List of non‐EU phytoplasmas of tuber‐forming Solanum spp.

Abstract

Following a request from the European Commission, the EFSA Panel on Plant Health prepared a list of non‐EU phytoplasmas of tuber‐forming Solanum spp. A systematic literature review and search of databases identified 12 phytoplasmas infecting S. tuberosum. These phytoplasmas were assigned to three categories. The first group (a) consists of seven non‐EU phytoplasmas, known to occur only outside the EU (‘Candidatus Phytoplasma americanum’, ‘Ca. P. australiense’, ‘Ca. P. fragariae’‐related strain (YN‐169, YN‐10G) and ‘Ca. P. hispanicum’) or having only limited presence in the EU (‘Ca. P. aurantifolia’–related strains, ‘Ca. P. pruni’‐related strains and ‘Ca. P. trifolii’). The second group (b) consists of three phytoplasmas originally described or reported from the EU. The third group (c) consists of two phytoplasmas with substantial presence in the EU, whose presence in S. tuberosum is not fully supported by the available literature. Phytoplasmas of categories (b) and (c) were excluded at this stage from further categorisation efforts. Three phytoplasmas from category (a) (‘Ca. P. australiense’, ‘Ca. P. hispanicum’ and ‘Ca. P. trifolii’) were excluded from further categorisation, as a pest categorisation has already been performed by EFSA. Comments provided by the EU Member States were integrated in the opinion. The main uncertainties of this listing concern: the taxonomy, the geographic distribution and prevalence and host range. The following phytoplasmas considered as non‐EU and whose presence in S. tuberosum is fully supported by literature (category (a)) are categorised by the Panel in a separate opinion: ‘Ca. P. americanum’, ‘Ca. P. fragariae’‐related strain (YN‐169, YN‐10G), ‘Ca. P. aurantifolia’–related strains and ‘Ca. P. pruni’‐related strains.

Introduction Background and Terms of Reference as provided by the requestor Background

Council Directive 2000/29/EC1 on protective measures against the introduction into the Community of organisms harmful to plants or plant products and against their spread within the Community establishes the present European Union plant health regime. The Directive lays down the phytosanitary provisions and the control checks to be carried out at the place of origin on plants and plant products destined for the Union or to be moved within the Union. In the Directive's 2000/29/EC annexes, the list of harmful organisms (pests) whose introduction into or spread within the Union is prohibited, is detailed together with specific requirements for import or internal movement.

Following the evaluation of the plant health regime, the new basic plant health law, Regulation (EU) 2016/20312 on protective measures against pests of plants, was adopted on 26 October 2016 and will apply from 14 December 2019 onwards, repealing Directive 2000/29/EC. In line with the principles of the above mentioned legislation and the follow-up work of the secondary legislation for the listing of EU regulated pests, EFSA is requested to provide pest categorisations of the harmful organisms included in the annexes of Directive 2000/29/EC, in the cases where recent pest risk assessment/ pest categorisation is not available.

Terms of Reference

EFSA is requested, pursuant to Article 22(5.b) and Article 29(1) of Regulation (EC) No 178/20023, to provide scientific opinion in the field of plant health.

EFSA is requested to prepare and deliver a pest categorisation (step 1 analysis) for each of the regulated pests included in the appendices of the annex to this mandate. The methodology and template of pest categorisation have already been developed in past mandates for the organisms listed in Annex II Part A Section II of Directive 2000/29/EC. The same methodology and outcome is expected for this work as well.

The list of the harmful organisms included in the annex to this mandate comprises 133 harmful organisms or groups. A pest categorisation is expected for these 133 pests or groups and the delivery of the work would be stepwise at regular intervals through the year as detailed below. First priority covers the harmful organisms included in Appendix 1, comprising pests from Annex II Part A Section I and Annex II Part B of Directive 2000/29/EC. The delivery of all pest categorisations for the pests included in Appendix 1 is June 2018. The second priority is the pests included in Appendix 2, comprising the group of Cicadellidae (non-EU) known to be vector of Pierce's disease (caused by Xylella fastidiosa), the group of Tephritidae (non-EU), the group of potato viruses and virus-like organisms, the group of viruses and virus-like organisms of Cydonia Mill., Fragaria L., Malus Mill., Prunus L., Pyrus L., Ribes L., Rubus L. and Vitis L. and the group of Margarodes (non-EU species). The delivery of all pest categorisations for the pests included in Appendix 2 is end 2019. The pests included in Appendix 3 cover pests of Annex I part A section I and all pests categorisations should be delivered by end 2020.

For the above-mentioned groups, each covering a large number of pests, the pest categorisation will be performed for the group and not the individual harmful organisms listed under “such as” notation in the Annexes of the Directive 2000/29/EC. The criteria to be taken particularly under consideration for these cases, is the analysis of host pest combination, investigation of pathways, the damages occurring and the relevant impact.

Finally, as indicated in the text above, all references to ‘non-European’ should be avoided and replaced by ‘non-EU’ and refer to all territories with exception of the Union territories as defined in Article 1 point 3 of Regulation (EU) 2016/2031.

Terms of Reference: Appendix 1

List of harmful organisms for which a pest categorisation is requested. The list below follows the annexes of Directive 2000/29/EC.

Annex IIAI
(a) Insects, mites and nematodes, at all stages of their development
Aleurocanthus spp.	Numonia pyrivorella (Matsumura)
Anthonomus bisignifer (Schenkling)	Oligonychus perditus Pritchard and Baker
Anthonomus signatus (Say)	Pissodes spp. (non-EU)
Aschistonyx eppoi Inouye	Scirtothrips aurantii Faure
Carposina niponensis Walsingham	Scirtothrips citri (Moultex)
Enarmonia packardi (Zeller)	Scolytidae spp. (non-EU)
Enarmonia prunivora Walsh	Scrobipalpopsis solanivora Povolny
Grapholita inopinata Heinrich	Tachypterellus quadrigibbus Say
Hishomonus phycitis	Toxoptera citricida Kirk.
Leucaspis japonica Ckll.	Unaspis citri Comstock
Listronotus bonariensis (Kuschel)
(b) Bacteria
Citrus variegated chlorosis	Xanthomonas campestris pv. oryzae (Ishiyama) Dye and pv. oryzicola (Fang. et al.) Dye
Erwinia stewartii (Smith) Dye
(c) Fungi
Alternaria alternata (Fr.) Keissler (non-EU pathogenic isolates)	Elsinoe spp. Bitanc. and Jenk. Mendes
Anisogramma anomala (Peck) E. Müller	Fusarium oxysporum f. sp. albedinis (Kilian and Maire) Gordon
Apiosporina morbosa (Schwein.) v. Arx	Guignardia piricola (Nosa) Yamamoto
Ceratocystis virescens (Davidson) Moreau	Puccinia pittieriana Hennings
Cercoseptoria pini-densiflorae (Hori and Nambu) Deighton	Stegophora ulmea (Schweinitz: Fries) Sydow & Sydow
Cercospora angolensis Carv. and Mendes	Venturia nashicola Tanaka and Yamamoto
(d) Virus and virus-like organisms
Beet curly top virus (non-EU isolates)	Citrus tristeza virus (non-EU isolates)
Black raspberry latent virus	Leprosis
Blight and blight-like	Little cherry pathogen (non- EU isolates)
Cadang-Cadang viroid	Naturally spreading psorosis
Palm lethal yellowing mycoplasm	Tatter leaf virus
Satsuma dwarf virus	Witches’ broom (MLO)
Annex IIB
(a) Insect mites and nematodes, at all stages of their development
Anthonomus grandis (Boh.)	Ips cembrae Heer
Cephalcia lariciphila (Klug)	Ips duplicatus Sahlberg
Dendroctonus micans Kugelan	Ips sexdentatus Börner
Gilphinia hercyniae (Hartig)	Ips typographus Heer
Gonipterus scutellatus Gyll.	Sternochetus mangiferae Fabricius
Ips amitinus Eichhof
(b) Bacteria
Curtobacterium flaccumfaciens pv. flaccumfaciens (Hedges) Collins and Jones
(c) Fungi
Glomerella gossypii Edgerton	Hypoxylon mammatum (Wahl.) J. Miller
Gremmeniella abietina (Lag.) Morelet

Terms of Reference: Appendix 2

List of harmful organisms for which a pest categorisation is requested per group. The list below follows the categorisation included in the annexes of Directive 2000/29/EC.

Annex IAI
(a) Insects, mites and nematodes, at all stages of their development
Group of Cicadellidae (non-EU) known to be vector of Pierce's disease (caused by Xylella fastidiosa), such as:
1) Carneocephala fulgida Nottingham	3) Graphocephala atropunctata (Signoret)
2) Draeculacephala minerva Ball
Group of Tephritidae (non-EU) such as:
1) Anastrepha fraterculus (Wiedemann)	12) Pardalaspis cyanescens Bezzi
2) Anastrepha ludens (Loew)	13) Pardalaspis quinaria Bezzi
3) Anastrepha obliqua Macquart	14) Pterandrus rosa (Karsch)
4) Anastrepha suspensa (Loew)	15) Rhacochlaena japonica Ito
5) Dacus ciliatus Loew	16) Rhagoletis completa Cresson
6) Dacus curcurbitae Coquillet	17) Rhagoletis fausta (Osten-Sacken)
7) Dacus dorsalis Hendel	18) Rhagoletis indifferens Curran
8) Dacus tryoni (Froggatt)	19) Rhagoletis mendax Curran
9) Dacus tsuneonis Miyake	20) Rhagoletis pomonella Walsh
10) Dacus zonatus Saund.	21) Rhagoletis suavis (Loew)
11) Epochra canadensis (Loew)
(c) Viruses and virus-like organisms
Group of potato viruses and virus-like organisms such as:
1) Andean potato latent virus	5) Potato virus T
2) Andean potato mottle virus	6) non-EU isolates of potato viruses A, M, S, V, X and Y (including Yo, Yn and Yc) and Potato leafroll virus
3) Arracacha virus B, oca strain
4) Potato black ringspot virus
Group of viruses and virus-like organisms of Cydonia Mill., Fragaria L., Malus Mill., Prunus L., Pyrus L., Ribes L., Rubus L. and Vitis L., such as:
1) Blueberry leaf mottle virus	8) Peach yellows mycoplasm
2) Cherry rasp leaf virus (American)	9) Plum line pattern virus (American)
3) Peach mosaic virus (American)	10) Raspberry leaf curl virus (American)
4) Peach phony rickettsia	11) Strawberry witches’ broom mycoplasma
5) Peach rosette mosaic virus	12) Non-EU viruses and virus-like organisms of Cydonia Mill., Fragaria L., Malus Mill., Prunus L., Pyrus L., Ribes L., Rubus L. and Vitis L.
6) Peach rosette mycoplasm
7) Peach X-disease mycoplasm
Annex IIAI
(a) Insects, mites and nematodes, at all stages of their development
Group of Margarodes (non-EU species) such as:
1) Margarodes vitis (Phillipi)	3) Margarodes prieskaensis Jakubski
2) Margarodes vredendalensis de Klerk

Terms of Reference: Appendix 3

List of harmful organisms for which a pest categorisation is requested. The list below follows the annexes of Directive 2000/29/EC.

Annex IAI
(a) Insects, mites and nematodes, at all stages of their development
Acleris spp. (non-EU)	Longidorus diadecturus Eveleigh and Allen
Amauromyza maculosa (Malloch)	Monochamus spp. (non-EU)
Anomala orientalis Waterhouse	Myndus crudus Van Duzee
Arrhenodes minutus Drury	Nacobbus aberrans (Thorne) Thorne and Allen
Choristoneura spp. (non-EU)	Naupactus leucoloma Boheman
Conotrachelus nenuphar (Herbst)	Premnotrypes spp. (non-EU)
Dendrolimus sibiricus Tschetverikov	Pseudopityophthorus minutissimus (Zimmermann)
Diabrotica barberi Smith and Lawrence	Pseudopityophthorus pruinosus (Eichhoff)
Diabrotica undecimpunctata howardi Barber	Scaphoideus luteolus (Van Duzee)
Diabrotica undecimpunctata undecimpunctata Mannerheim	Spodoptera eridania (Cramer)
Diabrotica virgifera zeae Krysan & Smith	Spodoptera frugiperda (Smith)
Diaphorina citri Kuway	Spodoptera litura (Fabricus)
Heliothis zea (Boddie)	Thrips palmi Karny
Hirschmanniella spp., other than Hirschmanniella gracilis (de Man) Luc and Goodey	Xiphinema americanum Cobb sensu lato (non-EU populations)
Liriomyza sativae Blanchard	Xiphinema californicum Lamberti and Bleve-Zacheo
(b) Fungi
Ceratocystis fagacearum (Bretz) Hunt	Mycosphaerella larici-leptolepis Ito et al.
Chrysomyxa arctostaphyli Dietel	Mycosphaerella populorum G. E. Thompson
Cronartium spp. (non-EU)	Phoma andina Turkensteen
Endocronartium spp. (non-EU)	Phyllosticta solitaria Ell. and Ev.
Guignardia laricina (Saw.) Yamamoto and Ito	Septoria lycopersici Speg. var. malagutii Ciccarone and Boerema
Gymnosporangium spp. (non-EU)	Thecaphora solani Barrus
Inonotus weirii (Murril) Kotlaba and Pouzar	Trechispora brinkmannii (Bresad.) Rogers
Melampsora farlowii (Arthur) Davis
(c) Viruses and virus-like organisms
Tobacco ringspot virus	Pepper mild tigré virus
Tomato ringspot virus	Squash leaf curl virus
Bean golden mosaic virus	Euphorbia mosaic virus
Cowpea mild mottle virus	Florida tomato virus
Lettuce infectious yellows virus
(d) Parasitic plants
Arceuthobium spp. (non-EU)
Annex IAII
(a) Insects, mites and nematodes, at all stages of their development
Meloidogyne fallax Karssen	Rhizoecus hibisci Kawai and Takagi
Popillia japonica Newman
(b) Bacteria
Clavibacter michiganensis (Smith) Davis et al. ssp. sepedonicus (Spieckermann and Kotthoff) Davis et al.	Ralstonia solanacearum (Smith) Yabuuchi et al.
(c) Fungi
Melampsora medusae Thümen	Synchytrium endobioticum (Schilbersky) Percival
Annex I B
(a) Insects, mites and nematodes, at all stages of their development
Leptinotarsa decemlineata Say	Liriomyza bryoniae (Kaltenbach)
(b) Viruses and virus-like organisms
Beet necrotic yellow vein virus

Interpretation of the Terms of Reference

This opinion provides a list of non-EU phytoplasmas of tuber-forming Solanum spp., for which the EFSA Plant Health Panel (from now on: “the Panel”) then conducted a pest categorisation in a separate opinion (EFSA PLH Panel et al., 2020b). This list is based on information collected from databases up to January 2020, as well as information received from EU Member States (MS) during the period April-June 2020.

The search conducted for this list made it clear that the only tuber-forming species of Solanum genus reported to be infected by phytoplasmas is S. tuberosum.

Non-EU phytoplasmas of S. tuberosum are pests listed in the Appendices to the Terms of Reference (ToR) to be subject to pest categorisation to determine whether they fulfil the criteria of quarantine pests or those of regulated non-quarantine pests for the area of the EU excluding Ceuta, Melilla and the outermost regions of MS referred to in Article 355(1) of the Treaty on the Functioning of the European Union (TFEU), other than Madeira and the Azores.

As a first step toward this goal, the Panel prepared a list of phytoplasmas infecting S. tuberosum. In the process, three groups of phytoplasmas were distinguished:

• a)non-EU phytoplasmas with presence in S. tuberosum fully supported by literature,
• b)phytoplasmas (affecting S. tuberosum) with widespread presence in the EU (known to occur in several MS, frequently reported in the EU, widespread in some MS) or originally described or reported from the EU, and
• c)phytoplasmas of category (b) but with presence in S. tuberosum not fully supported by the literature.

A non-EU phytoplasma is defined by its geographical origin outside of the EU. Therefore, phytoplasmas not reported from the EU and occurring only outside of the EU are considered as non-EU phytoplasmas. Likewise, phytoplasmas occurring outside the EU and having only a limited presence in the EU (reported in only one or few MSs, with restricted distribution) are also considered as non-EU phytoplasmas.

This opinion provides the methodology and results for this classification, thus preparing the ground for the pest categorisation linked to the present mandate (EFSA PLH Panel et al. 2020b). This means that the Panel then performed a pest categorisation for the non-EU phytoplasmas with confirmed ability to infect S. tuberosum. The phytoplasmas with uncertain ability to infect S. tuberosum and the phytoplasmas with significant presence in the EU or originally described or reported from the EU are excluded from further categorisation efforts, unless this will be requested by the risk managers in the future.

In this opinion, to capture the broadest possible range of phytoplasmas, even the poorly characterised ones for which very partial molecular or biological data are available, were considered. As in some cases there is uncertainty about the ‘Ca. P. species definition’, related strains were considered if they infect S. tuberosum. Instead, phytoplasma-like diseases of unknown aetiology or caused by viruses and formerly associated to mycoplasma-like organisms (MLO) or by other graft-transmissible bacteria are not addressed in this opinion.

Data and methodologies Data Literature search

The literature considered to generate the list of phytoplasmas infecting S. tuberosum (see Section 1.1.3) and to fill in the extraction tables on their distribution (see Appendices A–C and Annex A) was obtained from expert knowledge and extensive literature searches performed in Web of Science (WoS, last access January 2020). The search in WoS was performed using as keywords: phytoplasma/mycoplasma/witch/spiroplasma combined with the scientific name of the genus OR the common name of the crop. Therefore, the search in WoS was performed according to the following strategy:

TOPIC:((Phytoplasma* OR mycoplasma* OR witch* OR spiroplasma*) AND (Solanum OR potato*))

All the references were screened by title, abstract and, if needed, full paper with the specific objective of selecting those providing additional information regarding distribution and host range of the phytoplasmas included in the list or not yet included.

Information on phytoplasma taxonomy was gathered from either the original reference to species description or IRPCM (International Research Programme on Comparative Mycoplasmology) Phytoplasma/Spiroplasma Working Team–Phytoplasma Taxonomy Group (IRPCM, 2004).

Further references and data were obtained from experts, EU National Plant Protection Organisations and from citations within primary references.

Database search

Data on S. tuberosum as natural host and distribution of the phytoplasmas were retrieved from the EPPO Global Database (GD) (EPPO, 2020), the Centre for Agriculture and Biosciences International (CABI) Crop Protection Compendium (CABI, 2020) and relevant publications.

GenBank accessions referring to phytoplasmas were added.

Methodology

A preliminary list of phytoplasmas infecting S. tuberosum (see Section 1.1.3) was generated by screening for phytoplasma diseases of the species present in the EPPO Lists A1 and A2. Further, all phytoplasma diseases listed in the EPPO GD were also screened for their association with S. tuberosum. Finally, the relevant phytoplasmas resulting from the literature search in WoS (as previously described) were included in the list.

The collected information was used to fill an extraction table (Annex A) with data regarding the taxonomy, geographical distribution of each S. tuberosum-infecting phytoplasma and key references and sources used to obtain that information. Taxonomy and distribution are reported in the table using the following scheme:

• – the taxonomy was reported according to the ‘Ca. P. species’ description, when available. Although phytoplasmas have not yet been cultivated in vitro, phylogenetic analyses based on various conserved genes have shown that they represent a distinct, monophyletic clade within the class Mollicutes. Phytoplasmas are therefore accommodated within the ‘Candidatus Phytoplasma’ genus. Within this genus, several subtaxa have been described to accommodate organisms sharing less than 97.5% similarity among their 16S rRNA gene sequences. Additional species are described to accommodate organisms that, despite their 16S rRNA gene sequence being > 97.5% similar to those of other ‘Ca. Phytoplasma’ species, are characterised by distinctive biological, phytopathological and genetic properties. Conversely, some organisms, despite their 16S rRNA gene sequence being < 97.5% similar to that of any other ‘Ca. Phytoplasma’ species, are not presently described as Candidatus species, due to their poor overall characterisation (IRPCM, 2004). When a phytoplasma has not been classified yet, information on a tentative classification was included based on the original literature source in which the pathogen was reported; to facilitate data retrieval from the literature and available databases, also the 16S rRNA group and subgroups were reported.
• – data on distribution and on S. tuberosum as natural host of phytoplasmas were first searched in EPPO (2020) and in CABI (2020). Whenever conclusive information was not identified in the two databases or the information retrieved was at odds with expert knowledge, or in the absence of any information, extensive literature searches according to the protocol reported in Section 2.1 were performed.

Because only the non-EU phytoplasmas were subject of further categorisation efforts in the frame of the present mandate, it was decided to have consultation phases with EU Member States (MS) so that they could provide additional input if necessary. The information provided by EU MS was then considered by the Panel to determine the non-EU phytoplasmas that were further categorised (Section 3.1). The phytoplasmas excluded from this group are referred to here as phytoplasmas excluded from further categorisation in the frame of the present mandate (Section 3.2).

Listing of phytoplasmas Phytoplasmas considered as non-EU

The phytoplasmas considered as non-EU (Appendix A) belong to two subcategories:

• Phytoplasmas not known to be present in the EU (‘Ca. P. americanum’, ‘Ca. P. australiense’, ‘Ca. P. fragariae’-related strain (YN-169, YN-10G), and ‘Ca. P. hispanicum’)
• Phytoplasmas known to be present outside the EU and with only limited presence (i.e. reported in only one or few MSs or known to have a restricted distribution) in the EU (‘Ca. P. aurantifolia’-related strains, ‘Ca. P. pruni’-related strains and ‘Ca. P. trifolii’).

These phytoplasmas are categorised in EFSA PLH Panel et al., (2020b), with the exception of ‘Ca. P. australiense’, ‘Ca. P. hispanicum’ and ‘Ca. P. trifolii’, for which a pest categorisation is already available (EFSA PLH Panel et al., 2020a).

Phytoplasmas excluded from further categorisation in the frame of the present mandate

The phytoplasmas excluded from further categorisation in the frame of the present mandate are listed in Appendices B and C. Phytoplasmas listed in Appendix B are originally described or reported from the EU. For the phytoplasmas listed in Appendix C, the ability to infect the host plants is not conclusively supported by the available literature.

Uncertainties

Uncertainties potentially affecting the current list of non-EU potato phytoplasmas include:

• The geographic distribution and prevalence of the phytoplasmas.
• The taxonomy and biological status of poorly characterised phytoplasmas.
• The ability to infect S. tuberosum for some phytoplasmas.

Conclusions

The Panel was requested by the European Commission to produce a categorisation of 133 harmful organisms or groups listed in annexes of Directive 2000/29/EC. One of the groups for which a categorisation was needed is non-EU phytoplasmas of tuber-forming Solanum spp. As a first step, a systematic approach identified 12 phytoplasmas reported to naturally infect S. tuberosum (Annex A).

Among these phytoplasmas, based on information on distribution and prevalence both inside and outside the EU, the Panel identified seven non-EU phytoplasmas, known to occur only outside the EU or having only a limited presence in the EU (Appendix A). These phytoplasmas are categorised in EFSA PLH Panel et al. (2020b), with the exception of ‘Ca. P. australiense’, ‘Ca. P. hispanicum’ and ‘Ca. P. trifolii’, for which a pest categorisation is already available (EFSA PLH Panel et al., 2020a).

The remaining five phytoplasmas (which have a substantial presence in the EU or are originally described or reported from the EU (Appendix B, three phytoplasmas), or whose ability to infect S. tuberosum is not fully confirmed by available literature (Appendix C, two phytoplasmas)) were not categorised within the current mandate. However, the European Commission may request EFSA to categorise some or all the phytoplasmas excluded from the present exercise.

The main uncertainties of this listing concern the taxonomy, geographic distribution and prevalence and the ability to infect S. tuberosum for some phytoplasmas.

Notes:

¹Council Directive 2000/29/EC of 8 May 2000 on protective measures against the introduction into the Community of organisms harmful to plants or plant products and against their spread within the Community. OJ L 169/1, 10.7.2000, p. 1–112.

²Regulation (EU) 2016/2031 of the European Parliament of the Council of 26 October 2016 on protective measures against pests of plants. OJ L 317, 23.11.2016, p. 4–104.

³Regulation (EC) No 178/2002 of the European Parliament and of the Council of 28 January 2002 laying down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety. OJ L 31/1, 1.2.2002, p. 1–24.

Abbreviations

• Ca. P.
• Candidatus Phytoplasma
• CYE
• Clover yellow edge
• EPPO
• European and Mediterranean Plant Protection Organization
• GD
• Global Database
• IRPCM
• International Research Programme on Comparative Mycoplasmology
• MS
• Member State
• PCR
• Polymerase Chain Reaction
• PHS
• Potato hair sprouts
• PHYPAA
• Candidatus Phytoplasma australasia
• PHYPAE
• Candidatus Phytoplasma americanum
• PHYPAS
• Candidatus Phytoplasma asteris
• PHYPAU
• Candidatus Phytoplasma australiense
• PHYPFG
• Candidatus Phytoplasma fragariae
• PHYPMA
• Candidatus Phytoplasma mali
• PHYPTR
• Candidatus Phytoplasma trifolii
• PHYP07
• Candidatus Phytoplasma hispanicum
• PHYP19
• Clover yellow edge phytoplasma
• PHYP74
• Alder yellows phytoplasma
• PLH
• Plant Health
• PPT
• Potato purple top
• RFLP
• Restriction Fragment Length Polymorphism
• TFEU
• Treaty on the Functioning of the European Union
• ToR
• Terms of Reference
• WoS
• Web of Science

Appendix A – Non-EU phytoplasmas of Solanum tuberosum

ID	Phytoplasma name	Related strain name1)	Abbreviation (EPPO code)	16S rRNA	Reasoning for considering non-EU	Uncertainties	References
1	Candidatus Phytoplasma americanum	–	PHYPAE	XVIII	Not reported to be present in the EU	–	Species description: (Lee et al., 2006); S. tuberosum: (EPPO, 2020)
2	Candidatus Phytoplasma aurantifolia	GD32; St_JO_10, 14, 17; PPT-SA; Rus-343F; PPT-GTO29, PPT-GTO30, PPT-SINTV; Potato Huayao Survey 2; Potato hair sprouts, PHS	PHYPAA, PHYP01, PHYP39	II	Italian reports refer to few infected individuals; present in Greece, Portugal; present in EU neighbouring Countries	Cheng et al. (2019) (despite identification of the phytoplasma as belonging to 16SrII by sequencing identity, in silico RFLP, neighbour-joining phylogenetic, in the text it is named as ‘Ca. P. australiense’); Omar et al. (2018), Girsova et al. (2016), Hodgetts et al. (2009), Leyva-Lopez et al. (2002) (unclear subgroup assignation); Paltrinieri and Bertaccini (2007) (12 nested PCR-positive plants over 600 asymptomatic seed potato plants in Italy, no accession numbers available); Parrella et al. (2008) (one batch of 10 Empoasca decipiens in Italy); Tolu et al. (2006) (3 plants from 3 species in Italy); Prota et al. (2007) (less than 20 Myrtus communis plants and possibly in mixed infection in Italy); Granata et al. (2006) (in two Opuntia ficus-indica plants in Italy); Davino et al., 2007 (in one Matthiola incana plant in Italy)	Species description: (White et al., 1998; IRPCM, 2004); Strain descriptions and S. tuberosum: ‘GD32 (Cheng et al., 2019); St_JO_10, 14, 17 (Salem et al., 2019); PPT-SA (Omar et al., 2018); Rus-343F (Girsova et al., 2016); PPT-GTO29, PPT-GTO30, PPT-SINTV (Santos-Cervantes et al., 2010); Potato Huayao Survey 2 (Hodgetts et al., 2009); Potato hair sprouts, PHS (Leyva-Lopez et al., 2002) Solanum tuberosum in Italy (Paltrinieri and Bertaccini, 2007); Empoasca decipiens in Italy (Parrella et al., 2008); Calendula arvensis, Solanum nigrum, and Chenopodium spp. in Italy (Tolu et al., 2006); Matthiola incana in Italy (Davino et al., 2007)
3	Candidatus Phytoplasma australiense	–	PHYPAU	XII-B	Not reported to be present in the EU	–	Species description: (Davis et al., 1997); S. tuberosum: (EPPO, 2020)
4	Candidatus Phytoplasma fragariae	YN-169, YN-10G		XII	Not reported to be present in the EU	Cheng et al., 2015 (several strains ascribed to 16SrXII-I, YN-169, but not identical to each other, plus other 16SrXII strains not assigned to any subgroup, YN-10G)	Species description: (Cheng et al., 2015); S. tuberosum: (Dong et al., 2011; Cheng et al., 2015)
5	Candidatus Phytoplasma hispanicum	–	PHYP07	XIII	Not reported to be present in the EU	Strawberry multiplier disease phytoplasma (STRAWB1) [PHYP75] is classified as RNQP (Annex IV; updated 2019). The phytoplasma is a strain of Ca. P. hispanicum, and the latter is not known to be present in the EU (EFSA PLH Panel et al., 2020a)	Species description: (Davis et al., 2016); S. tuberosum: (Santos-Cervantes et al., 2010)
6	Candidatus Phytoplasma pruni	Clover yellow edge, CYE (Girsova et al., 2016); Potato purple top, AKpot7, MT117, AKpot6 (Davis et al., 2013); Potato purple top, PPT-COAHP, PPT-GTOP (Santos-Cervantes et al., 2010)	PHYP19 (CYE)	III-B (CYE); III-F (AKpot7); III-M(MT117); III-N (AKpot6);III-U (PPT-COAHP, PPT-GTOP)	In the EU reported in four MSs: Czech Republic (two reports), Italy (three reports), Hungary (one report), Lithuania (four reports)	The pest was reported: in eight symptomatic Echinacea purpurea (Franova et al., 2013) and eight Trifolium spp. plants in the Czech Republic (Franova et al., 2004); in less than 50 symptomatic weed samples (Leucanthemum vulgare,Taraxacum officinale and Crepis biennis) (Firrao et al., 1996), in three Prunus spp. (cherry) plants (Paltrinieri et al., 2008) and in an undefined number (few samples) of Asclepias physocarpa plants (Bertaccini et al., 2006) in Italy; in an undefined number of Cirsium arvense and Convolvolus arvensis (Palermo et al., 2004) in Hungary; in two Trifolium spp. plants and in mixed infections (Staniulis et al., 2000), in an undefined number of Gaillardia sp., Dictamnus albus (Samuitien≐ et al., 2007), Heracleum sosnowskyi,Dictamnus albus (Valiunas et al., 2007), Glycine max and Lupinus spp. (Jomantiene et al., 2000), in Lithuania	Species description: (Davis et al., 2013); Strain descriptions and S. tuberosum: CYE (Girsova et al., 2016); AKpot7, MT117, AKpot6 (Davis et al., 2013); PPT-COAHP, PPT-GTOP (Santos-Cervantes et al., 2010); CYE in Lithuania (Staniulis et al., 2000)
7	Candidatus Phytoplasma trifolii	–	PHYPTR	VI-A	Reports from EU MS refer to few infected plants, ranging from 1 to 28	Reports from EU MS refer to few infected plants (Castro and Romero, 2002; Faggioli et al., 2004; Borroto Fernandez et al., 2007; Pribylova et al., 2009; Alfaro-Fernandez et al., 2017; Zambon et al., 2018); unclear subgroup assignation (Girsova et al., 2016)	Species description: (Hiruki and Wang, 2004); S. tuberosum: (EPPO, 2020); Vitis in Italy (Zambon et al., 2018); Centaurea solstitialis in Italy (Faggioli et al., 2004); Amaranthus blitoides and Setaria adhaerens in Spain (Alfaro-Fernandez et al., 2017); Capsicum annuum in Spain (Castro and Romero, 2002); Rhododendron spp. in Czech Republic (Pribylova et al., 2009); Vaccinium myrtillus in Austria (Borroto Fernandez et al., 2007)

¹Reference isolate of ‘Candidatus Phytoplasma species’ is indicated by ‘–’.

Appendix B – Phytoplasmas of Solanum tuberosum excluded from further categorisation as they have substantial presence in the EU or are originally described or reported from the EU

ID	Phytoplasma name	Related strain name1)	Abbreviation (EPPO code)	16S rRNA	EU MS in which the pathogen has been reported	Non-EU European and neighbouring countries	Reasoning for not considering as non-EU	Uncertainties	References
8	Candidatus Phytoplasma asteris	–	PHYPAS	I	Germany, Hungary, Italy (Present widespread); Czech Republic, Spain (Present, restricted distribution); Belgium Denmark, France, Romania (Present, no details); Lithuania; Slovenia2)	Russia (Present, restricted distribution; Belarus (Present, no details); UK2)	Reported in the EU (several MS)	–	Species description: (Lee et al., 2004a); S. tuberosum: (Lee et al., 2006; Arocha et al., 2007; Fahmeed et al., 2009; Hodgetts et al., 2009; Dong et al., 2011; Hosseini et al., 2011; Longoria-Espinoza et al., 2013; Tiwari et al., 2013; Girsova et al., 2016; Castillo Carrillo et al., 2018); S. tuberosum in Italy: (Paltrinieri and Bertaccini, 2007); S. tuberosum in Lithuania (Urbonaite et al., 2016); UK (Jones and Arocha, 2006; Reeder and Arocha, 2008; Nisbet et al., 2014), Slovenia: (Radisek et al., 2009; Romanazzi et al., 2009; Mehle et al., 2018)
9	Candidatus Phytoplasma fragariae	–	PHYPFG	XII-E	Slovenia (EPPO report 2018/085); Belgium2)	UK (EPPO report 2015/031)	Originally described in the EU	-	Species description: (Valiunas et al., 2006)
10	Candidatus Phytoplasma solani	–	PHPSO	XII-A	Italy (Present, widespread); Bulgaria, Croatia, France, Germany, Greece, Hungary, Slovakia, Slovenia, Spain, (Present, restricted distribution); Austria, Czech Republic, Poland (Present, few occurrences); Romania; Belgium2); Portugal2)	Macedonia, Montenegro (Present, widespread); Russia, Serbia, Switzerland, Turkey (Present, restricted distribution); Albania, Armenia, Azerbaijan, Bosnia and Herzegovina, Georgia, Ukraine (Present, no details)	Originally described in the EU (several MS)	–	Species description: (Quaglino et al., 2013); S. tuberosum: (EPPO, 2020); S. tuberosum in Romania: (Lindner et al., 2011)

¹Reference isolate of ‘Candidatus Phytoplasma species’ is indicated by ‘–’.

²Information provided by MS during commenting phase.

Appendix C – Phytoplasmas of Solanum tuberosum excluded from further categorisation as their presence in the species is not fully supported by available literature

ID	Phytoplasma name	Related strain name1)	Abbreviation (EPPO code)	16S rRNA	EU MS in which the pathogen has been reported	Non-EU European and neighbouring countries	Reasoning for not considering as non-EU	Uncertainties	References
11	Candidatus Phytoplasma mali	–	PHYPMA	X	Czech Republic, Germany, Hungary, Italy, Slovakia, Slovenia (Present widespread); Austria, Belgium, Bulgaria, Croatia, Finland, France, Greece, Spain (Present, restricted distribution); Poland, Romania (Present, no details); Lithuania, Netherlands (Present, few occurrences)	Switzerland (Present widespread); Belarus, Norway, Serbia (Present, restricted distribution); Albania, Bosnia and Herzegovina, Moldova, Russia, Turkey, Ukraine (Present, no details)	Originally described in the EU (several MS)	Only one nested PCR positive plant from 600 seed potato asymptomatic plants, probably in mixed infections and no accession number of the isolate available (Paltrinieri and Bertaccini, 2007)	Species description: (Seemuller and Schneider, 2004); S. tuberosum in Italy: (Paltrinieri and Bertaccini, 2007)
12	Unclassified	Potato Colombia M/V	PHYP74	V-C	France	–	Reported in the EU	Only one report from 8 potato plants, 4 in mixed infections with Ca. P. solani; no accession number of the isolate available; taxonomic status uncertain within the 16SrV-C subgroup (Mejia et al., 2011)	Species description: (Lee et al., 2004b); Strain description and S. tuberosum: (Mejia et al., 2011); Alnus in France: (Arnaud et al., 2007)

¹Reference isolate of ‘Candidatus Phytoplasma species’ is indicated by ‘–’.

Annex A – List of phytoplasmas considered in the opinion

See Excel file in Supplementary Information online.