EPPO RNQP

NAME OF THE ORGANISM: Shallot latent virus (SLV000)

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

Conclusion:

candidate

Justification (if necessary):

This pest was dentified in the Netherlands and Denmark, but similar viruses were recorded from England and France. It probably occurs world-wide (Bos, 1982). The pest has also been seen in Belgium, Czech Republic, Greece and Italy during reference searches.

HOST PLANT N°1: Allium porrum (ALLPO) 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 transmissible in a non-persistent manner by Myzus ascalonicus and perhaps by Aphis fabae, but not by M. persicae (Bos, 1982; Brunt et al., 1996) from other Allium crops or overwintered discarded plants. Plant material can be cleaned of infection by combining in vitro thermotherapy and meristem culture.
In conclusion, leeks are usually grown from seed, though whether it is seed transmissible it is not clear from the literature. However seedlings for transplanting could become infected via aphid transmission from infected hosts if not produced in contained secure environments, so seedlings could be considered a significant pathway.

5 - Economic impact:

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

Justification:

This virus causes mild chlorotic streaking in leek (A. porrum) when occurring alone, and severe chlorotic or white streaking and even plant death in some cultivars of leek when in complex with leek yellow stripe virus (Bos, 1982). No further details of its impact alone in leek could be found, however it has an apparent economic impact in combination with other viruses (Loebenstein & Lecoq, 2012).

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:

Experts concluded that Economic impact is considered acceptable.

CONCLUSION ON THE STATUS:

Disqualified: economic impact is considered acceptable. The pest will be covered by the general 'substantially free from' requirement.

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:

Bos L (1982) Descriptions of plant Viruses Shallot latent virus. Research Institute for Plant Protection, Wageningen, The Netherlands. Available at: http://www.dpvweb.net/dpv/showdpv.php?dpvno=250;
Brunt A A, Crabtree K, Dallwitz M J, Gibbs A J, Watson L. & Zurcher E J (1996 onwards) Plant Viruses Online: Descriptions and Lists from the VIDE Database. Version: 16th January 1997. Available at http://sdb.im.ac.cn/vide/descr716.htm;
Loebenstein G & Lecoq H (2012) Advances in virus research, volume 84. Viruses and Virus Diseases of Vegetables in the Mediterranean Basin. Academic Press. Elsevier. First edition;