Suchergebnisse

Following a request from the European Commission, the EFSA Panel on Plant Health performed a pest categorisation of Guignardia laricina , a well-de fi ned and distinguishable fungal species of the family Phyllostictaceae. The pathogen is regulated in Council Directive 2000/29/EC (Annex IAI) as a harmful organism whose introduction into the EU is banned. G. laricina is native to East Asia and causes a shoot blight disease of Larix spp. Major hosts of G. laricina are European larch ( Larix decidua ) and two North American larch species ( Larix laricina (tamarack) and Larix occidentalis (Western larch)). Larix kaempferi (Japanese larch) is reported as susceptible. The only other host in nature is Douglas fi r ( Pseudotsuga menziesii) , which is reported as an incidental host, but various other conifers have been reported as susceptible following arti fi cial inoculation, including Picea abies . The fungus is not known to occur in the EU but could enter via plants for planting (including arti fi cially dwarfed plants) and cut branches of Larix spp. It could establish in the EU, as hosts are present and climatic conditions are favourable. The pathogen would be able to spread following establishment by natural dissemination of ascospores and pycnospores and by human movement of infected plants for planting. Should the pathogen be introduced in the EU, impacts can be expected in larch forests, plantations and nurseries, leading to reduced tree growth and ecosystem service provision. The key uncertainties concern the current distribution and level of impacts in the native range of the pathogen. The criteria assessed by the Panel for consideration as a potential quarantine pest are met. As the pest is not present in the EU, not all criteria for consideration as a regulated non-quarantine pest are met.

Following a request from the European Commission, the EFSA Panelon Plant Health performed a pest categorisation of Guignardialaricina, a well-defined and distinguishable fungal species of the family Phyllostictaceae. The pathogen is regulated in Council Directive 2000/29/EC (Annex IAI) as a harmful organism whose introduction into the EU is banned. G.laricina is native to East Asia and causes a shoot blight disease of Larix spp. Major hosts of G.laricina are European larch (Larixdecidua) and two North American larch species (Larixlaricina (tamarack) and Larixoccidentalis (Western larch)). Larixkaempferi (Japanese larch) is reported as susceptible. The only other host in nature is Douglas fir (Pseudotsugamenziesii), which is reported as an incidental host, but various other conifers have been reported as susceptible following artificial inoculation, including Piceaabies. The fungus is not known to occur in the EU but could enter via plants for planting (including artificially dwarfed plants) and cut branches of Larix spp. It could establish in the EU, as hosts are present and climatic conditions are favourable. The pathogen would be able to spread following establishment by natural dissemination of ascospores and pycnospores and by human movement of infected plants for planting. Should the pathogen be introduced in the EU, impacts can be expected in larch forests, plantations and nurseries, leading to reduced tree growth and ecosystem service provision. The key uncertainties concern the current distribution and level of impacts in the native range of the pathogen. The criteria assessed by the Panelfor consideration as a potential quarantine pest are met. As the pest is not present in the EU, not all criteria for consideration as a regulated non-quarantine pest are met.

ABSTRACT Citrus black spot, a fungal disease caused by the quarantine fungus Guignardia citricarpa, restricts the exportation of fresh fruit to countries in the European Union. The occurrence of latent infections and the time required for diagnosis using conventional methods have brought about the need to validate fast, efficient and reproducible molecular techniques to detect the pathogen in asymptomatic tissue. As such, this study aims to detect G. citricarpa in the symptomatic fruit and asymptomatic leaf tissue of sweet oranges by conventional and real-time polymerase chain reaction (PCR). Specificity and limit of detection (LOD) were assessed in tissue samples of fruit lesions and asymptomatic leaves. Low concentrations of the fungus were found in asymptomatic leaves. Under these conditions, real-time PCR proved to be viable, reproducible and highly sensitive to detection of the pathogen.

The Panel conducted a risk assessment of Phyllosticta citricarpa for the EU. P. citricarpa causes citrus black spot (CBS) and is absent from the EU. Under the scenario of absence of specific risk reduction options against P. citricarpa, the risk of entry of P. citricarpa was rated as likely for citrus plants for planting and citrus fruit with leaves, moderately likely for citrus fruit without leaves, unlikely for citrus leaves for cooking and very unlikely for Tahiti lime fruit without leaves. Establishment was rated as moderately likely because susceptible hosts are widely available and environmental conditions in many EU citrus-growing areas are suitable (with high uncertainty) for P. citricarpa ascospore production, dispersal and infection. Current fungicide treatments will not prevent establishment. Environmental favourability is increased by the use of sprinkler and micro-sprinkler irrigation in some EU citrus-growing locations. Spread with trade was rated as moderately likely. Model results indicate that CBS epidemics are most likely to develop in EU citrus-growing areas in late summer to early autumn and in some locations also in late spring to early summer. CBS is expected to affect mainly lemons and late-maturing sweet orange and mandarin varieties, with moderate negative consequences for the production of fresh fruit, but with environmental impact of additional fungicide treatments. Negative consequences would be minor for early-maturing citrus varieties and minimal for citrus for processing. Uncertainty concerning the consequences is high, mainly because of the lack of data on critical climate response parameters for the pathogen but also because information on impact in areas at the limits of the current distribution is scarce. Since eradication and containment are difficult, phytosanitary measures should focus on preventing entry. Current phytosanitary measures are evaluated to be effective, with the exception of pest-free production sites.

The genus Phyllosticta occurs worldwide, and contains numerous plant pathogenic, endophytic and saprobic species. Phyllosticta citricarpa is the causal agent of Citrus Black Spot disease (CBS), affecting fruits and leaves of several citrus hosts (Rutaceae), and can also be isolated from asymptomatic citrus tissues. Citrus Black Spot occurs in citrus-growing regions with warm summer rainfall climates, but is absent in countries of the European Union (EU). Phyllosticta capitalensis is morphologically similar to P. citricarpa, but is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts, and is known to occur in Europe. To determine which Phyllosticta spp. occur within citrus growing regions of EU countries, several surveys were conducted (2015–2017) in the major citrus production areas of Greece, Italy, Malta, Portugal and Spain to collect both living plant material and leaf litter in commercial nurseries, orchards, gardens, backyards and plant collections. A total of 64 Phyllosticta isolates were obtained from citrus in Europe, of which 52 were included in a multi-locus (ITS, actA, tef1, gapdh, LSU and rpb2 genes) DNA dataset. Two isolates from Florida (USA), three isolates from China, and several reference strains from Australia, South Africa and South America were included in the overall 99 isolate dataset. Based on the data obtained, two known species were identified, namely P. capitalensis (from asymptomatic living leaves of Citrus spp.) in Greece, Italy, Malta, Portugal and Spain, and P. citricarpa (from leaf litter of C. sinensis and C. limon) in Italy, Malta and Portugal. Moreover, two new species were described, namely P. paracapitalensis (from asymptomatic living leaves of Citrus spp.) in Italy and Spain, and P. paracitricarpa (from leaf litter of C. limon) in Greece. On a genotypic level, isolates of P. citricarpa populations from Italy and Malta (MAT1-2-1) represented a single clone, and those from Portugal (MAT1-1-1) another. Isolates of P. citricarpa and P. paracitricarpa were able to induce atypical lesions (necrosis) in artificially inoculated mature sweet orange fruit, while P. capitalensis and P. paracapitalensis induced no lesions. The Phyllosticta species recovered were not found to be widespread, and were not associated with disease symptoms, indicating that the fungi persisted over time, but did not cause disease.

We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and is subject to phytosanitary legislation in the EU. This species is frequently confused with a taxon generally referred to as G. mangiferae, the presumed teleomorph of P. capitalensis, which is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts. DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S nrDNA, ITS2) and partial translation elongation factor 1-alpha (TEF1), actin and glyceraldehyde-3-phosphate dehydrogenase (GPDH) genes resolved nine clades correlating to seven known, and two apparently undescribed species. Phyllosticta citribraziliensis is newly described as an endophytic species occurring on Citrus in Brazil. An epitype is designated for P. citricarpa from material newly collected in Australia, which is distinct from P. citriasiana, presently only known on C. maxima from Asia. Phyllosticta bifrenariae is newly described for a species causing leaf and bulb spots on Bifrenaria harrisoniae (Orchidaceae) in Brazil. It is morphologically distinct from P. capitalensis, which was originally described from Stanhopea (Orchidaceae) in Brazil; an epitype is designated here. Guignardia mangiferae, which was originally described from Mangifera indica (Anacardiaceae) in India, is distinguished from the non-pathogenic endophyte, P. brazilianiae sp. nov., which is common on M. indica in Brazil. Furthermore, a combined phylogenetic tree revealed the P. capitalensis s.l. clade to be genetically distinct from the reference isolate of G. mangiferae. Several names are available for this clade, the oldest being P. capitalensis. These results suggest that endophytic, non-pathogenic isolates occurring on a wide host range would be more correctly referred to as P. capitalensis. However, more genes need to be analysed to fully resolve the morphological variation still observed within this clade. ; We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and is subject to phytosanitary legislation in the EU. This species is frequently confused with a taxon generally referred to as G. mangiferae, the presumed teleomorph of P. capitalensis, which is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts. DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S nrDNA, ITS2) and partial translation elongation factor 1-alpha (TEF1), actin and glyceraldehyde-3-phosphate dehydrogenase (GPDH) genes resolved nine clades correlating to seven known, and two apparently undescribed species. Phyllosticta citribraziliensis is newly described as an endophytic species occurring on Citrus in Brazil. An epitype is designated for P. citricarpa from material newly collected in Australia, which is distinct from P. citriasiana, presently only known on C. maxima from Asia. Phyllosticta bifrenariae is newly described for a species causing leaf and bulb spots on Bifrenaria harrisoniae (Orchidaceae) in Brazil. It is morphologically distinct from P. capitalensis, which was originally described from Stanhopea (Orchidaceae) in Brazil; an epitype is designated here. Guignardia mangiferae, which was originally described from Mangifera indica (Anacardiaceae) in India, is distinguished from the non-pathogenic endophyte, P. brazilianiae sp. nov., which is common on M. indica in Brazil. Furthermore, a combined phylogenetic tree revealed the P. capitalensis s.l. clade to be genetically distinct from the reference isolate of G. mangiferae. Several names are available for this clade, the oldest being P. capitalensis. These results suggest that endophytic, non-pathogenic isolates occurring on a wide host range would be more correctly referred to as P. capitalensis. However, more genes need to be analysed to fully resolve the morphological variation still observed within this clade.

We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and is subject to phytosanitary legislation in the EU. This species is frequently confused with a taxon generally referred to as G. mangiferae, the presumed teleomorph of P. capitalensis, which is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts. DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S nrDNA, ITS2) and partial translation elongation factor 1-alpha (TEF1), actin and glyceraldehyde-3-phosphate dehydrogenase (GPDH) genes resolved nine clades correlating to seven known, and two apparently undescribed species. Phyllosticta citribraziliensis is newly described as an endophytic species occurring on Citrus in Brazil. An epitype is designated for P. citricarpa from material newly collected in Australia, which is distinct from P. citriasiana, presently only known on C. maxima from Asia. Phyllosticta bifrenariae is newly described for a species causing leaf and bulb spots on Bifrenaria harrisoniae (Orchidaceae) in Brazil. It is morphologically distinct from P. capitalensis, which was originally described from Stanhopea (Orchidaceae) in Brazil; an epitype is designated here. Guignardia mangiferae, which was originally described from Mangifera indica (Anacardiaceae) in India, is distinguished from the non-pathogenic endophyte, P. brazilianiae sp. nov., which is common on M. indica in Brazil. Furthermore, a combined phylogenetic tree revealed the P. capitalensis s.l. clade to be genetically distinct from the reference isolate of G. mangiferae. Several names are available for this clade, the oldest being P. capitalensis. These results suggest that endophytic, non-pathogenic isolates occurring on a wide host range would be more correctly referred to as P. capitalensis. However, more genes need to be analysed to fully resolve the morphological variation still observed within this clade. ; We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and is subject to phytosanitary legislation in the EU. This species is frequently confused with a taxon generally referred to as G. mangiferae, the presumed teleomorph of P. capitalensis, which is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts. DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S nrDNA, ITS2) and partial translation elongation factor 1-alpha (TEF1), actin and glyceraldehyde-3-phosphate dehydrogenase (GPDH) genes resolved nine clades correlating to seven known, and two apparently undescribed species. Phyllosticta citribraziliensis is newly described as an endophytic species occurring on Citrus in Brazil. An epitype is designated for P. citricarpa from material newly collected in Australia, which is distinct from P. citriasiana, presently only known on C. maxima from Asia. Phyllosticta bifrenariae is newly described for a species causing leaf and bulb spots on Bifrenaria harrisoniae (Orchidaceae) in Brazil. It is morphologically distinct from P. capitalensis, which was originally described from Stanhopea (Orchidaceae) in Brazil; an epitype is designated here. Guignardia mangiferae, which was originally described from Mangifera indica (Anacardiaceae) in India, is distinguished from the non-pathogenic endophyte, P. brazilianiae sp. nov., which is common on M. indica in Brazil. Furthermore, a combined phylogenetic tree revealed the P. capitalensis s.l. clade to be genetically distinct from the reference isolate of G. mangiferae. Several names are available for this clade, the oldest being P. capitalensis. These results suggest that endophytic, non-pathogenic isolates occurring on a wide host range would be more correctly referred to as P. capitalensis. However, more genes need to be analysed to fully resolve the morphological variation still observed within this clade.

We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and is subject to phytosanitary legislation in the EU. This species is frequently confused with a taxon generally referred to as G. mangiferae, the presumed teleomorph of P. capitalensis, which is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts. DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S nrDNA, ITS2) and partial translation elongation factor 1-alpha (TEF1), actin and glyceraldehyde-3-phosphate dehydrogenase (GPDH) genes resolved nine clades correlating to seven known, and two apparently undescribed species. Phyllosticta citribraziliensis is newly described as an endophytic species occurring on Citrus in Brazil. An epitype is designated for P. citricarpa from material newly collected in Australia, which is distinct from P. citriasiana, presently only known on C. maxima from Asia. Phyllosticta bifrenariae is newly described for a species causing leaf and bulb spots on Bifrenaria harrisoniae (Orchidaceae) in Brazil. It is morphologically distinct from P. capitalensis, which was originally described from Stanhopea (Orchidaceae) in Brazil; an epitype is designated here. Guignardia mangiferae, which was originally described from Mangifera indica (Anacardiaceae) in India, is distinguished from the non-pathogenic endophyte, P. brazilianiae sp. nov., which is common on M. indica in Brazil. Furthermore, a combined phylogenetic tree revealed the P. capitalensis s.l. clade to be genetically distinct from the reference isolate of G. mangiferae. Several names are available for this clade, the oldest being P. capitalensis. These results suggest that endophytic, non-pathogenic isolates occurring on a wide host range would be more correctly ...

The genus Phyllosticta occurs worldwide, and contains numerous plant pathogenic, endophytic and saprobic species. Phyllosticta citricarpa is the causal agent of Citrus Black Spot disease (CBS), affecting fruits and leaves of several citrus hosts (Rutaceae), and can also be isolated from asymptomatic citrus tissues. Citrus Black Spot occurs in citrus-growing regions with warm summer rainfall climates, but is absent in countries of the European Union (EU). Phyllosticta capitalensis is morphologically similar to P. citricarpa, but is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts, and is known to occur in Europe. To determine which Phyllosticta spp. occur within citrus growing regions of EU countries, several surveys were conducted (2015–2017) in the major citrus production areas of Greece, Italy, Malta, Portugal and Spain to collect both living plant material and leaf litter in commercial nurseries, orchards, gardens, backyards and plant collections. A total of 64 Phyllosticta isolates were obtained from citrus in Europe, of which 52 were included in a multi-locus (ITS, actA, tef1, gapdh, LSU and rpb2 genes) DNA dataset. Two isolates from Florida (USA), three isolates from China, and several reference strains from Australia, South Africa and South America were included in the overall 99 isolate dataset. Based on the data obtained, two known species were identified, namely P. capitalensis (from asymptomatic living leaves of Citrus spp.) in Greece, Italy, Malta, Portugal and Spain, and P. citricarpa (from leaf litter of C. sinensis and C. limon) in Italy, Malta and Portugal. Moreover, two new species were described, namely P. paracapitalensis (from asymptomatic living leaves of Citrus spp.) in Italy and Spain, and P. paracitricarpa (from leaf litter of C. limon) in Greece. On a genotypic level, isolates of P. citricarpa populations from Italy and Malta (MAT1-2-1) represented a single clone, and those from Portugal (MAT1-1- 1) another. Isolates of P. ...

Following a request from the European Commission, the EFSA Panel on Plant Health (EFSA PLH Panel) was asked to react to a document entitled "Comments on the European Union Food Safety Authority's Pest Risk Assessment for Phyllosticta citricarpa", authored by Hattingh et al., which was posted online in August 2014 on the website of Citrus Research International (Pty) Ltd, South Africa. Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa (McAlpine) Van der Aa, is a fruit-blemishing and leaf-spotting disease affecting citrus. P. citricarpa is not known to occur in the EU territory and is regulated as a quarantine organism in citrus (Council Directive 2000/29/EC). The Panel assessed the comments by Hattingh et al. in the light of the content of the EFSA PLH Panel Scientific Opinion on CBS and the EFSA report detailing responses to comments received during the public consultation on the draft opinion. The Panel stands by the EFSA PLH Panel Scientific Opinion on CBS and considers that the comments by Hattingh et al. have been thoroughly addressed in the EFSA report on the public consultation on the EFSA PLH Panel Scientific Opinion on CBS. A detailed point by point reply to the comments by Hattingh et al. is provided in an Appendix of this Panel statement. Since September 2014, EFSA has written to the lead author of the comments trying to engage in a scientific dialogue concerning the sources of uncertainty related to the risks posed by P. citricarpa to plant health in the EU, so as to identify ways to reduce such uncertainties (e.g. with further research and/or data exchange). The EFSA PLH Panel also remains open to such constructive dialogue in the future.

Following a request from the European Commission, the EFSA Panel on Plant Health (PLH) was asked to assess two publications, authored by Magarey et al. and Martınez-Minaya et al. from 2015, with regard to a need to update the EFSA Scientific Opinion from 2014 on the risk of Phyllosticta citricarpa (Guignardia citricarpa) for the EU territory. The EFSA PLH Panel was also requested to assess any other relevant scientific information published after the finalisation of the EFSA Scientific Opinion. The fungus P. citricarpa (McAlpine) Van der Aa causes the citrus disease citrus black spot (CBS), and is regulated as quarantine organism in Council Directive 2000/29/EC. The Panel assessed the two publications in detail as well as all relevant publications published until 31 March 2016. A comparison with the EFSA PLH Panel (2014) was made, survey data on CBS from South Africa used in Magarey et al. (2015) were evaluated, and the citrus production areas in the EU were characterised and compared with results from Magarey et al. (2015). Uncertainty and model sensitivity were discussed. It was concluded that the evidence presented in Magarey et al. from 2015 does not require an updating of EFSA PLH Panel (2014). The conclusion in the Opinion that probability of CBS establishment in the EU is moderately likely is not affected by the paper by Magarey et al. (2015) predicting establishment in some of the EU locations they selected. The high level of uncertainty regarding the probability of establishment is also unchanged by Magarey et al. (2015). The Panel concluded that Martınez-Minaya et al. (2015) does not provide new evidence requiring an update to EFSA PLH Panel (2014), principally because it had already been concluded that global climate zones are based on factors and thresholds that are broad and not necessarily representative of those that are critical for the pathogen and its host.