| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Phytophthora nicotianae var. parasitica (PHYTNP)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Phytophthora nicotianae var. parasitica (Phytophthora
parasitica)
parasitica)
Pest category:
Chromista
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):
Remarks:
- Fortunella is considered to be a synonym of Citrus by some authors. Using SSRs markers, Fortunella clusters within the genus Citrus (Barkley et al., 2006). These should be considered the same genus.
- Poncirus is considered to be a synonym of Citrus by some authors, and is categorized as such in EPPO GD. However, when using SSRs markers, Poncirus is a sister genus to Citrus (Barkley et al., 2006). In addition, one chromosomal marker can be used to distinguish Poncirus from Citrus species (Brasileiro Vidal et al., 2007). Whether to consider these as synonym or not is still a matter of debate.
- Fortunella is considered to be a synonym of Citrus by some authors. Using SSRs markers, Fortunella clusters within the genus Citrus (Barkley et al., 2006). These should be considered the same genus.
- Poncirus is considered to be a synonym of Citrus by some authors, and is categorized as such in EPPO GD. However, when using SSRs markers, Poncirus is a sister genus to Citrus (Barkley et al., 2006). In addition, one chromosomal marker can be used to distinguish Poncirus from Citrus species (Brasileiro Vidal et al., 2007). Whether to consider these as synonym or not is still a matter of debate.
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
No
Presence in the EU:
List of countries (EPPO Global Database):
-
Conclusion:
Justification (if necessary):
HOST PLANT N°1: Citrus (1CIDG) 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):
The Fruit SEWG questioned whether plants for planting should be considered as a significant pathway, as discussed for other Phytophthora species already assessed. Evaluation continues on the pathway criteria.
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
No
Conclusion:
Not candidate
Justification:
Citrus nursery plants have played a significant role in the dispersal of Phytophthora spp. in Citrus (Lucas and Beltran, 2004; Cacciola and Magnano di San Lio, 2007; Schutte and Boha, 2010; Savita and Nagal, 2012). For example, Schutte and Boha (2010) reports that, in South Africa, citrus plants for planting have been the main source of inoculum for Phytophthora spp.
However, in Spain, diseases caused by Phytophthora (both P. citrophthora and P. nicotianae) (Villalba, 1997; Alvarez et al., 2008) are an historic problem (the first affected plantations were detected in 1862), which in the past led to a radical change in the plant materials used as rootstocks in Spanish citriculture (Zaragoza, 1993). At the moment, Phytophthora spp. are commonly present in citrus soils (Álvarez et al., 2008; Vicent and Tusset, 2013) with presence of permanent inoculum (MAPA, 2022).
Similar situation occurs in other Citrus production areas of the EU: In Italy, Phytophthora epidemics of citrus were reported in 1855-1889 (Fawcett, 1936) a now the Phytophthora root rot of citrus caused by P. nicotianae var. parasitica and P. citrophthora is a serious widespread disease in this country, controlled by means of resistant rootstock, suitable irrigation and soil drainage (Ippolito et al., 1992). In Southern Italy, Ippolito et al. (1990) study shows existence of a large number of Phytophthora propagules in the citrus plantations studied.
In this context, considering the wide distribution of these pathogens in the main EU citrus-producing countries, the Fruit SEWG considered that plants for planting cannot be considered as a significant pathway of dispersal, compared to other sources of contamination, such as soil, natural dispersal from the surroundings etc., in areas where the pest is already present.
However, in Spain, diseases caused by Phytophthora (both P. citrophthora and P. nicotianae) (Villalba, 1997; Alvarez et al., 2008) are an historic problem (the first affected plantations were detected in 1862), which in the past led to a radical change in the plant materials used as rootstocks in Spanish citriculture (Zaragoza, 1993). At the moment, Phytophthora spp. are commonly present in citrus soils (Álvarez et al., 2008; Vicent and Tusset, 2013) with presence of permanent inoculum (MAPA, 2022).
Similar situation occurs in other Citrus production areas of the EU: In Italy, Phytophthora epidemics of citrus were reported in 1855-1889 (Fawcett, 1936) a now the Phytophthora root rot of citrus caused by P. nicotianae var. parasitica and P. citrophthora is a serious widespread disease in this country, controlled by means of resistant rootstock, suitable irrigation and soil drainage (Ippolito et al., 1992). In Southern Italy, Ippolito et al. (1990) study shows existence of a large number of Phytophthora propagules in the citrus plantations studied.
In this context, considering the wide distribution of these pathogens in the main EU citrus-producing countries, the Fruit SEWG considered that plants for planting cannot be considered as a significant pathway of dispersal, compared to other sources of contamination, such as soil, natural dispersal from the surroundings etc., in areas where the pest is already present.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Justification:
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
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?
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:
Justification:
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: plant for planting is not considered a significant pathway anymore in areas where the pest is present.
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:
- Alvarez LA, Vincent , De la Roca E, Bascon J, Abad-Campos P, Armengol J & Garcia-Jimenez J (2008) Branch cankers on citrus tres in Spain caused by Phytophthora citrophthora. Plant Pathology 57, 84-91. doi: 10.1111/j.1365-3059.2007.01702.x
- Barkley NA, Roose ML, Krueger RR & Federici CT (2006) Assessing genetic diversity and population structure in a citrus germplasm collection utilizing simple sequence repeat markers (SSRs). Theor Apple Genet. 112(8), 1519-31.
- Brasileiro-Vidal AC, Dos Santos-Serejo JA, Soares Filho Wdos S & Guerra M. (2007) A simple chromosomal marker can reliably distinguishes Poncirus from Citrus species. Genética 129(3), 273-9.
- Cacciola SO & Magnano Di San Lio G (2007) Management of Citrus diseases caused by Phytophthora sp. In “Integrated management and biocontrol of plant diseases caused by bacteria and fungi”. Ed. Ciancio A, Mukerji K.G.. Springer.
- Fawcett HS (1936) Citrus diseases and their control. Mac-Graw Hill Book Co. New York and London.
- Ippolito A, De Cicco V & Salerno M (1990) Role of Phytophthora spp.in citrus decline in Apulia and Basilicata, Italy. EPPO Bulletin 20, 91-94.
- Ippolito A, Lima G & Nigro F (1992) Influence of irrigation method on Phytophthora root rot of Citrus. Preliminary results. Phytopathologia Mediterranea 31, 170-174.
- Lucas A & Beltran C (2004) Phytophthora en cítricos, un problema de difícil solución. Vida Rural, 1 de septiembre, 56-62.
- MAPA (2022) Guía de gestión integrada de plagas: Cítricos. Ministerio de Agricultura, Pesca y Alimentación. https://www.mapa.gob.es/es/agricultura/temas/sanidad-vegetal/guiagipcitricos_vers2_tcm30-57942.pdf
- Savita GSV & Nagpal A (2012) Citrus diseases caused by Phytophthora species. GERF Bulletin of Biosciencies 3(1), 18-27.
- Schutte GC, Botha WJ (2010) Phytophthora citrophthora trunk and branch canker on Clementine mandarins in the Western Cape province of South Africa. South African Journal of Plant and Soil 27(3), 215-220.
- Vicent A & Tusset JJ (2013) Enfermedades causadas por Phytophthora en cítricos. Descripción y bases para su gestión integrada. Levante Agrícola, 4º trimestre 2013: 332-336.
- Villalba D (1997) Enfermedades producidas por hongos en los cítricos. Vida Rural 48, 41-44.
- Zaragoza S (1993) Past and present situation of the Spanish citrus industry. Valencia: Conselleria dÁgricultura i Pesca, D.L.