The Office for Risk Assessment & Research (BuRO) has investigated whether pests can be transmitted via strawberry seed. Based on a literature review, BuRO identified 5 viruses that are known to be seed-transmissible in strawberries, and there are indications that 2 other viruses may also be transmitted via strawberry seed. This report specifies which viruses are involved. No evidence was found for the transmission of other pests.

Reason for the BuRO study

Strawberry plants are usually propagated vegetatively (without seeds), but seed propagation is becoming increasingly important. Therefore, the National Plant Protection Organisation of the Netherlands (NPPO-NL) asked BuRO to identify which pests can be transmitted via strawberry seed. This information is crucial for the import of strawberry seeds and their movement within the EU. A follow-up question was which of these organisms are not currently regulated in the EU but could qualify for an EU quarantine status (EU-Q status).

Main findings and conclusions of BuRO

BuRO found no evidence in the literature of bacteria, fungi, or nematodes that are harmful to plants and have been proven to be transmitted via strawberry seed. While some fungi may be present on or in the seed, there is no evidence of actual transmission to plants. Transmission of plant-parasitic nematodes via strawberry seed appears unlikely, as these organisms rarely occur on strawberry fruits.

BuRO identified 5 viruses that have been proven to be seed-transmissible in strawberries:

  • Arabis mosaic virus (ArMV, Nepovirus arabis)
  • Beet ringspot virus (BRSV, Nepovirus betae)
  • Fragaria chiloensis latent virus (FCiLV, Ilarvirus FCILV)
  • Raspberry ringspot virus (RpRSV, Nepovirus rubri)
  • Strawberry necrotic shock virus (SNSV, Ilarvirus SNSV)

Additionally, BuRO found 2 viruses that may also be seed-transmissible, though the evidence is limited and not conclusive:

  • Fragaria chiloensis cryptic virus (FClCV)
  • Tomato ringspot virus (ToRSV, Nepovirus lycopersici)

Of these 7 viruses, 3 (BRSV, FCiLV, and FClCV) are not regulated in the EU. BuRO concludes that these viruses do not meet the criteria of an EU quarantine pest. BRSV is likely already widespread in the EU, while the introduction of FCiLV and FClCV is not expected to cause economic damage.

It is possible that more pests can be transmitted via strawberry seed than are currently known. Since seed propagation is relatively new, knowledge about the transmission of pests via seed is still limited.