EPPO Bulletin

AbstractPistachio (Pistacia vera L.) is a vital crop for Türkiye's economy, occupying over 420 000 ha, primarily in south‐eastern Anatolia. In 2023, severe symptoms, such as curling, chlorosis and needle‐like leaf deformation, were observed on pistachio trees in Şanlıurfa Province. This prompted a molecular study of phytoplasma pathogens. A real‐time PCR targeting the 16SrDNA gene was used to analyse DNA from eight symptomatic and two asymptomatic trees. A phytoplasma was found in two symptomatic samples but not in asymptomatic controls. Positive samples were further analysed using nested PCR. One sequence with 99% identity to ‘Candidatus Phytoplasma trifolii’ (16SrVI‐A subgroup) was found by bidirectional sequencing of PCR products. The identification of the phytoplasma was confirmed by a phylogenetic analysis showing the clustering of the UP 1 isolate with ‘Ca. Phytoplasma trifolii’ reference strain and by a virtual RFLP analysis using 17 restrictions enzymes. This first report of ‘Ca. Phytoplasma trifolii’ in pistachio in Türkiye highlights the presence of this phytoplasma in a key agricultural sector. Although no yield losses have been observed to date, broader surveys and monitoring of leafhopper vectors are necessary to assess the potential risk and implement timely management strategies.

Specific scopeThis Standard describes a diagnostic protocol for ‘Candidatus Phytoplasma phoenicium’.This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols. 1Specific approval and amendmentApproved in 2021–06.

Specific scopeThis Standard describes a diagnostic protocol for ‘Candidatus Liberibacter africanus’, ‘Candidatus Liberibacter americanus’ and ‘Candidatus Liberibacter asiaticus’.1This Standard should be used in conjunction with PM 7/76 (5) Use of EPPO diagnostic protocols.Specific approval and amendmentFirst approved in 2014–09. Revised in 2021–04.

Specific scopeThis Standard describes a national regulatory control system for the bacterial pathogen ‘Candidatus Liberibacter solanacearum’ and its vector Bactericera cockerelli when regulated as quarantine pests. It also covers measures to reduce the risk of ‘Ca. L. solanacearum’ spreading to potato production systems when listed as a regulated nonquarantine pest (RNQP) on seed potatoFor the EPPO A1 listed pests recommended for regulation as quarantine pests B. cockerelli and ‘Ca. L. solanacearum’ (Solanaceae haplotypes, i.e. non‐European haplotypes, such as haplotypes A and B), the Standard describes measures to achieve: Exclusion from the EPPO region of B. cockerelli, which is an efficient vector of ‘Ca. L. solanacearum’ within solanaceous crops (e.g. potato, tomato) Eradication of incursions of B. cockerelli Exclusion from the EPPO region of non‐European haplotypes of ‘Ca. L. solanacearum’ Eradication of incursions of non‐European haplotypes of ‘Ca. L. solanacearum’. Although reference will only be made to the non‐European haplotypes A and B, the Standard would also apply to new non‐European haplotypes of ‘Ca. L. solanacearum’ which may have different host ranges or which may be vectored more efficiently by psyllids which are widespread in the region.For the haplotypes which are not recommended for regulation as quarantine pests but are recommended for regulation as RNQPs on seed potato (i.e. European haplotypes, such as C, D and E), the Standard describes measures (specified in Appendix 4) to reduce the risk of spread to potato production systems to achieve: Exclusion of European haplotypes of ‘Ca. L. solanacearum’ from the potato production system Suppression of European haplotypes of ‘Ca. L. solanacearum’ in potato production systems where they are present. Although reference will only be made to haplotypes C, D and E, Appendix 4 would also apply to new European haplotypes of ‘Ca. L. solanacearum’.SpecificapprovalFirst approved in 2017‐09. Revised in 2020‐09.

Specific scopeThis Standard describes a diagnostic protocol for ‘Candidatus Phytoplasma mali’, ‘Ca. P. pyri’ and ‘Ca. P. prunorum’.This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocolsSpecific approval and amendmentApproved as PM 7/62 Candidatus Phytoplasma mali and PM 7/63 Ca. P. pyri in 2006. First revision in 2017‐02 as a single Standard as PM 7/62 (2) with the addition of ‘Ca. P. prunorum’. Second revision in 2019‐06.

ScopeThis Standard describes procedures for official control with the aim of detecting, containing and eradicating those ‘Candidatus Liberibacter’ species which are causal agents of Huanglongbing (also known as citrus greening disease) and their vectors Trioza erytreae and Diaphorina citri. NPPOs may draw on this guidance when developing national contingency plans for outbreaks of ‘Candidatus Liberibacter’ species and their vectors.Approval and amendmentFirst approved in 2019‐09.

Specific scopeThis Standard describes the procedures for inspection of places of production of plants for planting which are susceptible to ‘Candidatus Phytoplasma pyri’. The scope of a place of production inspection may be for export, for internal country movements of materials or as an element of a national survey. Further inspections would be needed to determine freedom of a country or area from the pest concerned. This Standard does not cover eradication or containment measures in infested areas or measures needed to establish and maintain pest‐free places of production within areas where the pest is known to occur. It provides more detailed guidance to supplement EPPO Standard PM 3/76 (1) Trees of Malus, Pyrus, Cydonia and Prunus spp. – inspection of places of production.

Specific scopeThis Standard describes a national regulatory control system for Bactericera cockerelli and the bacterial pathogen ‘Candidatus Liberibacter solanacearum’ the cause of zebra chip disease in potato. The scope is as follows: Exclusion from the EPPO region of B. cockerelli an efficient vector of ‘Ca. L. solanacearum’ within solanaceous crops (e.g. potato, tomato) Eradication of incursions of B. cockerelli Exclusion from the EPPO region of ‘Ca. L. solanacearum’ haplotypes A and B. Although reference will only be made to haplotypes A and B, the Standard would also apply to new non‐European haplotypes of ‘Ca. L. solanacearum’ which may have different host ranges, or which may be vectored more efficiently by psyllids which are widespread in the region. The reduction of the risk of spreading ‘Ca. L. solanacearum’ haplotypes C, D and E to potato production systems and potatoes being moved within the EPPO region may be recommended in future when more information is available but is not covered in this Standard.Specific approvalFirst approved in 2017‐09.