| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Nepovirus avii (cherry leaf roll virus) (CLRV00)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Cherry leaf roll 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):
Cherry leaf roll virus (CLRV) is a well characterized virus. It is a member of the subgroup C of the genus Nepovirus in the family Secoviridae. Complete genome sequences are available for the two genomic RNAs of CLRV. This virus can be detected by biological indexing. However, serological or molecular detection assays are preferred (EFSA PLH, 2014).
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):
Austria (2014); Belgium (2015); Bulgaria (1996); Croatia (2011); Czech Republic (2020); Finland (2011); France (2016); France/Corse (2016); Germany (1997); Greece (2020); Greece/Kriti (2020); Hungary (1996); Italy (2020); Netherlands (2022); Poland (2013); Portugal (1997); Romania (1986); Slovakia (2002); Spain (2011)
Conclusion:
candidate
Justification (if necessary):
CLRV 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/). CLRV was recorded on grapevine in Germany (Ipach et al., 2003) and Poland (Komorowska et al., 2012). It has been reported in olive trees from Croatia, Italy, Lebanon, Portugal, Spain and Turkey (Albanese et al., 2012). No systematic surveys of CLRV were performed in the EU on many of its natural woody hosts, including Actinidia spp, therefore its presence on these hosts is probably underestimated.
(Remark: In the EPPO region, CLRV is a quarantine pest for some countries e.g. Jordan, Morocco, Norway, Tunisia and Turkey. The virus had been recommended for regulation as a quarantine pest by EPPO from 1981 to 2004, see https://gd.eppo.int/taxon/CLRV00/categorization).
Detailed information
- on olive
A total of 245 olive trees representing 15 different cultivars from the FAO collection at the Centro de Investigación y Formación Agraria (CIFA), Córdoba (Spain), and other selections from different Spanish areas were tested, among other pathogens , for CLRV. One sample was found to be infected (Bertolini et al. 2006).
In an Italian study, 345 samples collected from olive fields in Italian areas in which national and local olive tree cultivars and selections are grown were tested for common viruses. The CLRV infection rate was 4.9% (Faggioli et al. 2005).
A survey on viruses infecting olive trees in Croatian Istria included a total of 62 olive trees from 15 varieties. The most frequent virus was CLRV, detected in 11.3% of tested trees both in autochthonous and in introduced varieties. Infected plants showed disease symptoms including yellowing of leaves and uneven fruit ripening (Godena et al. 2016).
(Remark: In the EPPO region, CLRV is a quarantine pest for some countries e.g. Jordan, Morocco, Norway, Tunisia and Turkey. The virus had been recommended for regulation as a quarantine pest by EPPO from 1981 to 2004, see https://gd.eppo.int/taxon/CLRV00/categorization).
Detailed information
- on olive
A total of 245 olive trees representing 15 different cultivars from the FAO collection at the Centro de Investigación y Formación Agraria (CIFA), Córdoba (Spain), and other selections from different Spanish areas were tested, among other pathogens , for CLRV. One sample was found to be infected (Bertolini et al. 2006).
In an Italian study, 345 samples collected from olive fields in Italian areas in which national and local olive tree cultivars and selections are grown were tested for common viruses. The CLRV infection rate was 4.9% (Faggioli et al. 2005).
A survey on viruses infecting olive trees in Croatian Istria included a total of 62 olive trees from 15 varieties. The most frequent virus was CLRV, detected in 11.3% of tested trees both in autochthonous and in introduced varieties. Infected plants showed disease symptoms including yellowing of leaves and uneven fruit ripening (Godena et al. 2016).
HOST PLANT N°1: Prunus avium (PRNAV) 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):
Listed as 'Cherry leaf roll nepovirus (CLRV)' in EPPO Standard PM 4-29 Certification scheme for cherry; with testing recommended.
PL considered in responses to the questionnaire that plants for planting was not the main pathway but this was not supported by enough justification.
Evaluation continues following a request by a member of the Fruit SEWG.
Remark: the assessment performed covers the given host species as well as interspecific hybrids with other Prunus species.
PL considered in responses to the questionnaire that plants for planting was not the main pathway but this was not supported by enough justification.
Evaluation continues following a request by a member of the Fruit SEWG.
Remark: the assessment performed covers the given host species as well as interspecific hybrids with other Prunus species.
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:
Although the virus is widespread in forest trees, spread by planting material seems significant. The pathogen is also seed and pollen-transmitted. In case of an introduction to a non-infected area/place/site by planting material, seed and pollen transmission vertical (resulting in infected seeds and, upon germination, seedlings) and horizontal (resulting in infection of the pollinated mother plant) could lead to a fast disease spread. Transfer between different host species via pollen seems rare (EFSA PLH 2014), in consequence infection of forest trees would be of low importance for cultivated species. No natural vectors have been recorded (Langer et al. 2010).
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
Few data available.
CLRV has a large host range, which includes woody and herbaceous species. Particularly, woody trees and shrubs are affected (Langer, 2010, EFSA PHL, 2014).
First reports on CLRV date back to the 1960s, when a leafroll disease of cherries was described in UK (Cropley, 1961). Since then, economically significant damage to cherry orchards in Europe and the middle east has only been described in isolated cases, despite the wide occurrence of the pathogen. CLRV infections of sweet cherries with an infection rate of 3% have been recorded in Romania. However, the paper does not state, whether samples were collected randomly or based on visual disease symptoms (Isac, 2008). In Turkey, in a survey published in 2004, one out of 48 virus symptomatic cherry trees tested positive for CLRV, and in a survey on cherry rootstocks in 2008, in one out of 43 symptomatic clonal rootstocks, CLRV was detected (Sertkaya et al., 2004; Sertkaya, 2008). In Serbia two variety collections with cultivars of sweet and sour cherry were tested for viruses, among them CLRV. Out of 80 plants tested by ELISA, none tested positive for CLRV (Mandic et al. 2007).
In USA mixed infections with Prunus necrotic ringspot virus (PNRSV) or Prune dwarf virus (PDV) have caused significant economic losses (Bush, 2005). Recently CLRV caused decline, rosetting (bunching of leaves owing to shortened internodes), and enation symptoms in sweet cherry trees in Oregon (Reinhold and Pscheit, 2023).
CLRV has a large host range, which includes woody and herbaceous species. Particularly, woody trees and shrubs are affected (Langer, 2010, EFSA PHL, 2014).
First reports on CLRV date back to the 1960s, when a leafroll disease of cherries was described in UK (Cropley, 1961). Since then, economically significant damage to cherry orchards in Europe and the middle east has only been described in isolated cases, despite the wide occurrence of the pathogen. CLRV infections of sweet cherries with an infection rate of 3% have been recorded in Romania. However, the paper does not state, whether samples were collected randomly or based on visual disease symptoms (Isac, 2008). In Turkey, in a survey published in 2004, one out of 48 virus symptomatic cherry trees tested positive for CLRV, and in a survey on cherry rootstocks in 2008, in one out of 43 symptomatic clonal rootstocks, CLRV was detected (Sertkaya et al., 2004; Sertkaya, 2008). In Serbia two variety collections with cultivars of sweet and sour cherry were tested for viruses, among them CLRV. Out of 80 plants tested by ELISA, none tested positive for CLRV (Mandic et al. 2007).
In USA mixed infections with Prunus necrotic ringspot virus (PNRSV) or Prune dwarf virus (PDV) have caused significant economic losses (Bush, 2005). Recently CLRV caused decline, rosetting (bunching of leaves owing to shortened internodes), and enation symptoms in sweet cherry trees in Oregon (Reinhold and Pscheit, 2023).
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Minor
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?
No
Conclusion:
Not candidate
Justification:
Pollen transmission can cause infection of neighboring crops (EFSA, PHL, 2014). The Fruit SEWG recommended not to consider indirect economic impact since interspecies infection is reported not to occur. Mechanical infection between different species is improbable since disinfection would prevent indirect economic impact.
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 certification scheme
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Conclusion:
Justification:
Few data on economic impact
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:
- Bush MR (2005) Cherry growers must contain the Cherry leaf roll virus- A new cherry disease to Pacific Northwest. Washington State University Extension, Yakima County http://treefruit. yakima.wsu.edu/pestmanagement/Pest%20Files/Cherry%20 Leaf%20Roll%20Virus%20in%20PNW.pdf
- Cropley R (1961) Cherry leaf roll virus. Ann. Appl. Biol. 49: 524–529.
- EFSA (2014) EFSA PLH Panel (EFSA Panel on Plant Health). Scientific Opinion on the pest categorisation of Cherry leafroll virus. EFSA Journal 2014, 12(10):3848, 23 pp. doi:10.2903/j.efsa.2014.3848
- Isac M, Plopa C, Calinescu M & Myrta A (2008) Detection of the viral diseases presently with the stone fruit species in Romania. Acta Hort. 781: 59–64
- Langer J, von Bargen S, Bandte M, Hamacher J, Büttner C (2010) Auftreten und Bedeutung des Cherry leaf roll virus in Laubbäumen am Beispiel von Steinfrüchten. Jahrbuch der Baumpflege 2010. https://www.agrar.hu-berlin.de/de/institut/departments/dntw/phytomedizin/pdf/publikationen/langer_etal2010
- Mandic B, Matić S, Al Rwahnih M, Jelkmann W & Myrta A (2007) Viruses of sweet and sour cherry in Serbia. Journal of Plant Pathology 89, no. 1, 103–108. http://www.jstor.org/stable/41998362.
- Reinhold LA & Pscheidt JW (2023) Diagnostic and Historical Surveys of Sweet Cherry (Prunus avium) Virus and Virus-Like Diseases in Oregon. Plant Dis. 107(3), 633-643. doi: 10.1094/PDIS-02-21-0327-SR.
- Sertaya G, Caglayan K & Ulubas C (2004) Detection of some viruses of stone fruits in mother blocks in Eastern Mediterranean Region of Turkey. Acta Hort. 657: 127–132.
- Sertaya G (2008) Serological detection of some viruses in cherry rootstocks in the Eastern Mediterranean Region of Turkey. Acta Hort. 795: 939–942