Widespread occurrence of 'Candidatus Phytoplasma ulmi' in elm species in Germany.
BMC Microbiol
; 20(1): 74, 2020 03 31.
Article
em En
| MEDLINE
| ID: mdl-32234008
ABSTRACT
BACKGROUND:
'Candidatus Phytoplasma ulmi' is the agent associated with elm yellows and has been categorised in the European Union as a quarantine pathogen. For central and northern European countries, information on the occurrence and distribution of the pathogen and its impact on elms is scarce, so a survey of native elm trees has been conducted in Germany.RESULTS:
About 6500 samples from Ulmus minor, Ulmus laevis and Ulmus glabra, were collected nationwide. Phytoplasma detection was performed by applying a universal 16Sr DNA-based quantitative PCR (qPCR) assay and a novel 'Ca. P. ulmi' specific qPCR assay targeting the 16S-23S spacer region. Both assays revealed that 28% of the samples were infected by 'Ca. P. ulmi', but infection rates of the elm species and regional incidences differed. The phytoplasma presence in the trees was not correlated to disease-specific symptoms. The survey identified a regional disparity of infection which was high in east, south and central Germany, whereas only a few infected sites were found in the western and northern parts of the country. Monitoring the seasonal titre of 'Ca. P. ulmi' in an infected tree by qPCR revealed a high colonisation in all parts of the tree throughout the year.CONCLUSIONS:
'Ca. P. ulmi' is widely present in elms in Germany. The rare occurrence of symptoms indicates either a high degree of tolerance in elm populations or a low virulence of pathogen strains enabling high infection rates in a long-living host.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Doenças das Plantas
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RNA Ribossômico 16S
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Ulmus
/
Phytoplasma
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article