SUBJECT

This directive describes the requirements for the production, maintenance, multiplication and certification of Nuclear Stock class seed potatoes under Canada's national seed potato certification program.

It sets out the technical standards for the initiation, maintenance and multiplication of in vitro plantlets, micro-tubers and mini-tubers, including standards for pathogen testing, varietal purity, physical facilities and documentation.

This directive has been updated to reflect current practices in the production of nuclear stock seed potatoes, and to reformat the directive to make it easier for CFIA staff and industry to follow the provisions of the directive and to ensure that its requirements are adhered to.

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Table of Contents

• Review
• Endorsement
• Amendment Record
• Distribution List
• Introduction
• Scope
• Definitions, Abbreviations and Acronyms
• 1.0 General Requirements
  • 1.1 Legislative Authority
  • 1.2 Fees
• 2.0 Specific Requirements
  • 2.1 General Production Requirements
  • 2.2 Aseptic Facility Requirements
  • 2.3 Initiation in an Aseptic Facility
  • 2.4 Multiplication in an Aseptic Facility
  • 2.5 Multiplication in a Protected Environment
  • 2.6 Certification
  • 2.7 Transfer
• 3.0 Appendices
• Appendix 1: Summary Table of General Requirements for Certified Nuclear Stock Seed Potato Production

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Review

This directive will be reviewed every three years unless otherwise needed. The next review date for this directive is October 29, 2011. The contact for this directive is Joanne Rousson. For further information or clarification, please contact the Canadian Food Inspection Agency (CFIA).

Endorsement

Approved by:

Chief Plant Health Officer

Amendment Record

Amendments to this directive will be dated and distributed as outlined in the distribution below.

Distribution List

1. Directive mail list (Regions, PHRA, USDA)
2. Provincial Government, Industry (via Regions)
3. National Industry Organizations (Canadian Horticulture Council)
4. Internet - CFIA website

Introduction

Canada's seed potato certification program is based on the continuous input of Nuclear Stock class seed potatoes, i.e., potatoes that have been produced from pathogen-tested tissue culture plantlets under protected environment conditions. Nuclear Stock class seed potatoes, when planted in the field for the first time, will produce Pre-Elite class seed, provided the crop remains visibly free of disease symptoms, maintains varietal purity and meets the requirements of the Seeds Regulations Part II, as determined by the appropriate number of field inspections and laboratory analysis.

In subsequent years of multiplication, the certification class of the progeny seed is lowered to Elite 1, Elite 2, Elite 3, Elite 4, Foundation and Certified class, with each class having to meet standards specified by the Seeds Regulations Part II for varietal purity and disease tolerances. All seed classes, except Certified, may be used for further seed production. Certified class seed can only be used to produce ware potatoes. The regulated and mandatory application of these principles for seed potato production provides for a "limited generation" or "flush-through" certification system.

All seed potatoes produced in Canada are inspected in accordance with national inspection standards and, when required, representative samples of lots are analysed in CFIA-approved laboratories, in order to determine compliance with requirements and tolerances pursuant to the Seeds Regulations, Part II.

Scope

This directive is intended for use by CFIA staff and Canadian producers of Nuclear Stock class seed potatoes.

This directive supercedes D-97-08 (2^nd Revision)

Definitions, Abbreviations and Acronyms

Definitions for terms used in the present document can be found in the Plant Health Glossary of Terms.

1.0 General Requirements

1.1 Legislative Authority

Seeds Act (R.S. 1985, c. S-8)
Seeds Regulations (C.R.C., c. 1400), Sections 45-62
Canadian Food Inspection Agency Fees Notice, Canada Gazette: Part I (as amended from time to time)

1.2 Fees

The CFIA is charging fees in accordance with the Canadian Food Inspection Agency Fees Notice. Anyone requiring information regarding fees may contact any local CFIA office or visit our Fees Notice Web Site.

2.0 Specific Requirements

Three phases are recognized in the production of Nuclear Stock class seed potatoes:

Initiation: where pathogen-tested potato propagules are established in an aseptic facility through in vitro micro-propagation (i.e., tissue culture).

Maintenance: where pathogen-tested potato propagules are maintained in an aseptic facility.

Multiplication: where pathogen-tested potato propagules are multiplied in an aseptic facility and/or in a protected environment (e.g., greenhouse, screenhouse, growth chamber, etc.)

2.1 General Production Requirements

The following applies to all Nuclear Stock propagative material.

2.1.1 With the exception of Maintenance, the local CFIA office must receive a complete "Application for Seed Potato Crop Inspection - Grower's Declaration" (CFIA/ACIA 1317), pursuant to the Seeds Regulations Part II. If the farm unit also produces Nuclear Stock class seed potatoes in a protected environment, and/or field grown seed potatoes of other classes, it is recommended that the lots being initiated or otherwise produced in the aseptic facility be listed on a separate page of the submitted application, clearly marked to identify the method of production being utilised.

Note: A grower submitting separate applications for field-grown crops and crops produced in a protected and/or aseptic environment with the intention of operating them as separate farm units (i.e., with different grower numbers) is expected to pay the applicable fees for each application.

2.1.2 A CFIA inspector must inspect all areas within a facility involved in the propagation or initiation of the Nuclear Stock class seed potatoes at least once during active production.

2.1.3 The material being propagated must be of a known varietal/clonal identity and must be duly documented with respect to its origin, date received, multiplication and distribution.

Note: Provision of documentation in support of the identity of a particular variety or clone is the responsibility of the facility, not the CFIA.

2.1.4 A CFIA inspector must issue a Growing Crop Certificate (CFIA/ACIA 1318) for the material determined to meet the requirements of the Nuclear Stock class, pursuant to the Seeds Regulations Part II before the material is transferred to a new owner.

2.1.5 The facility must maintain an information system which documents the following information for each variety/clone:

• variety/clone identification;
  • Note: Each facility may establish its own facility coding techniques for the establishment, maintenance and multiplication of variety/clone;
• date of acquisition and most recent date of maintenance or multiplication of each variety/clone;
• quantity obtained for each variety/clone;
• origin of propagative material, including nuclear stock certificate (if applicable);
• variety/clone protection status;
• the most recent date that samples of each lot were submitted for pathogen tests to a laboratory approved by the CFIA;
• testing results from a laboratory approved by the CFIA;
• actions carried out under the management program for sanitation, insect and disease monitoring, and prevention including removal of any varieties/clones;
• CFIA-issued certification number and documentation (where applicable);
• propagation schedules;
• Nuclear Stock production and distribution data.

The information system, and its associated documentation, must be made available, if requested by a CFIA inspector, for review and audit by the CFIA.

2.1.6 Except for micro-tuber production (where valid disease testing results are required prior to the initiation of the micro-tuber production cycle), each crop under production must have valid disease testing results at all times during the multiplication process. Tests must be carried out on a minimum of two plantlets for each variety/clone. They must be carried out by a laboratory approved by the CFIA and are valid for a period of twelve months commencing on the date that the sample was submitted for testing to the approved laboratory. This date should be included on the official laboratory testing report. Each crop must have been found not to be infected with any of the following organisms:

• Viruses: PVA, PVS, PVM, PVY, PVX, and PLRV.
• Viroid: PSTVd
• Bacteria: C. m. sepedonicus, the causal pathogen for bacterial ring rot (BRR).

2.2 Aseptic Facility Requirements

The following applies to Nuclear Stock class seed potatoes in an aseptic facility.

2.2.1 The multiplication or initiating facility must use recognized aseptic initiation and propagation procedures (i.e., follows procedures and uses equipment which will maintain sterile conditions). Each facility must have a propagation procedure manual for this purpose, for reference by staff as necessary.

2.2.2 If the CFIA confirms the presence of PSTVd or C. m. sepedonicus, in aseptic culture production, all aseptic culture progeny production of the affected variety/clone must be removed from the facility and destroyed.

2.2.3 If the CFIA confirms the presence of C. m. sepedonicus, in other field grown crops under the same farm unit, all field grown crops in that farm unit will have certification revoked. However, an inspector for CFIA may determine, based on verification of aseptic techniques and the absence of contact with field grown crops, that this disease did not affect the Nuclear Stock production and it retains its certification status.

2.2.4 Any variety/clone that tests positive for any other pathogen (other than the ones listed in section 2.1.6), any propagative material or containers used in the propagative process showing symptoms or signs of any bacterial or fungal infection or other presence of such organisms, must be removed from the facility immediately and be sterilized or destroyed.

2.3 Initiation in an Aseptic Facility

Any potato material (i.e., any potato plant part, including stems and tubers) is acceptable for the initiation of and production as Nuclear Stock class seed potatoes, providing that the following requirements have been met.

2.3.1 In addition to the testing outlined in section 2.1.6, a sample of at least two plantlets per variety/clone being initiated must be tested in a laboratory approved by the CFIA and found not to be infected with Potato Latent Virus (PotLV) and Potato Mop-Top virus (PMTV).

2.3.2 If the CFIA confirms the presence of C. m. sepedonicus, in a variety/clone, all other aseptic clonal production for the affected facility will be subject to re-testing to verify freedom from C. m. sepedonicus. The level of testing will be a minimum of 2 plantlets per variety/clone.

2.4 Multiplication in an Aseptic Facility

The following applies to the multiplication of Nuclear Stock class seed potatoes in an aseptic facility.

2.4.1 If the CFIA confirms the presence of C. m. sepedonicus, in a variety/clone, all other aseptic clonal production for the affected facility will be subject to re-testing to verify freedom from C. m. sepedonicus. The level of testing will be 1% or a minimum of 5 plantlets to a maximum of 50 plantlets per clone.

2.5 Multiplication in a Protected Environment

The following applies to the multiplication of Nuclear Stock class seed potatoes in a protected environment.

2.5.1 The facility must be inspected by a CFIA inspector at least once during the growing cycle. Depending on the condition or appearance of the crop, the inspector may take leaf samples for laboratory testing to be carried out by the CFIA to determine if the crop is free of regulated pathogens (section 2.5.11) or to confirm varietal purity. This inspection should be recorded using a Nuclear Stock Protected Environment Inspection Report (CFIA/ACIA 5293).

2.5.2 The protected environment must be "aphid-proof" and be equipped as follows:

• a double-door entrance in which the doors form an aphid-proof closure;
• provision for footwear disinfection prior to entering the protected environment (the disinfectant utilized must be registered for agricultural disinfection purposes as registered with the Pest Management Regulatory Agency and be changed at intervals as recommended on the manufacturer's label);
• aphid-proof ventilation screening on all intakes and exhaust openings (including louvred fan exhausts). All aphid screening used must have a minimum of 12 meshes per centimetre (30-32 meshes per inch);
• there must be no holes in the structure that would allow aphids to enter the protected environment.

2.5.3 The grower must notify the CFIA prior to the proposed date of planting in order to allow sufficient time for a pre-planting inspection to be scheduled, if deemed necessary. Approximately two weeks advance notice may be sufficient, depending on the demands on the local CFIA office. At the inspector's discretion, the protected environment may be required to be inspected and approved by a CFIA inspector before planting can proceed. This pre-planting inspection, and approval to plant, should be recorded using a Nuclear Stock Protected Environment Inspection Report (CFIA/ACIA 5293). If the protected environment does not meet program requirements, a Notification of Non-Compliance of Nuclear Stock Production Facility and Requirement for Corrective Action (CFIA/ACIA 5294) should be completed and a copy provided to the grower as soon as possible.

2.5.4 The facility must be cleaned and disinfected, and must be free from all potato and solanaceous plant debris prior to planting.

2.5.5 No field-produced seed potatoes (including pathogen tested clonal selections), non-seed potatoes, nor any other Solanaceous, Pelargonium species or other host plants of Ralstonia solanacearum Race 3, Biovar 2 can be grown in the same protected environment facility. In addition, any quarantine pathogen for seed potatoes identified in the air, water, soil or environment associated with a Nuclear Stock production facility will result in decertification or the refusal by the CFIA to grant certification as Nuclear Stock of all seed potato crops grown in that production facility.

2.5.6 The producer must adopt a management program that includes effective sanitation practices and effective insect and disease monitoring and prevention procedures (i.e. use of yellow sticky traps for aphid monitoring, adoption of integrated pest management practices, records of any pests or diseases observed and corrective actions taken, etc.)

2.5.7 Nuclear Stock class propagative material must be planted in soil-free medium which has not been recycled.

2.5.8 If ground beds are used, the underlying soil must be separated by a new or clean, disinfected physical barrier from the growing medium (e.g., separated by landscape cloth). If containers are used, they must be new, or cleaned and disinfected.

2.5.9 The crop must be grown from certified Nuclear Stock class seed potatoes which were produced in an aseptic facility, or from first generation Nuclear Stock class mini-tubers produced in the grower's own protected environment facility, or from stem cuttings produced in the grower's own protected environment facility.

2.5.10 Varieties/clones must be separated by physical barriers which will maintain varietal purity.

2.5.11 Each crop under production must have valid disease testing results at the time of planting in a protected environment, unless planting first generation mini-tubers (section 2.5.12).

2.5.12 If first generation mini-tubers are used to produce a second generation, a CFIA inspector shall not certify the second generation unless the first generation or the second generation has been tested by a laboratory approved by the CFIA and found to be free from the pathogens listed in section 2.1.6.

2.5.13 When additional pathogen testing is required on a crop producing mini-tubers, samples should be collected at budding/flowering time (approximately 40 -70 days after planting) on a representative sample consisting of 1% of the plants/tubers with a minimum of 5 and a maximum of 50 plants/tubers sampled per lot. All samples taken for required pathogen testing must be collected under the supervision of a CFIA inspector.

2.5.14 If the CFIA confirms the presence of C. m. sepedonicus, in a protected environment facility, all production of the affected facility must be destroyed. However, a CFIA inspector may determine, based on the definition of farm unit and verification of sanitation techniques utilised in the protected environment and separation with field grown production, that this disease was not in contact with field-grown production and it may retain its certification status.

2.5.15 If the CFIA confirms the presence of C. m. sepedonicus, in other field grown potatoes identified under the same application and definition of farm unit, all field grown seed potato crops will have certification revoked. However, a CFIA inspector may maintain the certification status of the crops grown in the protected environment, based on the definition of farm unit, verification of sanitation techniques and the absence of contact between the field grown crops and the ones grown in the protected environment.

2.5.16 If the CFIA Charlottetown Laboratory confirms the presence of PSTVd, the infected variety/clone will not be eligible for certification. All plant parts from any variety/clone that tests positive for PSTVd must be removed from the facility immediately and be destroyed.

2.5.17 In the event that insect disease vectors (e.g., aphids) are detected by a CFIA inspector on or in the growing crop, including evidence of wingless aphids, nymphs, molting skins, dead and/or parasitized aphids, the grower must provide post-harvest test results to the CFIA. One or two extraneous winged aphid(s) or vector(s) found on sticky traps, or in areas not directly in contact with the crop, does not automatically indicate additional testing requirements, but will alert the inspector and the grower to be vigilant during the crop management and their inspection of the crop, to ensure vector activity is not occurring in the growing crop.

After confirming the evidence of virus vectors in the crop, a representative sample collected under the supervision of a CFIA inspector (consisting of 1% of the harvested tubers with a minimum of 5 and a maximum of 50 tubers sampled per lot), for each variety/clone produced in the protected environment, must be post-harvest virus tested and, provided the results are negative for PVS, PVM, PVA, PVY and PLRV, the crop will be assigned Nuclear Stock class¹. Failure to provide post-harvest test results, if required to do so, will result in assigning Pre-Elite class to all varieties/clones in the protected environment (provided that all other standards of the class have been met as specified in the Seed Regulations, Part II).

2.5.18 If testing performed by a laboratory approved by the CFIA reveals the presence of PVA, PVS, PVM, PVY, PVX, or PLRV, the crop will be assigned the Pre-Elite class (provided that it meets the appropriate standards as specified in the Seed Regulations, Part II), not Nuclear Stock class, and allowed to be grown for the next generation by the owner only.

2.6 Certification

2.6.1 For Nuclear Stock produced in a protected environment, the application must be filed within thirty days after planting the crop(s) in the protected environment. (NOTE: the requirement to notify the local CFIA office in advance of planting stated in section 2.5.3 to allow for a pre-planting facility inspection, if deemed necessary, still applies). Amendments to the application can be made no later than the appropriate inspection time for the crop growing in the protected environment facility. A subsequent inspection may be required for those crops not at 40-70 days maturity. A new application must be filed for crops not planted at the time of inspection (40-70 days).

For facilities under continuous propagation and production, an arrangement with the local inspection office must be determined and formal notification with that office listing new crops growing in the appropriate window for inspection, must be filed, inspected and recorded on the application for seed potato crop inspection (CFIA/ACIA 1317) and entered into the CFIA Multi Commodity Activity Program database (MCAP). Under these provisions, one annual application will suffice.

2.6.2 Certification of each variety/clone will be granted by the CFIA, following official inspections, if all the requirements under section 2.1, 2.2 or 2.4 or 2.5 have been met, and the crop meets all the standards of the Seeds Regulations Part II.

2.7 Transfer

2.7.1 Nuclear Stock class seed potatoes being transferred to a new owner must be accompanied by one of the following certificates supplied by the CFIA prior to the transfer of the stock:

• Nuclear Stock Tags (CFIA/ACIA 5298) are used for mini-tubers of a variety registered in Canada produced in a protected environment and shipped domestically. Tags must be attached to the container of mini-tubers they represent.
• Nuclear Stock Certificates (CFIA/ACIA 4351) are issued for micro-tubers, plantlets and mini-tubers of a registered variety or unregistered variety exported to a foreign country.
• Certificates of Authorization (CFIA/ACIA 4378) are issued for all unregistered varieties shipped domestically.

2.7.2 An application for issuance of either Nuclear Stock Tags or Certificates should be made by the producer using the Application Form for Issuance of Nuclear Stock Tags and Certificates (CFIA/ACIA 5295)

2.7.3 Nuclear Stock class seed potatoes produced in a protected environment and transferred to a new owner cannot be used to further produce Nuclear Stock class seed potatoes.

3.0 Appendices

Appendix 1: Summary Table of General Requirements for the Production of Nuclear Stock Class Seed Potatoes

Footnote:

¹Testing for PotLV and PMTV is performed once only at the initiation phase.

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Appendix 1

Summary Table of General Requirements for the Production of Nuclear Stock Class Seed Potatoes

CRITERIA	INITIATION (aseptic)	MAIN- TENANCE (aseptic)	MULTIPLI- CATION (in an aseptic facility)	MULTIPLI- CATION (in a protected environment)	COMMENTS
An application for certification must be filed with CFIA	Must be filed before the material is transferred to a new owner or transferred into a protected environment or planted in a field.	N/A	Must be filed before the material is transferred to a new owner or transferred into a protected environment or planted in a field.	Must be filed within 30 days after the crop(s) have been planted. See details in section 2.6.1	Use the application for seed potato crop inspection (CFIA/ACIA 1317). It is recommended that a separate page be used to differentiate between each type of production.
Inspection requirements	- At least once during active production. - Recorded on CFIA/ACIA 5292.	N/A	- At least once during the multiplication phase. - Recorded on CFIA/ACIA 5292.	- At least once, at or about budding / flowering time (40-70 days after planting) Plus, an optional pre-planting inspection (see 2.5.3)	If the facility does not meet program requirement, use form CFIA/ACIA 5294 for corrective action.
Recognized aseptic initiation and/or propagation procedures	Each facility must have a propagation procedure manual (2.1.5).	The facility must use recognized aseptic propagation procedures.	Each facility must have a propagation procedure manual (2.2.1).	The protected environment must be "Aphid proof" (2.5.2). The producer must adopt a management program that includes effective sanitation practices
Lab testing requirements: free of virus / viroid / bacteria	Minimum of 2 plantlets per variety. Viruses: PVA, PVS, PVM, PVY, PVX, PLRV, (PotLV, PMTV Viroid: PSTVd Bacteria: BRR A positive test will result in the disposal of that clone and all its progeny	No requirements. Except: Where maintenance takes place in a facility other than the Initiating facility, the material must be certified as Nuclear Stock class seed potatoes prior to maintenance. Note: Maintenance within initiating facility requires separation between Nuclear stock and other material	Minimum of 2 plantlets per variety (valid for one year, must have valid testing results at all times during multiplication process) Viruses: PVA,PVS, PVM, PVY, PVX, PLRV Viroid: PSTVd Bacteria: BRR Except for micro-tuber production where testing results are required prior to initiation of the production cycle.	Must have valid testing results at the time of planting for the following: Viruses: PVA, PVS, PVM, PVY, PVX, PLRV Viroid: PSTVd Bacteria: BRR Except for planting first generation mini-tubers (details in section 2.5.9 and 2.5.12)	For clarification on determining the validity period, the recognized twelve month period will commence on the date that the samples was submitted for testing to the lab (must be in a CFIA accredited laboratory). PMTV and PLRV testing are done at the Initiation phase.
If BRR is detected C. m. sepedonicus (causal agent of bacterial ring rot)	- Destroy all progeny of that clonal line - Retest all other aseptic clonal production in the affected facility. Level of testing: a minimum of 2 plantlets per clone/variety.	- Destroy all progeny of that clonal line - Retest all other aseptic clonal production in the affected facility. Level of testing: a minimum of 2 plantlets per clone/variety.	Destroy all progeny of that clonal line - Retest all other aseptic clonal production in the affected facility. Level of testing: 1% or a minimum of 5 plantlets to maximum of 50 plantlets per clone/ variety.	Destroy all production in the protected environment and conduct an investigation to determine risk of spread to farm unit.	If BRR is detected in field crops, a CFIA inspector may be able to verify aseptic techniques within nuclear production and the absence of contact with field grown crops, to prevent de-certification.
If PSTVd is detected	- Destroy material from the positive clone/ variety	- Destroy material from the positive clone/variety	- Destroy material from the positive clone/ variety	- Destroy material from the positive clone/variety
If positive for any regulated and non regulated pathogen	- Destroy all positive material	- Destroy all positive material	- Destroy all positive material	- Determine class eligibility for disease tolerance in Regulations. - If evidence of insect disease vector (see section 2.5.17)
The facility must maintain an information system	(see 2.1.5 for details)	(see 2.1.5 for details)	(see 2.1.5 for details)	(see 2.1.5 for details)
Document used for transfer of material	Nuclear Stock Certificates (for registered varieties shipped domestically) and unregistered varieties exported or Certificate of Authorization (for unregistered varieties)	N/A	Nuclear Stock Certificates (for registered varieties shipped domestically) and unregistered varieties exported or Certificate of Authorization (for unregistered varieties)	Nuclear Stock Certificates (for registered varieties shipped domestically) and unregistered varieties exported or Nuclear Stock Tags (for registered varieties shipped domestically) or Certificate of Authorization (for unregistered varieties)	See section 2.7 for information to be provided on document issued. Nuclear stock class seed potatoes produced in a protected environment and transferred to a new owner cannot be used to further produce Nuclear stock class seed potatoes.