Safe Distribution of Plant Material

Thursday, 06 September 2012 15:39

Apart from its core function of sustainable conservation of plant genetic resources, the Centre for Pacific Crops and Trees (CePaCT) of SPC’s Land Resources Division (LRD) has been actively involved in distributing virus-tested material of selected crops and accessions for evaluation by Pacific countries. CePaCT is the central hub for regional and global exchange of plant material, which is made possible under the Standard Material Transfer Agreement provided in the International Treaty on Plant Genetic Resources for Food and Agriculture.

The crops being distributed consist mainly of accessions obtained from CePaCT’s climate-ready collection, from which accessions are selected, based on demonstrated tolerant traits to drought, salt and water logging in Pacific and Asian countries.  Nutrient-rich crops, such as those that are high in carotenoids, are also being distributed.  Some are resistant to disease such as black leaf streak of bananas and leaf blight in taro. These crops were sourced from within the region and from international agricultural research institutes in Peru, Columbia, Nigeria, Australia and Belgium.

The movement of any germplasm is carefully screened to ensure plants are safe and free of any possible pathogens, especially viruses.

Mr Amit Sukal, the Virus Diagnostic Officer at CePaCT explains, ‘Some viruses can cause great devastation to crops and crop yields, but these risks can be eliminated by ensuring that the plant material we exchange is tested, using the latest technology available for virus detection.’

Mr Sukal explained that the new state of the art virus indexing facility in CePaCT was specifically built for this purpose. This highly specialised laboratory has the latest equipment, which allows for effective screening of crop varieties prior to distribution. Only clean or virus-free crop varieties that have gone through several stages of virus testing are declared safe for distribution.

CePaCT uses internationally recognised and approved protocols for virus testing. Some of these employ molecular, serological and symptomatological technologies. The virus testing process takes up to six months for uninfected varieties, but may take longer than a year for an infected variety, as it will have to go through the cleaning process. Once a variety has been tested negative to known viruses it is then put up for distribution.

Staff sampling leaves in the PEQ facility for virus testing

Infected material can be cleaned using meristem extraction, chemotherapy, thermotherapy and electrotherapy. These techniques have been widely used to remove viruses, and research is under way at CePaCT to see which method can be adopted for routine use.  No plant material leaves the Centre before it is pathogen-tested. It is all about safety.

CePaCT carries out testing for all known viruses of taro, Alocasia, Xanthosoma, swamp taro, banana, sweet potato and yam. This is very important for the Pacific as the countries do not have the resources to do the virus testing themselves. To facilitate requests for virus testing of samples, CePaCT imports treated vegetative material, using protocols approved by the Biosecurity Authority of Fiji.

The growing of a plant in a sterile artificial nutrient medium in a culture vessel under sterile conditions, often called tissue culture, is recognised as a safe method for the exchange of plant genetic resources. The aseptic process used in the preparation of plant material during the tissue culture process eliminates pathogens that you would normally risk distributing when you are dealing with plant material exchange.

The establishment of a virus testing facility means that the Centre now has the capability to carry out these tests, which used to be carried out in developed countries such as Australia. The efficiency of the Centre’s work has improved, and so has the number of crops going on distribution.

‘Besides this, we made huge savings, because testing one sample in Australia used to cost over USD 300,’ concluded Mr Sukal.

Valerie Saena Tuia, Officer in Charge of Genetic Resources added, ‘Building the capacity of CePaCT and regional staff to use the latest virus diagnostic technology competently is very important.’

CePaCT’s virus laboratory has passed international validation programmes to ensure that CePaCT stays in par with internationally approved protocols followed by other international testing facilities. The Centre is also recognised by the Australian Quarantine Inspection Service as one of the virus indexing facilities for Pacific crops, especially for carrying out tests on known viruses of taro and other aroids.

The virus indexing capacity building of regional staff, including CePaCT staff, started initially as a component of the AusAID Taro Genetic Resources: Conservation and Utilisation project that involved providing capacity building and technology transfer for practitioners in the Pacific region. Global networking of SPC with other recognised institutes through different projects on virus work has further built the capacity of staff to do virus indexing.

The virus indexing facility equipment and consumables were mainly funded by donors, with major funding provided by the AusAID International Climate Change Adaptation Initiative project and some critical equipment donated by GIZ

‘The funding assistance has contributed greatly in supporting the capacity of the Centre to do more virus-indexing work on Pacific crops,’ said Valerie Saena Tuia.

For further information please contact SPC Amit Sukal ( AmitS@spc.int ) or Valerie Tuia ( ValerieS@spc.int ) on + (679-3370733)