| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Sadwavirus rubi (black raspberry necrosis virus) (BRNV00)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Black raspberry necrosis 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):
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):
BRNV is reported in Czech Republic (Fránová et al., 2023), Finland (Susi et al., 2018), Slovenia (Mavrič Pleško et al., 2012). The pest is considered to be present in many other countries in the EU (e.g. in the Netherlands, unpublished information).
HOST PLANT N°1: Rubus (1RUBG) 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 4-10 Certification scheme for Rubus recommends testing for Black raspberry necrosis virus in Rubus spp., mentionning that the virus is latent in most cvs of R. idaeus. In addition, PL considered in responses to the questionnaire that plants for planting was not the main pathway.
The Fruit SEWG recommended to further assess the relative importance of the pathways as well as the economic impact of this virus alone. Evaluation continues on these criteria.
The Fruit SEWG recommended to further assess the relative importance of the pathways as well as the economic impact of this virus alone. 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:
In nature, the virus is mostly restricted to Rubus species (Jones, 1988): it can infect black raspberry (Rubus occidentalis) – where it is a major component in decline of black raspberry plantings –, red raspberry (R. idaeus), evergreen blackberry (R. laciniatus), and ‘Marion’ blackberry (a complex hybrid with R. idaeus, R. armeniacus, and R. ursinus in its background), Himalaya blackberry (R. armeniacus), a weedy blackberry, and in Pacific blackberry (R. ursinus) found growing in field perimeters and hedgerows. Also other diverse hosts like western bracken fern (Pteridium aquilinum var. pubescens) and perennial sowthistle (Sonchus arvensis) were found infected with BRNV (Halgren, 2006).
BRNV is transmitted in nature by the raspberry aphids Amphorophora agathonica in North America and A. idaei in Europe. Under experimental conditions, these vectors and also Aulacorthum solani and Macrosiphum euphorbiae transmitted the virus to Chenopodium quinoa seedlings (Jones & Murant, 1972; Murant et al., 1976; Jones, 1976; Kurppa & Martin, 1986 – cited from Jones, 1988).
Almost all studies on vector relations have been done in North America using A. agathonica. All instars of A. agathonica can transmit the virus after minimum acquisition and inoculation access feeds of 15-30 min and 2 min respectively. Feeding aphids remain able to transmit the virus for up to 4 h after acquisition; starved aphids remain able to transmit the virus for up to 4 days, depending on the temperature (Stace-Smith, 1955). Transmission therefore seems to be in a semi-persistent manner.
Plant material can be considered a pathway for BRNV (Martin et al., 2013).
Although aphid species are active as a vector to the disease, once mother plants are infected with the virus, the spread with cuttings is very effective and close to 100% to the progeny.
The Fruit SEWG supported that plants for planting could still be considered as a significant pathway under protected cultivation.
BRNV is transmitted in nature by the raspberry aphids Amphorophora agathonica in North America and A. idaei in Europe. Under experimental conditions, these vectors and also Aulacorthum solani and Macrosiphum euphorbiae transmitted the virus to Chenopodium quinoa seedlings (Jones & Murant, 1972; Murant et al., 1976; Jones, 1976; Kurppa & Martin, 1986 – cited from Jones, 1988).
Almost all studies on vector relations have been done in North America using A. agathonica. All instars of A. agathonica can transmit the virus after minimum acquisition and inoculation access feeds of 15-30 min and 2 min respectively. Feeding aphids remain able to transmit the virus for up to 4 h after acquisition; starved aphids remain able to transmit the virus for up to 4 days, depending on the temperature (Stace-Smith, 1955). Transmission therefore seems to be in a semi-persistent manner.
Plant material can be considered a pathway for BRNV (Martin et al., 2013).
Although aphid species are active as a vector to the disease, once mother plants are infected with the virus, the spread with cuttings is very effective and close to 100% to the progeny.
The Fruit SEWG supported that plants for planting could still be considered as a significant pathway under protected cultivation.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
BRNV was reported to kill shoot tips (Jones, 1988): for biological indexing of red raspberry, the symptom of tip-necrosis of black raspberry was used as diagnostic tests for detection of BRNV. However, using molecular techniques, it became clear that the positive controls for BRNV were not only infected with BRNV, but also with one or more other viruses, which might alone or in combination be responsible for the symptom ‘tip necrosis’ (McGavin et al., 2010).
In the USA, BRNV is part of the raspberry mosaic disease complex. In the RMD complex in North America and Europe it seems that at least three viruses are involved in the symptom development including: Black raspberry necrosis virus (BRNV), Raspberry leaf mottle virus (RLMV) and Rubus yellow net virus (RYNV). In combination with raspberry bushy dwarf virus (RBDV), BRNV causes dwarfing and shoot proliferation in red raspberry, a typical bushy dwarf condition (Martin et al., 2013).
In Europe BRNV is often the first aphid-borne virus to arrive in a red raspberry plantation. It is again often found as part of a virus complex, e.g. vein banding mosaic virus together with rubus yellow net virus (RYNV) and raspberry leaf mottle virus (RLMV) (McMenemy et al. 2009).
On its own BRNV is often symptomless (Halgren, 2006; Martin et al., 2013), but sometimes the disease is distinguishable by the presence of small patches of leaf discoloration (McMenemy et al. 2009).
In the USA, BRNV is part of the raspberry mosaic disease complex. In the RMD complex in North America and Europe it seems that at least three viruses are involved in the symptom development including: Black raspberry necrosis virus (BRNV), Raspberry leaf mottle virus (RLMV) and Rubus yellow net virus (RYNV). In combination with raspberry bushy dwarf virus (RBDV), BRNV causes dwarfing and shoot proliferation in red raspberry, a typical bushy dwarf condition (Martin et al., 2013).
In Europe BRNV is often the first aphid-borne virus to arrive in a red raspberry plantation. It is again often found as part of a virus complex, e.g. vein banding mosaic virus together with rubus yellow net virus (RYNV) and raspberry leaf mottle virus (RLMV) (McMenemy et al. 2009).
On its own BRNV is often symptomless (Halgren, 2006; Martin et al., 2013), but sometimes the disease is distinguishable by the presence of small patches of leaf discoloration (McMenemy et al. 2009).
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:
Few Rubus viruses, including BNRV, produce characteristic symptoms in nursery plantings that would enable them to be eliminated from stock by rogueing. Experience has shown that stock, which has not been virus tested, is generally infected with one or more latent viruses. When planted, it usually lacks the vigour of certified stock and the planting gets off to a poor start. It is prone to rapid decline in fruit productivity and quality, as additional viruses are vectored into the planting and interact deleteriously with those already present in the planting stock. In the case of nursery production, efforts should be made to control all viruses (Martin et al., 2013).
The Fruit SEWG rated the economic impact as Minor (single infection with this virus). Since the effect of co-infection with other particular viruses was not considered clear enough, the SEWG assessed the economic impact of the virus on its own, which is considered acceptable.
The Fruit SEWG rated the economic impact as Minor (single infection with this virus). Since the effect of co-infection with other particular viruses was not considered clear enough, the SEWG assessed the economic impact of the virus on its own, which is considered acceptable.
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:
Justification:
(Re)infections can be controlled by normal containment measurements and control of aphids, in combination with the use of clean starting material.
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Yes
Conclusion:
Justification:
CONCLUSION ON THE STATUS:
Disqualified: economic impact on its own considered acceptable. No clear relation of co-infection with other particular viruses. Plants for planting is not considered to be a significant pathway compared to natural spread by aphids under outdoor conditions.
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:
- Fránová J, Koloniuk I, Lenz O, Přibylová J, Sarkisova T, Špak J, Tan LJ, Vinokurov K, Zemek R, Blystad D-R, Hamborg Z, Sapkota B, Spetz K, Trandem N, Čmejla R, Rejlová M, Sedlák J, Valentová L, Bilavčík A, Bobrova O, Faltus M, Hammond DSH, Zámečník J, Holub J & Skalík J (2023) Survey of raspberry viruses, associated arthropods and recovery of in vitro raspberry cultures in the Czech Republic and Norway. In book of abstracts The 25th International Conference on Virus and other Graft Transmissible Diseases of Fruit Crops. 9-13 July 2023 Wageningen, the Netherlands, page 60.
- Halgren AB (2006). Characterization, epidemiology, and ecology of a virus associated with black raspberry decline. Ph.D. Thesis. Oregon State University, Corvallis.
- Jones AT (1976) The effect of resistance to Amphorophora rubi in raspberry (Rubus idaeus) on the spread of aphid-borne viruses. Annals of Applied Biology 82, 503-510.
- Jones AT (1988) Black raspberry necrosis virus. In Description of Plant Viruses nr. 333. https://www.dpvweb.net/dpv/showdpv/?dpvno=333.
- Jones AT & Murant AT (1972) Some properties of a mechanically transmissible virus widespread in raspberry (Rubus idaeus) in Scotland. Plant Pathology 21, 166-170.
- Kurppa A & Martin RR (1986) Use of double-stranded RNA for detection and identification of virus diseases in Rubus species. Acta Horticulturae 186, 51-62.
- Martin RR, MacFarlane S, Sabanadzovic S, Quito D, Poudel B & Tzanetakis IE (2013) Viruses and virus diseases of Rubus. Plant Disease 97(2), 168-182. doi: 10.1094/PDIS-04-12-0362-FE. PMID: 30722311.
- McGavin WJ, McMenemy LS & MacFarlane SA (2010) The complete sequence of a UK strain of black raspberry necrosis virus. Archives of Virology 155, 1897–1899.
- McMenemy LS, Mitchell C & Johnson SN (2009) Biology of the European large raspberry aphid (Amphorophora idaei): its role in virus transmission and resistance breakdown in red raspberry. Agricultural and Forest Entomology 11, 61–71.
- Murant AF, Jones AT & Roberts IM (1976). Recent research on 52v virus of raspberry. Acta Horticulturae 66, 39-46.
- Mavrič Pleško I, Marn MV & Koron D (2012) Studies of Rubus viruses in Slovenia. Petria 22 (3), 351
- Sapkota B, Trandem N, Fránová J, Koloniuk I, Blystad DR & Hamborg Z (2024) Incidence of aphid-transmitted viruses in raspberry and raspberry aphids in Norway and experiments on aphid transmission of black raspberry necrosis virus. Frontiers in Plant Science, 15, 1441145.
- Stace-Smith R ( 1955) Studies on Rubus virus diseases in British Columbia. II. Black raspberry necrosis . Canadian Journal of Botany 33, 314 – 322.
- Susi H, Rajamäki ML, Artola K, Jayaraj‐Mallika FR & Valkonen JPT (2018). Molecular detection and characterisation of black raspberry necrosis virus and raspberry bushy dwarf virus isolates in wild raspberries. Annals of Applied Biology 173(2), 97-111.