| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Soymovirus maculavaccinii (blueberry red ringspot virus) (BRRV00)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Blueberry red 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):
Note on taxonomy: Blueberry red ringspot virus has been shown in symptomatic cranberry providing the evidence that BRRV is associated with the red ringspot disease in cranberry (Polashock et al, 2009).
A literature search gives some conflicting information, and also becomes difficult due to differences in nomenclature in the record. It is probable that cranberry ringspot agent describes the same disease as red ringspot disease in cranberry (blueberry red ringspot virus).
Martin et al (2012) indicates that red ringspot disease in cranberry is caused by a distinct strain of blueberry red ringspot virus, citing Polashock et al (2009).
A literature search gives some conflicting information, and also becomes difficult due to differences in nomenclature in the record. It is probable that cranberry ringspot agent describes the same disease as red ringspot disease in cranberry (blueberry red ringspot virus).
Martin et al (2012) indicates that red ringspot disease in cranberry is caused by a distinct strain of blueberry red ringspot virus, citing Polashock et al (2009).
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):
-
Conclusion:
Candidate
Justification (if necessary):
BRRV is reported in Czech Republic (Petrzik et al., 2011), Poland (Paduch-Cichal et al., 2011), Slovenia (Mavrič Pleško et al., 2010; Petrzik et al., 2011). Experts highlighted the gap of knowledge on the distribution because of the absence of large scale testing.
HOST PLANT N°1: Vaccinium (1VACG) 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 4-18 Certification scheme for Vaccinium recommends testing for 'Blueberry red ringspot caulimovirus'. In responses to the questionnaire, FR, NL and PL supported deregulation in the EU. FR and NL arguing that the pest is not present in the EU; PL considering that plant for planting is not the main pathway. Evaluation continues on these criteria.
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:
For blueberry red ringspot virus, Vaccinium spp. are the only known hosts (Kim et al., 1981), e.g. northern high bush blueberry - Vaccinium corymbosum, rabbit-eye blueberry - V. virgatum, cranberry V. macrocarpon (Polashock et al., 2009) and V. formosum (V. australe, Ramsdell et al., 1987). The disease has been observed in many blueberry cultivars, including Blueray, Bluetta, Burlington, Cabot, Coville, Darrow, Earliblue and Rubel. The cultivar Jersey is apparently field-immune and the cultivar Bluecrop is field-resistant (Gillet & Ramsdell, 1988).
Infected plants used in propagation can be the source of virus spread due to symptoms variation within cultivars from softwood cuttings and undetectable symptoms on hardwood cuttings (Martin et al., 2013).
In New Jersey, BRRV has been observed to spread actively, but spread has not been reported in Michigan, suggesting an invertebrate vector that is present in New Jersey and not Michigan, but is still to be identified (Glasheen et al., 2002).
Infected plants used in propagation can be the source of virus spread due to symptoms variation within cultivars from softwood cuttings and undetectable symptoms on hardwood cuttings (Martin et al., 2013).
In New Jersey, BRRV has been observed to spread actively, but spread has not been reported in Michigan, suggesting an invertebrate vector that is present in New Jersey and not Michigan, but is still to be identified (Glasheen et al., 2002).
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
The symptoms appear as red rings on green stems and as red rings with pale green centers 2–3 mm in diameter or round red spots that can coalesce into blotches on older leaves in late summer. The rings on leaves were traditionally thought to be visible only on the upper surface of the leaves and this was used as a diagnostic character, but some cultivars exhibit the rings on both sides of the leaves. Occasionally, reddish rings appear on the developing green fruit, but are usually not apparent when fruit is fully ripe. Infected bushes of the cultivar ‘Ozarkblue’ exhibit deformed fruit that are not marketable (Cline et al., 2009). Many infected cultivars appear to bear a full crop. However, a limited study in Michigan reported a 25% crop loss in infected plants of the cultivar ‘Blueray’, but impact on yield in other cultivars is to be documented (Gillet, 1988 - cited in Martin et al., 2013).
Williford et al (2016) carried out a three year survey on yield and fruit maturation for two cultivars Star and Jewell (southern highbush blueberry), comparing systematically BRRSV infected plants with uninfected plants. When fruit was harvested over time, no consistent yield or berry weight reductions were observed due to BRRSV infection for either cultivar. The BRRSV infection in cv Star seemed to lead to a shorter fruit ripening period. It was concluded that for these two cultivars a BRRSV infection was relatively benign.
Williford et al (2016) carried out a three year survey on yield and fruit maturation for two cultivars Star and Jewell (southern highbush blueberry), comparing systematically BRRSV infected plants with uninfected plants. When fruit was harvested over time, no consistent yield or berry weight reductions were observed due to BRRSV infection for either cultivar. The BRRSV infection in cv Star seemed to lead to a shorter fruit ripening period. It was concluded that for these two cultivars a BRRSV infection was relatively benign.
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:
Reports on impact vary. Although in general propagation material is screened for viruses, no recent publications on impact is available after 1988. Most reports come from the USA.
The Fruit SEWG considered that the impact could be assessed as minor, but with a high uncertainty.
The Fruit SEWG considered that the impact could be assessed as minor, but with a high uncertainty.
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?
Conclusion:
Justification:
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Conclusion:
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:
- Caruso FL & Ramsdell DC (1995) Compendium of blueberry and cranberry diseases. American Phytopathological Society.
- Cline WO, Ballington JR & Polashock JJ (2009) Blueberry red ringspot observations and findings in North Carolina. Acta Horticulturae 810, 305–312.
- Gillett JM (1988) Physical and chemical properties of blueberry red ringspot virus. MSc Thesis, Michigan State University, East Lansing, MI, USA.
- Gillett JM & Ramsdell DC (1988) Blueberry red ringspot virus. Description Plant Viruses no 327. https://www.dpvweb.net/dpv/showdpv/?dpvno=327
- Glasheen BM, Polashock JJ, Lawrence DM Gillett JM, Ramsdell DC, Vorsa N & Hillman BI (2002) Cloning, sequencing, and promoter identification of Blueberry red ringspot virus, a member of the family Caulimoviridae with similarities to the “Soybean chlorotic mottle-like” genus. Archives of Virology 147: 2169–2186.
- Kim KS, Ramsdell DC, Gillett JM & Fulton JP (1981) Virions and ultrastructural changes associated with blueberry red ringspot disease. Phytopathology 71, 673-678.
- Martin RR, Polashock JJ & Tzanetakis IE (2012) New and emerging viruses of blueberry and cranberry. Viruses 4(11), 2831-2852.
- Mavrič Pleško I, Viršček Marn M & Koron D (2010). Detection of Blueberry red ringspot virus in highbush blueberry cv. ‘Coville’ in Slovenia. Julius-Kühn-Archiv 427, 204-205.
- Paduch-Cichal E, Kalinowska E, Chodorska M, Sala-Rejczak K & Nowak B (2011) Detection and identification of viruses of highbush blueberry and cranberry using serological elisa test and PCR technique. Acta Scientiarum Polonorum-Hortorum Cultus, 10(4), pp.201-215.
- Petrzik K, Přibylová J, Pleško IM & Spak J (2011) Complete genome sequences of blueberry red ringspot virus (Caulimoviridae) isolates from the Czech Republic and Slovenia. Arch Virol 156, 1901–1903 (2011). https://doi.org/10.1007/s00705-011-1077-x
- Polashock JJ, Ehlenfeldt MK & Croach JA (2009) Molecular Detection and Discrimination of Blueberry red ringspot virus Strains Causing Disease in Cultivated Blueberry and Cranberry. Plant Dis. 93, 727-733.
- Ramsdell DC, Kim KS & Fulton JP (1987) Red ringspot of blueberry. In Virus diseases of small fruits (eds Converse RH). United States Department of Agriculture, ARS, Agricultural handbook nr 631, 121-123.
- Williford LA, Savelle AT & Scherm H (2016). Effects of Blueberry red ringspot virus on yield and fruit maturation in southern highbush blueberry. Plant Disease 100(1), 171-174.