CGN potato collection

Regeneration of potato at CGN is done through true (botanical) seed and aims to preserve genetic integrity and seed quality

Sowing and planting

Dormancy is common in true potato seed, especially in wild species like Solanum acaule, and may last one to two years. To enhance germination, seeds are treated with 700 ppm gibberellic acid (GA₃) for 20-24 hours in the dark to avoid GA₃ degradation by light. Prolonged exposure (e.g., 48 hours) may lead to abnormal seedlings. Vernalization is usually not required.

All plant material used has been tested and cleared of quarantine pathogens prior to sowing, in line with Dutch and EU regulations.

Seedlings are raised and transplanted without selection, aiming for a population of 20–25 plants per accession. Regeneration is performed either under greenhouse conditions using hand pollination with a pollen mixture of all plants, or in isolated field plots where insect pollination occurs. In field plots, spatial isolation is ensured by surrounding crops like wheat.

Harvesting

To minimize genetic drift, seed is harvested evenly across all plants within the accession. Identity is safeguarded by consistent field numbering throughout the process. After harvest, seeds are cleaned, documented, and returned to CGN, where they are processed, tested, and stored under controlled conditions.

Pest and Disease Management

Preventive measures include regular fungicide applications against late blight and fencing against wildlife. Pests such as beetles or aphids are treated when necessary. Sanitary practices are applied to avoid virus transmission during crop maintenance.

Within the European Union, only potato germplasm screened for quarantine diseases can be distributed to fulfill the requirements for an EU plant passport. Therefore, only accessions that have passed the obligatory phytosanitary tests before seed multiplication are included in the CGN-collection. Below, more information can be found on subjects regarding import, phytosanitary testing and distribution.

Phytosanitary procedures and quarantine organisms

Phytosanitary measurements are required by EU Directives to prevent the spread of potato pathogens from South America into the European Union. As the CGN potato collection only consists of botanical seeds, only true seed transmittable diseases present on the quarantine list need to be screened for. All plants used for rejuvenation had phytosanitary testing, conducted by the Netherlands Food and Consumer Product Safety Authority (NVWA).

Testing methods include:

• ovisual inspections of parent plants during regeneration;
• use of indicator plants such as and ;
• serological screening using DAS-ELISA;
• molecular tests such as RT-PCR for specific viroids and viruses.

Tested pathogens include:

• Andean potato latent virus (APLV)
• Andean potato mild mosaic virus (APMMV)
• Arracacha virus B – oca strain (AVB-O)
• Potato black ringspot virus (PBRsV)
• Potato virus T (PVT)
• Potato yellowing virus (PYV)
• Potato spindle tuber viroid (PSTVd)

The exact testing regime is updated based on EU directives and NVWA guidelines.

Distribution The germplasm is freely distributed in quantities of 50 seeds per sample. Selecting and ordering germplasm occurs through the online search facility (click 'View the crop collection' and select Potato). Users are requested to return their evaluation results to CGN.

CGN only distributes germplasm after the Standard Material Transfer Agreement (SMTA) is accepted. This is handled electronically via a click-wrap procedure. The 'Procedures' page provides information on the procedures CGN uses for seed distribution.

Within the EU, potato germplasm from CGN will be accompanied by a plant passport. The user is also required to supply a plant passport when distributing this germplasm or derived material to other users within the EU. Seed delivery within the EU may be delayed due to the requesting time of the Plant Passport required from the Dutch Plant Health Service. Once issued, CGN retrieves the seeds from storage and ships them to the user. Outside the EU, the limitations are determined by the regulations of the receiving country. Please inform CGN of any issues with germplasm quality or disease symptoms.