Germplasm health testing validation data for sweet potato

Contributors to this section: CIP, Lima, Peru (Carols Chuquillanqui, Segundo Fuentes, Ivan Manrique, Giovanna Muller, Willmer Pérez, Reinhard Simon, David Tay, Liliam Gutarra); CIP, Nairobi, Kenya (Ian Barker); FERA, UK (Derek Tomlinson, Julian Smith, David Galsworthy, James Woodhall).

Sweetpotato germplasm health testing

Protocol for health testing of sweetpotato material has been modified to increase the range of viruses tested and to reduce the risk of any disease escape. The primary diagnostic tool is indexing by Ipomoea setosa. In-vitro diagnosis is carried out by NCM-ELISA for 10 viruses: SPFMV, SPMMV, SPVG, SPLV, SPMSV, SPCFV, C-6, SPCSV, SPCaLV, CMV. Some grafted Ipomoea setosa show symptoms caused by virus infection but they do not react to any of the above antisera. Symptoms observed in I. setosa resemble to those caused by begomoviruses (confirmed by PCR), potyviruses, and caulimoviruses.

During 2006-2010 (August), a total of 2,348 sweetpotato accessions have been virus-tested.

A validation process is being carried out for the methods applied to determine the health status of the material.

Click here to download the full publication on sweetpotato germplasm health testing (1.8 MB).

General principles underpinning safe transfer of tissue cultured clonal germplasm

Contributors to this section: CIP, Lima, Peru (Carols Chuquillanqui, Segundo Fuentes, Ivan Manrique, Giovanna Muller, Willmer Pérez, Reinhard Simon, David Tay); CIP, Nairobi, Kenya (Ian Barker); FERA, UK (Derek Tomlinson, Julian Smith, David Galsworthy, James Woodhall).

Introduction

Over a ten year period beginning in the late 1980s, FAO/IBPGR commissioned a number of Technical Guidelines intended for the safe movement of small quantities of crop plant germplasm between countries for the use in breeding, research and germplasm conservation and evaluation programmes. Occasionally, in response to pest and disease epidemics, larger quantities of disease resistant/tolerant germplasm were transferred for incorporation into rapid multiplication schemes to replace crop plants lost to disease. An example of this has been the shipment of Cassava mosaic disease resistant cassava clones from the International Institute of Tropical Agriculture (IITA) for incorporation into the multiplication programmes of a number of African countries to replace cassava destroyed in the 1990’s Cassava mosaic disease pandemic.

Few of the guidelines have been revised since their publication and information has become dated, particularly in relation to diagnostics. Furthermore, it is accepted, given the now almost universal access to internet resources, that a new approach involving a web-based database will be more appropriate than the existing guides. Such a database can be more readily updated by designated crop plant and pest and disease specialists, resulting in a more robust document that will remain relevant. There is thus a need to update the guides.

These changes withstanding, the principles outlined by Jeffries’ (1998) in the technical guide for the safe movement of potato germplasm still apply and require only minor modifications before applying to the movement of other germplasm.  

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General and technical recommendations

General recommendations

• These guidelines apply to tissue cultured clonally cultivated species (Solanum, Manihot, Musa, Ipomoea and Dioscorea) and are intended for use by research workers and specialised institutions engaged in plant breeding, germplasm conservation and evaluation.
• International movement of germplasm must comply with the regulatory requirements of the countries involved. Prospecting activities for conservation must be based on prior consultation with the relevant plant protection organisations (PPOs) and a knowledge of organisms in the relevant countries.
• Information exchange between exporter and importer must be sufficiently transparent for a full evaluation of the pest risk. Wherever possible, material should be selected from the least risk source, e.g. an institution which maintains pathogen-tested germplasm. Indexing procedures and precautions taken to prevent infection and contamination of the germplasm after testing should be documented, e.g. in a 'Germplasm Health Statement'.
• Growing of untested germplasm outside effective containment and/or isolation is not recommended. Collecting and conservation activities must be preceded by establishing the nearest point where the material can be placed in quarantine containment.
• Movement of pathogen-tested stem cuttings is not recommended because of the risk of the material becoming infected after testing.
• Pathogen-tested material should be derived from tested parents and maintained under conditions designed to prevent infection and contamination. Absence of pathogens should be established by applying appropriate indexing procedures and these should be verified as appropriate.
• Risks can be reduced further by post-entry quarantine containment (e.g. insect-proof houses, out-of-season cultivation, growing in an isolated area with no links to the material involved) and quarantine testing. Post-entry quarantine containment/testing is a requirement in many countries. Some countries, however, will accept the testing done by specified countries as being equivalent to their own and accept material without the need for post-entry quarantine containment/testing. Untested or infected material must be managed so as not to be a risk to tested material.
• The volume of consignments should not be larger than is necessary to preserve the genetic usefulness of the germplasm. In the case of vegetative material and seeds, quantities recommended are 1-10 plants and 20-200 seeds respectively. Increasing quantities may lead to resource problems in containment and testing.
• Some PPOs stipulate that each unit (in vitro plantlet, seed/seedling and pollen-derived plant) of germplasm is tested individually for quarantine pests, whereas other authorities allow, particularly for seed, test results derived from bulked samples representative of the consigned germplasm.
• Normally in vitro material contaminated with saprophytic organisms should be destroyed. However, where the material is rare or valuable, such contamination may be dealt with by appropriate treatments. Antibiotics and fungicides must not be added to the medium for shipment.
   

Technical recommendations

These recommendations are adapted from Jeffries, 1998. A number of International Standards for Phytosanitary Measures (ISPM) apply to he transit of clonal germplasm in international trade. Information by Seabrook and Coleman (1988) on the shipping of in-vitro material is still pertinent.

• Technical recommendations for the exporting country
• Technical recommendations for the importing country

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References and further reading

Bradbury JF. 1986. Guide to Plant Pathogenic Bacteria. CAB International.

CABI. http://www.cabi.org/. Date accessed 20 April 2010.

CABI Arthropod Name Index on CD-Rom. 1996. Gives information on synonyms and links to old Review of Applied Entomology volumes (including pre-1973).

CABI CPC. CABI Crop Protection Compendium. [online] Available from URL: http://www.cabi.org/compendia/cpc/ Date accessed 20 April 2010.

Carroll LE, White IM, Freidberg A, Norrbom AL, Dallwitz MJ, Thompson FC. 2004. Pest Fruit Flies of the World: Larvae. [online] Available from URL: http://delta-intkey.com/ffl/www/_wintro.htm Date accessed 20 April 2010.

DPV Web. Descriptions of plant viruses. EPPO PQR, 2005. EPPO Plant Quarantine Information Retrieval System, Version 4.6, 2007 1 Rue le Notre, 75016, Paris, France [online] Available from URL: http://www.dpvweb.net/ Date accessed 20 April 2010.

Esser RP. 1991. A computer ready check list of the genera and species of phytoparasitic nematodes including a list of mnemonically coded subject categories. Florida Dept. of Agriculture and Consumer services, 185 pp.

Evans K, Trudgill DL, Webster JM, editors. 1993. Plant parasitic nematodes in temperate agriculture. CAB International, Wallingford, 648 pp.

Farr DF, Rossman AY, Palm ME, McCray EB. undated. Fungal Databases, Systematic Botany & Mycology Laboratory, ARS, USDA. [online] AVailable from URL: http://nt.ars-grin.gov/fungaldatabases/ Date accessed 24 July 2007.

Firrao G, Andersen M, Bertaccini A, Boudon E, Bove JM, Daire X, Davis RE, Fletcher J, Garnier M, Gibb KS, Gundersen-Rindal DE, Harrison N, Hiruki C, Kirkpatrick BC, Jones P, Kuske CR, Lee IM, Liefting L, Marcone C, Namba S, Schneider B, Sears BB, Seemuller E, Smart CD, Streten C, Wang K. 2004. 'Candidatus Phytoplasma', a taxon for the wall-less, non-helical prokaryotes that colonize plant phloem and insects. International Journal of Systematic and Evolutionary Microbiology 54, 1243-1255.

Hill DS. 1983. Agricultural Insect Pests of the Tropics and their control, 2nd Edition. Cambridge University Press, London, 746 pp.

Hill DS. 1987. Agricultural Insect Pests of Temperate Regions and their control. Cambridge University Press, London, 660 pp.

ICTVdb. The Universal Virus Database of the International Committee on Taxonomy of Viruses. Colombia University. [online] Available from URL: www.ncbi.nlm.nih.gov/ICTVdb/ Date accessed 20 April 2010.

Index Fungorum Partnership. 2004. Index fungorum. [online] Available from URL: http://www.indexfungorum.org/NAMES/NAMES.asp Date accessed 20 April 2010.

Jeffries CJ. 1998. Potato: FAO/IPGRI Technical guidelines for the safe movement of potato germplasm. International Plant Genetic Resources Institute. Rome, Italy. Available here (1.9 MB)

Jeppson LR, Keiffer HH, Baker EW. 1975. Mites Injurious to Economic Plants, University of California Press, Berkley, 614 pp.

Kirk PM, Cannon PF, Stalpers JA, editors. 2008. Dictionary of the Fungi, 10th Edition. CABI, UK.

Luc M, Sikora RA, Bridge J, editors. 2005. Plant Parasitic Nematodes in Subtropical and tropical Agriculture. CAB International, Wallingford, 871 pp.

National History Museum. 2010. The Global Lepidoptera Names Index. [online] Available from URL: http://www.nhm.ac.uk/research-curation/projects/lepindex/ Date accessed 20 April 2010.

ProMed Mail [online]. Available from URL: http://www.promedmail.org/ Date accessed 20 April 2010.

ScaleNet. All about scale insects. http://www.sel.barc.usda.gov/scalenet/query.htm Date accessed 20 April 2010.

Smith IM, Dunez J, Lelliott RA, Phillips DH, Archer SA. 1988. European Handbook of Plant Diseases. Blackwell Scientific Publications, Oxford.

The American Phytopathological Society. Plant Disease Notes: An International Journal of Applied Plant Pathology. ASPnet [online] Available from URL: http://www.apsnet.org/pd/ Date accessed 20 April 2010.

Waller JM. 2002. Regional and country lists of plant diseases pp 287-308. In: Waller JM, Lenne JM,  Waller SJ, editors. Plant Pathologist’s Pocketbook. CAB International 2002, 516 pp.

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Contributors to this section: CIP, Nairobi, Kenya (Ian Barker); CIP, Lima, Peru (Carols Chuquillanqui, Segundo Fuentes, Ivan Manrique, Giovanna Muller, Wilmer Pérez, Reinhard Simon, David Tay); FERA, UK (Derek Tomlinson, Julian Smith, David Galsworthy, James Woodhall).
 

Pest list information

Contributors to this section: CIP, Lima, Peru (Carols Chuquillanqui, Segundo Fuentes, Ivan Manrique, Giovanna Muller, Willmer Pérez, Reinhard Simon, David Tay); CIP, Nairobi, Kenya (Ian Barker); FERA, UK (Derek Tomlinson, Julian Smith, David Galsworthy, James Woodhall).
 

Pest lists

Banana viruses list

Cassava disease list

Potato disease list

Sweetpotato disease list

Yam viruses list

Quality systems

Contributors to this section: CIP, Lima, Peru (Carols Chuquillanqui, Segundo Fuentes, Ivan Manrique, Giovanna Muller, Willmer Pérez, Reinhard Simon, David Tay); CIP, Nairobi, Kenya (Ian Barker); FERA, UK (Derek Tomlinson, Julian Smith, David Galsworthy, James Woodhall).

Quality systems and validation for the safe transfer of clonal germplasm

The acquisition, conservation and distribution of germplasm and planting material is a core function of many agricultural organisations and serves to underpin breeding programs worldwide. Crops are infected by a number of viral, viroid, phytoplasma and bacterial diseases, which can be transmitted through exchange of germplasm and planting material. The aim should be to only distribute material of the sufficiently high health status to prevent the possible movement of pathogens around the world and the consequent damage to food security, livelihoods and economies. Compliance with all National and International phytosanitary treaties, regulations and requirements relating to both phytosanitation and also the Convention on Biological Diversity (CBD) is also a key requirement of this aim.
 

Click here to download the complete quality systems and validation document (4 MB).

Click here to download the validation template (1 MB).