintain, and are subject to many risks such as exposure to pests, diseases, abiotic stresses and natural and man-made calamities. Many countries also lack the capacity and financial resources to maintain their collections.

Currently, coconut embryo transfer offers a feasible means of safely sharing and conserving coconut germplasm. This includes ensuring optimal embryo (or plug) selection and transfer, according to strictly observed protocols.

As another potential means of ensuring long-term conservation, accessions can now also be cryo-preserved, that is frozen to the temperature of liquid nitrogen (-196°C). Cryopreservation arrests both the growth of plant cells and all processes of biological deterioration, so that the material can be preserved for extended periods and resuscitated into fully viable plants. The one-off cost of cryo-preserving accessions is expected to pay off against the recurrent costs of in vitro or in field maintenance over a number of years.

A robust cryopreservation protocol needed to be developed and validated. The factors governing protocol success needed to be carefully identified and controlled to obtain favourable results. Recognizing this need, Korea RDA and Bioversity International, as part of their partnership to enhance the sustainable use and conservation of genetic resources in the Asia Pacific region signed a new Memorandum of Understanding (MOU) in 2009 that included an Rand D partnership for coconut cryopreservation. Following the MOU, the International Coconut Genetic Resources Network (COGENT) proposed a partnership with RDA for creating a global coconut cryobank to provide a safety duplicate of the coconut virtual collection. An expert consultation was also organised in Suwon in 2009 to assess the developments of coconut in vitro culture and cryopreservation.

Studies have indicated that mature coconut embryos are safest for their cryopreservation. The project aimed to optimise existing protocols and make these more efficient for cryopreservation. Among the cryopreservation techniques that have been widely tested, the proposed project emphasized on the use of vacuum assisted procedures involving physical and chemical dehydration and the droplet-vitrification method of coconut embryos. A systematic study using these alternative approaches is required to provide a solid basis for understanding the various factors leading to the success in long term storage of materials under cryogenic temperatures.

Reference

Cueto, C., Rivera, R. L., Kim, H. H., Kong, H. J., Baek, H. J., Sebastian, L., & Park, H. J. (2014). Development of cryopreservation protocols for cryobanks of coconut zygotic embryos. Acta Horticulturae, (1039), 297-302.