EPPO RNQP

NAME OF THE ORGANISM: Leek yellow stripe virus (LYSV00)

GENERAL INFORMATION ON THE PEST

Name as submitted in the project specification (if different to the preferred name):

Pest category:

Viruses and viroids

1- Identity of the pest/Level of taxonomic listing:

Is the organism clearly a single taxonomic entity and can it be adequately distinguished from other entities of the same rank?

Yes

Is the pest defined at the species level or lower?:

Yes

Can listing of the pest at a taxonomic level higher than species be supported by scientific reasons or can species be identified within the taxonomic rank which are the (main) pests of concern?

Not relevant: Vegetable propagating and planting material (other than seeds) sector

Is it justified that the pest is listed at a taxonomic rank below species level?

Not relevant

Conclusion:

Candidate: Vegetable propagating and planting material (other than seeds) sector

2 – Status in the EU:

Is this pest already a quarantine pest for the whole EU?

Presence in the EU:

Yes

List of countries (EPPO Global Database):

Belgium (2006); Denmark (2006); Finland (2006); France (2006); Germany (2006); Greece (2006); Italy (2006); Italy/Sicilia (2006); Netherlands (2006); Slovenia (2006); Sweden (2006)

Conclusion:

candidate

Justification (if necessary):

Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/).

HOST PLANT N°1: Allium cepa Aggregatum types (Allium ascalonicum) (ALLAS) for the Vegetable propagating and planting material (other than seeds) sector.

Origin of the listing:

RNQP Questionnaire

Plants for planting:

Plants intended for planting

3 - Is the pest already listed in a PM4 standard on the concerned host plant?

Conclusion:

Evaluation continues

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):

Yes

Conclusion:

Candidate

Justification:

This virus is reported in literature in garlic, leek and shallot but not for onion (Compendium of Onion and Garlic Diseases, 2008), and has been found combined with OYDV in shallots in Slovenia. Shallot is very resistant but not immune and LYSV has been isolated from shallot plants grown near severely infected leek (Bos, 1981). LYSV is transmitted non-persistently by Aphis fabae and Myzus persicae but not through seed of leek (Bos, 1981).
As shallot bulbs are used for planting this is a pathway and could be a significant pathway for LYSV if not produced under secure conditions and are then grown in fields where appropriate cultivations (removal of alternate hosts) and controls against aphids, have been carried out.

5 - Economic impact:

Are there documented reports of any economic impact on the host?

Justification:

Onion yellow dwarf virus (OYDV), Leek yellow stripe virus (LYSV) and Garlic common latent virus (GCLV) are the most common viruses in Allium species in the Mediterranean region (Vončina et al., 2016) although no direct references of any impact of LYSV on shallot could be found. LYSV is considered to be anecdotic on shallot (Eric VERDIN, INRA Montfavet 2017, pers. com.).

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)

Minimal

Is the economic impact due to the presence of the pest on the named host plant for planting, acceptable to the propagation and end user sectors concerned?

Yes

Is there unacceptable economic impact caused to other hosts (or the same host with a different intended use) produced at the same place of production due to the transfer of the pest from the named host plant for planting?

Conclusion:

Not candidate

Justification:

CONCLUSION ON THE STATUS:

Disqualified: absence of unacceptable economic impact.

8 - Tolerance level:

Is there a need to change the Tolerance level:

Proposed Tolerance levels:

Not recommended for the RNQP status.

9 - Risk management measures:

Is there a need to change the Risk management measure:

Proposed Risk management measure:

Not recommended for the RNQP status.

REFERENCES:

Compendium of Onion and Garlic Diseases (2008) Second edition. The American Phytopathological Society;
Bos L (1981) Descriptions of plant Viruses Leek yellow stripe virus. Research Institute for Plant Protection, Wageningen, The Netherlands. Available at: http://www.dpvweb.net/dpv/showdpv.php?dpvno=240;