National Reference Laboratory for Plant Health - Viruses, Viroids and Phytoplasmas, Sub-Division Potatoes

In general, seed potatoes may be marketed only if they have been officially examined and certified as basic seed potatoes or certified seed potatoes in accordance with the certification requirements. Basic seed potatoes and certified seed potatoes derived from pre-basic seed potatoes shall be certified only if the pre-basic seed potatoes are certified. Certified seed potatoes shall be certified only if they have been produced from certified pre-basic seed potatoes or certified basic seed potatoes.

Testing of potato planting material with regard to the requirements for quality includes testing for infestation with potato viroses PLRV (potato leafroll virus), PVY (potato virus Y), PVA (potato virus A), PVM (potato virus M), PVX (potato virus X) and PVS (potato virus S). Depending on the propagation category, a defined level of virus infestation is accepted. If no international standard methods are available for the detection of these viruses, methods are to be used which are preferably validated, internationally tested and recognized by the Federal Office for Food Safety.

Virus tests may be performed on tubers or on shoots or leaves grown from tubers or eye cuttings (EPPO PM 4/28). ELISA tests are performed on leaves of potato plants grown from tuber material (in the eye area) in the greenhouse. Since cultivation in the greenhouse takes at least four weeks, molecular biological detection directly from the tuber has been included in the methods for seeds and varieties according to § 5 Seed Act 1997 BGBl. I No. 72/1997 as amended Standards and Procedures for the Certification of Potato Seedlings.

Candidatus phytoplasma solani belongs to the group of stolbur phytoplasmas and is listed as a quarantine pathogen for potatoes. In stolbur disease of potato, plants wilt, tubers remain smaller, are deformed, and show rubbery consistency. Tubers of infected plants sprout threadbare and do not form vigorous plants. Laboratory testing is done according to methods for seeds and varieties in those lots where symptoms have been detected during official field inspection. Detection of phytoplasmas is done by real-time screening PCR. Subsequently, the phylogenetic group of Stolbur phytoplasmas (16S rRNA XII) is detected by endpoint PCR.

To protect plant health in agriculture and forestry and to prevent or monitor the introduction and spread of pests within the EU, international projects are working to harmonize plant protection regulations. In the course of the Euphresco "POVIRDET" project, molecular biological methods for the detection of Potato Virus T (PVT) and Andean Potato Mottel Virus (APMoV) are being tested.


Mag. Bernhard Föger

Last updated: 25.04.2022

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