| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Stralarivirus fragariae (strawberry latent ringspot virus) (SLRSV0)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Strawberry latent ringspot virus
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: Fruits (including hops) sector
If necessary, please list the species:
-
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Candidate: Fruits (including hops) sector
Justification (if necessary):
Strawberry latent ringspot virus (SLRSV) is a member of the family Secoviridae.
This virus can be detected and identified in host plants and nematode vectors by specific reverse transcription polymerase chain reaction assays (RT-PCR) and/or sequencing. Antisera are also available and widely used for virus surveys and monitoring as well as for indexing of planting materials to ensure freedom from viruses (EFSA PLH, 2013). RT-PCR is commonly used in olive, including in certification programs for the detection and characterization of such plant viruses (Faggioli et al., 2005; Çağlayan et al., 2008).
This virus can be detected and identified in host plants and nematode vectors by specific reverse transcription polymerase chain reaction assays (RT-PCR) and/or sequencing. Antisera are also available and widely used for virus surveys and monitoring as well as for indexing of planting materials to ensure freedom from viruses (EFSA PLH, 2013). RT-PCR is commonly used in olive, including in certification programs for the detection and characterization of such plant viruses (Faggioli et al., 2005; Çağlayan et al., 2008).
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
No
Presence in the EU:
Yes
List of countries (EPPO Global Database):
Belgium (2015); Croatia (2016); Czech Republic (1994); Finland (1996); France (1992); Germany (1993); Greece (2020); Greece/Kriti (2020); Hungary (1995); Ireland (1993); Italy (1993); Luxembourg (1992); Netherlands (2022); Poland (1992); Portugal (1992); Spain (2011)
Conclusion:
Candidate
Justification (if necessary):
SLRSV is widely distributed in the EPPO region. Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/). In the EPPO region, SLRSV has been reported in olive trees from Albania, Croatia, Italy, Lebanon, Portugal, Spain, Turkey and Tunisia (Albanese et al., 2012).
HOST PLANT N°1: Olea europaea (OLVEU) for the Fruits (including hops) sector.
Origin of the listing:
Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072
Plants for planting:
Plants intended for planting
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
Yes
Conclusion:
Evaluation continues
Justification (if necessary):
EPPO Standard PM 4/17 Certification scheme for olive trees and rootstock recommends testing for strawberry latent ringspot virus (SLRSV). Full assessment of the RNQP status of SLRSV was performed together with Arabis mosaic virus (ArMV) in 2021/2022 in the context of the revision of EPPO Standard PM 4/17. The RNQP status was considered justified by olive certification experts because of direct impact and to prevent infection of other hosts produced at the same place of production.
Although PL considered in responses to the questionnaire that plants for planting was not the main pathway, this was not supported by enough justification.
The Fruit SEWG recommended to revise the assessment of the RNQP status for SLRSV on olive, considering that evidence of unacceptable economic impact on olive was lacking.
Although PL considered in responses to the questionnaire that plants for planting was not the main pathway, this was not supported by enough justification.
The Fruit SEWG recommended to revise the assessment of the RNQP status for SLRSV on olive, considering that evidence of unacceptable economic impact on olive was lacking.
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:
The main hosts of SLRSV include strawberry and raspberry. SLRSV is naturally associated with wild plants.
Plants for planting is a significant pathway for the virus, either at local or long distance. In particular, the virus is known to be often transmitted through infected seeds (EFSA PLH, 2013), but seed transmission of SRLSV in olive plants has not been demonstrated (Albanese et al., 2012; Lister & Murant, 1967). Seeds could also serve as reservoirs for the viruses in the soil (EFSA PLH, 2013).
The virus is transmitted by the longidorid nematode Xiphinema diversicaudatum (EFSA PLH, 2013). X. diversicaudatum is considered to be the most widely distributed longidorid in Europe and has been reported from most European countries except Finland, Romania and some of the southern Mediterranean countries (EFSA PLH, 2013). Nematode movement is limited and the distances they move are dependent on the physical and chemical properties of the soil matrix. Horizontal spread for X. diversicaudatum estimated in laboratory experiments was 64 cm per year in heavy clay soil but only 14 cm per year in sandy soil. Thomas (1981) concluded that the spread of X. diversicaudatum in the absence of plants is very limited but in the presence of suitable host plants both species disperse at a rate of about 10 cm per month. Dissemination of the virus over greater distances can occur if nematode vectors are dispersed with soil movements caused by rain or erosion. Nematodes may be carried in the soil adhering to farm equipment and machinery or, occasionally, to the feet of birds and other animals. Some nematodes can also be dispersed by wind-blown soil dust; however, this is unlikely for longidorids which generally do not withstand desiccation (EFSA PLH, 2013). Therefore, nematode movement would only play a role locally when olive plants are grown in close proximity with other host crops.
The virus is also mechanically transmitted, through wounding and by grafting or vegetative propagation of its hosts (EFSA PLH, 2013). However, this can be prevented when appropriate production practices are implemented.
SLRSV is known to infect pollen but evidence that they are transmitted to plants via such contaminated pollen is inconclusive (EFSA PLH, 2013).
Plants for planting is considered to be a significant pathway compared to other pathways.
Plants for planting is a significant pathway for the virus, either at local or long distance. In particular, the virus is known to be often transmitted through infected seeds (EFSA PLH, 2013), but seed transmission of SRLSV in olive plants has not been demonstrated (Albanese et al., 2012; Lister & Murant, 1967). Seeds could also serve as reservoirs for the viruses in the soil (EFSA PLH, 2013).
The virus is transmitted by the longidorid nematode Xiphinema diversicaudatum (EFSA PLH, 2013). X. diversicaudatum is considered to be the most widely distributed longidorid in Europe and has been reported from most European countries except Finland, Romania and some of the southern Mediterranean countries (EFSA PLH, 2013). Nematode movement is limited and the distances they move are dependent on the physical and chemical properties of the soil matrix. Horizontal spread for X. diversicaudatum estimated in laboratory experiments was 64 cm per year in heavy clay soil but only 14 cm per year in sandy soil. Thomas (1981) concluded that the spread of X. diversicaudatum in the absence of plants is very limited but in the presence of suitable host plants both species disperse at a rate of about 10 cm per month. Dissemination of the virus over greater distances can occur if nematode vectors are dispersed with soil movements caused by rain or erosion. Nematodes may be carried in the soil adhering to farm equipment and machinery or, occasionally, to the feet of birds and other animals. Some nematodes can also be dispersed by wind-blown soil dust; however, this is unlikely for longidorids which generally do not withstand desiccation (EFSA PLH, 2013). Therefore, nematode movement would only play a role locally when olive plants are grown in close proximity with other host crops.
The virus is also mechanically transmitted, through wounding and by grafting or vegetative propagation of its hosts (EFSA PLH, 2013). However, this can be prevented when appropriate production practices are implemented.
SLRSV is known to infect pollen but evidence that they are transmitted to plants via such contaminated pollen is inconclusive (EFSA PLH, 2013).
Plants for planting is considered to be a significant pathway compared to other pathways.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
Severe symptoms consisting of small, pearshaped, puckered fruits with deformed kernels (bumpy fruits), narrow and twisted leaves, bushy growth and reduced size of trees were described in olive trees of the Italian cv. ‘Ascolana tenera’ affected by SLRSV. Similar symptoms were observed in cvs ‘Negrinha’ and ‘Galega’ in Portugal, associated with a severe reduced rooting ability of the cuttings. However, among 15 different olive cultivars with plants being affected by SLRSV in Portugal, only a few showed symptoms as was observed in Italy, and no symptoms are apparently associated with SLRSV infections in Spain. Previously, the ‘Raggiola’ and ‘Frantoio’ were considered different olive varieties due to morphological and agronomical dissimilarities. Ferreti et al. (2002) showed that the two cultivars are genetically identical and that their differentiations are due to the constant presence of SLRSV in ‘Raggiola’ and the repeated SLRSV absence in ‘Frantoio’. Rooting trials conducted by Roschetti et al. (2009) to compare SLRSV-infected ‘Raggiola’ with virus-free ‘Frantoio’ showed that the virus does not influence the rooting rate of olive cuttings, contrary to what had been previously reported in Portugal (Albanese et al., 2012).
Between 2002-2024, 12 000 olive mother plants were tested in Spain and only two positives for SLRSV were detected, without any symptoms.
Between 2002-2024, 12 000 olive mother plants were tested in Spain and only two positives for SLRSV were detected, without any symptoms.
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Minimal to Medium (depends on the cultivars)
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:
Direct impact: When revising EPPO Standard PM 4/17 Certification scheme for olive trees and rootstocks, the expert working group considered that controlling SLRSV in olive plant production could help preventing severe symptoms in some olive plant cultivars. However, during the RNQP Project part 2, the Fruit SEWG highlighted that symptoms caused by SLRSV are only reported for some olive cultivars. For most cultivars, direct economic impact was considered acceptable.
Indirect economic impact to other hosts: ArMV and SLRSV, which are commonly found in mixed infections, can cause diseases in strawberry and in raspberry. Symptoms vary depending on the host plant but also on the virus isolate, the plant cultivar, the season and the year. When revising EPPO Standard PM 4/17 Certification scheme for olive trees and rootstocks, the expert working group considered that other crops could be impacted because of host plants for planting produced at the same place of production than olive (as is the case in some Italian or Slovenian nurseries) and infected there via the soil adhering to farm equipment and machinery. During the RNQP Project part 2, the Fruit SEWG considered that several host plants are not regulated, and regulating olive plants more than others because of possible indirect economic impact was not justified.
Indirect economic impact to other hosts: ArMV and SLRSV, which are commonly found in mixed infections, can cause diseases in strawberry and in raspberry. Symptoms vary depending on the host plant but also on the virus isolate, the plant cultivar, the season and the year. When revising EPPO Standard PM 4/17 Certification scheme for olive trees and rootstocks, the expert working group considered that other crops could be impacted because of host plants for planting produced at the same place of production than olive (as is the case in some Italian or Slovenian nurseries) and infected there via the soil adhering to farm equipment and machinery. During the RNQP Project part 2, the Fruit SEWG considered that several host plants are not regulated, and regulating olive plants more than others because of possible indirect economic impact was not justified.
6 - Are there feasible and effective measures available to prevent the presence of the pest on the plants for planting at an incidence above a certain threshold (including zero) to avoid an unacceptable economic impact as regards the relevant host plants?
Yes
Conclusion:
Candidate
Justification:
Inclusion in a certification scheme: Experts considered that testing only when producing the nuclear stock was sufficient (regular testing for the maintenance of the nuclear stock was not considered necessary in regard to the fairly limited risk of reinfection via natural spread).
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Yes
Conclusion:
Candidate
Justification:
CONCLUSION ON THE STATUS:
Disqualified: economic impact is considered acceptable
8 - Tolerance level:
Is there a need to change the Tolerance level:
Yes
Proposed Tolerance levels:
Delisting
9 - Risk management measures:
Is there a need to change the Risk management measure:
Yes
Proposed Risk management measure:
Delisting
REFERENCES:
- Albanese G, Saponari M & Faggioli F (2012) Olive Germplasm – The Olive Cultivation, Table Olive and Olive Oil Industry in Italy. Chapter 6. Phytosanitary certification. Available at http://dx.doi.org/10.5772/51722
- Çağlayan K, Serçe Ç U & Gazel M (2008) Olive viruses. Characterization, diagnosis & management of plant viruses. Volume 1: industrial crops 2008 pp.305–339.
- EFSA PLH (2013) EFSA Panel on Plant Health (PLH). Scientific opinion on the risk to plant health posed by Arabis mosaic virus, Raspberry ringspot virus, Strawberry latent ringspot virus and Tomato black ring virus to the EU territory with the identification and evaluation of risk reduction options. EFSA Journal 11(10):3377, 83 pp. doi:10.2903/j.efsa.2013.3377
- Faggioli F, Ferreti L, Albanese G, Sciarroni R, Pasquini G, Lumia V & Barba M (2005) Distribution of olive tree viruses in Italy as revealed by one-step rt-PCR. Journal of plant pathology 87, 45–59.
- Ferreti L, Faggioli G, Pasquini G, Sciarroni R, Pannelli G, Baldoni L & Barba M (2002) Strawberry latent ringspot virus (SLRSV) cause of differentiation among Raggiola and Frantoio olive cultivars. Journal of plant pathology 84, 171–200.
- Lister RM & Murant AF (1967) Seed-transmission of nematode-borne viruses. Annals of Applied Biology 59, 49–62.
- Roschetti A, Ferretti L, Muzzalupo I, Pellegrini F, Albanese G & Faggioli F.(2009) Evaluation of the possible effect of virus infections on olive propagation. Petria 19 (1), 18–28.