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D- 97-08: Production, Maintenance, Multiplication and Certification of Nuclear Stock Class Seed Potatoes

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Effective date: February 14, 2018
(5th Revision)

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.

This directive describes the technical standards for the initiation, maintenance and multiplication of in vitro plantlets and the production of micro-tubers and mini-tubers. It includes standards for pathogen testing, varietal purity, physical facilities and documentation.

This directive has been updated to align with the Seeds Regulations Part II in regards to document issuance.

Table of Contents

Review

This directive will be reviewed as required. For further information or clarification, please contact the Canadian Food Inspection Agency (CFIA).

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 aseptic and 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 through the conduct of crop inspections and CFIA required laboratory analysis.

Scope

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

This directive supersedes D-97-08 (4th Revision).

References

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

1.2 Fees

The CFIA charges fees in accordance with the Canadian Food Inspection Agency Fees Notice. For information regarding fees, please 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 environment through in vitro micro-propagation (i.e., tissue culture)

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

Multiplication: where pathogen-tested potato propagules are increased through vegetative propagation in an aseptic environment 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. Any specific exemptions are stated in sections 2.2 and 2.3.

2.1.1 With the exception of the Maintenance phase, growers must submit a complete Application for Seed Potato Crop Inspection - Growers Declaration (CFIA/ACIA 1317), pursuant to the Seeds Regulations Part II to the local CFIA office. If the nuclear stock facility or farm unit produces more than one of the following:

  1. Nuclear Stock in an aseptic environment,
  2. Nuclear Stock in a protected environment,
  3. field grown seed potatoes, it is recommended to submit a separate application to the CFIA for each type of production and to clearly identify the method of production being utilized.

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 facilities (i.e., with different grower numbers) is expected to pay the applicable fees for each application. For more information on fees, refer to D-95-13: Seed Potato Certification Program - Submission/Refund of Fees for Field Inspection.

2.1.2 A CFIA inspector must audit production practices and inspect plant material at facilities used in the production or initiation of Nuclear Stock class seed potatoes at least once a year during active crop production.

2.1.3 All Nuclear Stock material must be clearly labelled/identified at all times with the name of the variety/clone. Physical separation must be used between varieties/clones to prevent varietal mixture.

2.1.4 Cleaning and disinfection must be conducted as a routine practice before the establishment of the next crop of Nuclear Stock seed potatoes. A CFIA inspector may inspect the facility to verify proper cleaning and disinfection was conducted and that the sanitary conditions can be maintained until the next crop of Nuclear Stock is established.

2.1.5 A CFIA inspector or Regional Program Officer must issue a Growing Crop Certificate - Seed Potato (CFIA/ACIA 1318) for the material determined to meet the requirements of the Nuclear Stock class, pursuant to the Seeds Regulations Part II before any material is transferred to a new owner/grower.

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

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

Note: Each facility may establish its own coding techniques to maintain variety/clone identity and integrity during initiation, maintenance and multiplication.

2.1.7 Each crop under production must have valid disease testing results at all times during the multiplication process, with the exception of micro-tuber production, where valid disease testing results are required at the initiation of the micro-tuber production cycle. For details on testing rates, see sections 2.2.1.4, 2.2.2.1, 2.2.3.4, 2.2.4.1 and 2.3.13. Each crop must have been found free from the following organisms:

2.1.8 All disease tests must be carried out by a laboratory approved by the CFIA and are valid for a period of 12 months commencing on the date that the sample was received for testing to the approved laboratory. All relevant lab tests must be completed and the results must be reviewed by a CFIA inspector before a Growing Crop Certificate, a Nuclear Stock Tag or a Nuclear Stock Certificate can be issued. The date on the official laboratory testing report must be included on the Nuclear Stock Tags or Nuclear Stock Certificate accompanying the shipment. Disease test results are valid for 12 months and can be transferred with the plantlets as long as they are multiplied, planted and harvested within 12 months of the date the laboratory received the plantlets for testing. For details on mini-tuber and/or stem cutting testing, see section 2.3.12.

2.1.9 If the CFIA confirms the presence of C. m. sepedonicus, in a protected environment facility, all production from the affected facility will not be certified or certification will be revoked. However, a CFIA inspector may determine, based on verification of sanitation techniques utilized in the protected environment and separation with field grown production, that this disease was not in contact with field-grown production and field grown crops may retain their certification status.

2.1.10 If the CFIA confirms the presence of C. m. sepedonicus, in field grown potatoes, all field grown seed potato crops identified under the same application and produced by the same farm unit, will have their 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.

2.1.11 If a CFIA laboratory or a CFIA approved laboratory confirms the presence of PSTVd, the infected variety/clone will not be eligible for certification or certification will be revoked. All plant parts from any variety/clone that tests positive for PSTVd must be immediately removed from the facility.

2.2 Initiation, Maintenance and Multiplication in an Aseptic Environment

The following applies to the production of Nuclear Stock class seed potatoes in an aseptic environment.

2.2.1 General

2.2.1.1 A CFIA inspector must conduct an audit of each facility at least once a year during active production. Depending on the condition or appearance of the plantlets, the inspector may send samples to a CFIA laboratory for testing to determine if the material is free from regulated pathogens (section 2.1.7) or to confirm varietal purity. This audit must be recorded using a Nuclear Stock Aseptic Facility Inspection Report (CFIA/ACIA 5292). If the establishment does not meet program requirements, a Notification of Non-Compliance of Nuclear Stock Production Facility and Requirement for Corrective Action (CFIA/ACIA 5294) must be completed and provided to the grower as soon as possible. The facility may not be used to produce Nuclear Stock class seed potatoes until corrective actions have been taken and it has successfully passed a new audit.

2.2.1.2 The initiation, maintenance or multiplication facility must use recognized aseptic procedures to initiate, maintain and multiply Nuclear Stock (i.e., follow procedures and use equipment which will effectively maintain sterile conditions). Each facility must have a propagation procedures manual available for reference by staff as required.

2.2.1.3 Physical separation must exist between material being initiated, maintained, and/or multiplied. All initiation material must be labelled to differentiate them from other Nuclear Stock material.

2.2.1.4 Disease testing of plantlets in an aseptic environment must be carried out on a minimum of two plantlets for each variety/clone and each variety/clone must be found free from the diseases identified in section 2.1.7.

2.2.1.5 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(s) must be removed from the facility. For further details, see section 2.1.9 to 2.1.11.

2.2.1.6 In any case where a variety/clone tests positive or shows symptoms or signs of any bacterial or fungal contamination for any pathogen other than the ones listed in section 2.1.7, all the infected propagative material must be removed from the facility. All contaminated containers used in the propagative process must be removed from the production area immediately.

2.2.2 Initiation

Any potato material (i.e., any potato plant part, including stems and tubers) is acceptable for initiation into culture. It is eligible for entry into the seed potato certification program when the requirements specified in section 2.1 have been met.

2.2.2.1 If the CFIA confirms the presence of C. m. sepedonicus, in a newly initiated variety/clone, it is not eligible for certification. All other aseptic clonal production in 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. If the facility operates initiation and multiplication simultaneously, the testing requirements specified in section 2.2.4.1 and 2.3.13 may also apply.

2.2.3 Maintenance

The following applies to the maintenance of Nuclear Stock class seed potatoes in an aseptic environment.

2.2.3.1 Varietal or clonal integrity must be maintained by following the procedures outlined in the facility propagation procedures manual, which will prevent varietal mixture during all transfer, storage and handling activities.

2.2.3.2 There are no requirements for specific disease testing during the maintenance phase other than those requirements described in section 2.2.3.3 and 2.2.3.4.

2.2.3.3 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 (i.e., must comply with all components of section 2.2 (initiation and multiplication) and possess disease testing results as described in section 2.1.7).

2.2.3.4 If the CFIA confirms the presence of C. m. sepedonicus, in a variety/clone, it is not eligible for certification or certification will be revoked. All other aseptic clonal production in the affected facility, including material in the maintenance phase, will be subject to re-testing to verify freedom from C. m. sepedonicus. The level of testing for variety/clone(s) under maintenance will be a minimum of 2 plantlets per variety/clone.

2.2.4 Multiplication

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

2.2.4.1 If the CFIA confirms the presence of C. m. sepedonicus, in a variety/clone, it is not eligible for certification or certification will be revoked. All other production in the affected facility will be subject to re-testing to verify freedom from C. m. sepedonicus. The level of testing for each variety/clone under active multiplication will be 1% or a minimum of 5 plantlets to a maximum of 50 plantlets per clone. All testing requirements specified in section 2.3.13 may also apply.

2.3 Multiplication in a Protected Environment

In addition to the general requirements in section 2.1, the following applies to the multiplication of Nuclear Stock class seed potatoes in a protected environment.

2.3.1 The grower must notify the local CFIA office 10 working days prior to the proposed date of planting in order to allow sufficient time for a pre-planting inspection to be scheduled if the CFIA office determines that a pre-planting inspection is necessary. The grower must provide relevant information regarding the production and renovation history of the protected environment. A pre-plant inspection must be completed if any of the following conditions apply:

The pre-planting inspection and approval to plant should be recorded using a Nuclear Stock Protected Environment Inspection Report (CFIA/ACIA 5293 Part A). 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) must be completed and provided to the grower as soon as possible. The protected environment can not be used to produce Nuclear Stock class seed potatoes until corrective actions have been taken and it has successfully passed a new inspection.

2.3.2 In addition to the pre-planting inspection, the facility and the crops within the facility must be inspected by a CFIA inspector at least once during the growing cycle. Depending on the condition or appearance of the crops, the inspector may take samples for laboratory testing to be carried out by the CFIA to determine if a crop is free of regulated pathogens or to confirm varietal identity and purity. This inspection should be recorded using a Nuclear Stock Protected Environment Inspection Report (CFIA/ACIA 5293 Part B).

2.3.3 No plants other than those potato plants being produced for certification as Nuclear Stock and listed on the application (CFIA/ACIA 1317) may be present in the protected environment while Nuclear Stock is being grown. If there is a connection between protected environments, a secure pest-resistant physical separation must be present between Nuclear Stock seed potatoes and all other plants being grown in a different protected environment.

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

2.3.5 The entire protected environment must be cleaned and disinfected, and must be free from all plant debris prior to planting.

2.3.6 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 sticky traps for aphid monitoring, adoption of integrated pest management practices, records of any pests or diseases observed and corrective actions taken, etc.).

2.3.7 Nuclear Stock class propagative material must be planted in soil-free medium which has not been previously used to produce any crop.

2.3.8 If ground beds are used, the underlying soil must be separated by a new or a clean and 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 before each use.

2.3.9 The crop must be grown from Nuclear Stock class plantlets or micro-tubers which were produced in aseptic conditions, 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 that have been disease tested as per section 2.1.7.

2.3.10 Varieties/clones must be separated by physical barriers which will maintain varietal integrity and purity.

2.3.11 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 as described in section 2.3.12.

2.3.12 If first generation mini-tubers and/or stem cuttings are used to produce a second generation, a CFIA inspector shall not certify the second generation unless material from the first generation or the second generation have been tested by a laboratory approved by the CFIA and found to be free from the pathogens listed in section 2.1.7. All disease tests must have been carried out by a laboratory approved by the CFIA and they are valid for a period of 12 months commencing on the date that the sample was received for testing to the approved laboratory. In this instance, valid disease test results would be required at the time of planting of the crop used to produce the second generation or at the time of issuance of the growing crop certificate.

2.3.13 When additional pathogen testing is required on a crop producing mini-tubers (section 2.3.12), samples for virus and viroid testing should be collected at budding/flowering time (approximately 40 -70 days after planting) and for C. m. sepedonicus as per directive D-97-12 (Seed potato certification program - Bacterial ring rot testing program for field grown seed potatoes). Testing must be done 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 plants and when applicable, at least one tuber per plant, must be tested if the total number of plants of the clone is less than 5. All samples taken for required pathogen testing must be collected by or under the supervision of a CFIA inspector.

2.3.14 In the event that insect disease vectors, particularly aphids (wingless aphids, nymphs, adults, molting skins, dead and/or parasitized), are detected on or in the growing crop by a CFIA inspector, the grower must provide post-harvest test results to the CFIA.

After confirming the evidence of virus vectors in the protected environment, 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, if the results are negative for PVS, PVM, PVA, PVY and PLRV, the crop will be assigned Nuclear Stock class.

Failure to provide post-harvest test results, if required to do so, will result in the assignment of Pre-Elite class to all varieties/clones produced in the protected environment, provided that all applicable standards in the Seeds Regulations, Part II have been met.

2.3.15 If testing performed by a CFIA laboratory or a CFIA approved laboratory reveals the presence of PVA, PVS, PVM, PVY, PVX, or PLRV, the crop will be assigned the appropriate class based on standards specified in the Seeds Regulations, Part II and it will only be allowed to be grown for the next generation on the farm unit associated with the grower operating the protected environment.

2.4 Certification

2.4.1 For Nuclear Stock produced in a protected environment, the Application for Seed Potato Crop Inspection - Growers Declaration (CFIA/ACIA 1317) must be filed within thirty days after the earliest planting of the current crop(s) in the protected environment. (Note: the requirement to notify the local CFIA office in advance of planting stated in section 2.3.1 to allow for a pre-planting facility inspection, if deemed necessary by the CFIA, still applies). Amendments to the application (CFIA/ACIA 1317) can be made up to the time of inspection in the protected environment (budding or flowering time). A subsequent inspection may be required for those crops that have not reached the budding or flowering stage.

2.4.2 Facilities under continuous annual propagation and production in an aseptic environment must make a formal arrangement with the local CFIA office to ensure that the office is notified of new varieties introduced into the production cycle. This information must be recorded on the Application for Seed Potato Crop Inspection Growers Declaration (CFIA/ACIA 1317). Under these provisions, one annual application will suffice. CFIA inspectors will enter the information from each application (CFIA/ACIA 1317) in the CFIA Multi Commodity Activity Program database (MCAP) to facilitate traceability and various document issuance.

2.4.3 Following official inspections and required laboratory testing and if all the requirements under section 2.1, 2.2 or 2.3 have been met, the CFIA will grant certification for each variety/clone.

2.5 Transfer

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

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

2.5.3 Nuclear Stock class mini-tubers produced in a protected environment and transferred to a new owner cannot be used to produce a second generation of Nuclear Stock class seed potatoes.

3.0 Appendices

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

Criteria Initiation
(aseptic)
Maintenance
(aseptic)
Multiplication
(in an aseptic environment)
Multiplication
(in a protected environment)
Comments
An Application for Certification Must be Filed with the 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. Inform CFIA 10 working days prior to planting to determine if a pre-planting inspection is necessary (2.3.1).
The Application for Seed Potato Crop Inspection Growers Declaration (CFIA/ACIA 1317) for inspection of production must be filed within 30 days after the crop(s) have been planted. (2.4.1)
Use the Application for Seed Potato Crop Inspection Growers Declaration (CFIA/ACIA 1317). It is recommended that a separate page be used to differentiate between each type of production (i.e., aseptic and protected environment).
Audit/Inspection Requirements

If applicable, at least once a year as part of the overall multiplication facility audit process.

Recorded on CFIA/ACIA 5292 (2.2.1.1)

If applicable, at least once a year as part of the overall multiplication facility audit process.

Recorded on CFIA/ACIA 5292 (2.2.1.1)

Audited at least once during active production.

Recorded on CFIA/ACIA 5292 (2.2.1.1)

At least once, at or about budding / flowering time (40-70 days after planting) (2.3.2)
Plus, an optional pre-planting inspection (2.3.13)

Recorded on CFIA/ACIA 5293

If the facility does not meet program requirement, use form CFIA/ACIA 5294 to request corrective action.
Recognized Aseptic Initiation and/or Propagation Procedures Each facility must have a propagation procedure manual (2.2.1.2) Each facility must have a propagation procedure manual (2.2.1.2) Each facility must have a propagation procedure manual (2.2.1.2) The protected environment must be "Aphid proof". The producer must adopt a management program that includes effective sanitation practices (2.3.4 and 2.3.7).
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 at least that clone and all its progeny
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: There are no requirements for specific disease testing during the maintenance phase. (2.2.3.2)
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
Exception: Micro-tuber production - 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
Exception: Planting first generation mini-tubers and plant cuttings (2.3.11 and 2.3.12)
For clarification on determining the validity period, the recognized twelve month period will commence on the date that the samples were received to a CFIA approved laboratory. PMTV and PotLV testing are required only at the initiation phase.
If BRR is Detected C. m. sepedonicus (the causal agent of bacterial ring rot)

Not eligible for certification

Retest all other aseptic clonal production in the affected facility.
Level of testing:
a minimum of 2 plantlets per clone/variety. (2.2.2.1)

Not eligible for certification or certification revoked

Retest all other aseptic clonal production in the affected facility.
Level of testing:
a minimum of 2 plantlets per clone/variety. (2.2.3.4)

Not eligible for certification or certification revoked

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. (2.2.4.1)

Not eligible for certification or certification revoked

Conduct an investigation to determine risk of spread to associated farm units. (2.1.9)

If BRR is detected in field crops, a CFIA inspector will verify biosecurity practices applied and the absence of contact with field grown crops, to possibly prevent de-certification.
If PSTVd is Detected Remove material from the positive clone/variety (2.2.1.5) Remove material from the positive clone/variety (2.2.1.5) Remove material from the positive clone/variety (2.2.1.5) Remove material from the positive clone/variety (2.1.11) All remaining material will likely require testing for PSTVd.
If Positive for any Regulated and Non Regulated Pathogen Remove all positive material (2.2.1.6) Remove all positive material (2.2.1.6) Remove all positive material (2.2.1.6) Determine class eligibility for disease tolerance in Regulations. (2.3.15)
The Facility Must Maintain an Information System (2.1.6) (2.1.6) (2.1.6) (2.1.6)
Document Used for Transfer of Material N/A N/A Nuclear Stock Certificates
For all varieties shipped domestically and exported (2.5.1)
Nuclear Stock Certificates and/or Nuclear Stock Tags
For all varieties shipped domestically and exported (2.5.1)
See section 2.5 for information to be provided on document issued.
Nuclear stock class mini-tubers produced in a protected environment and transferred to a new owner cannot be used to further produce a second generation of Nuclear stock class seed potatoes. A North American Certified Seed Potato Health Certificate may be issued for seed potatoes exported to the United States.
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