A survey of ‘Candidatus Phytoplasma pyri’ isolates in the Czech Republic based on imp gene genotyping


  • Lucie VALENTOVÁ Research and Breeding Institute of Pomology Holovousy Ltd. (CZ)
  • Markéta BOHUNICKÁ University of Hradec Králové, Department of Biology, Faculty of Science (CZ)
  • Martina REJLOVÁ Research and Breeding Institute of Pomology Holovousy Ltd. (CZ)
  • Jana SUCHÁ Central Institute for Supervising and Testing in Agriculture (CZ)
  • Tomáš NEČAS Mendel University in Brno, Faculty of Horticulture, Department of Pomology (CZ)
  • Aleš EICHMEIER Mendel University in Brno, Faculty of Horticulture (CZ)
  • Jana CMEJLOVA Research and Breeding Institute of Pomology Holovousy Ltd., Laboratory for Molecular Biology (CZ)
  • Radek CMEJLA Research and Breeding Institute of Pomology Holovousy Ltd., Laboratory for Molecular Biology (CZ)




16SrX group phytoplasma, genetic variability, immunodominant membrane protein, pear decline symptoms


Candidatus Phytoplasma spp.’ are pathogenic bacteria that infect many plant species. ‘Candidatus Phytoplasma pyri’, one of the members of the 16SrX group causes pear decline disease that adversely affects pear crops. To describe the prevalence of ‘Ca. P. pyri’ genotypes in the Czech Republic, 143 pear samples were collected from 41 locations including commercial orchards as well as trees along roads. Phytoplasma was detected by PCR in 115 samples, and it was possible to determine imp gene genotype in 84 samples. The most frequent genotypes were A1, B1, and C, which were identified in 71% of phytoplasma positive samples. ‘Ca. P. pyri’ was present either alone or as a mix of two populations in 88% of genotyped samples, and in another 6% of samples it was found in a mixed infection with ‘Ca. Phytoplasma mali’. A sole infection with ‘Ca. Phytoplasma mali’ was observed in 6% of samples. As for symptoms, 19% of symptomatic samples were found to be phytoplasma negative, and 74% of asymptomatic samples proved to be phytoplasma positive; leaf roll was more often observed in phytoplasma positive samples, while leaf narrowing rather indicated the absence of phytoplasma. The mildest symptoms were observed in samples infected with ‘Ca. P. pyri’ of the A1 imp genotype.


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How to Cite

VALENTOVÁ, L., BOHUNICKÁ, M., REJLOVÁ, M., SUCHÁ, J., NEČAS, T., EICHMEIER, A., CMEJLOVA, J., & CMEJLA, R. (2022). A survey of ‘Candidatus Phytoplasma pyri’ isolates in the Czech Republic based on imp gene genotyping. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 50(1), 12602. https://doi.org/10.15835/nbha50112602



Research Articles
DOI: 10.15835/nbha50112602