Abstract
A European quarantine organism ‘Candidatus Phytoplasma pyri’ causing devastating pear decline disease has been reported to affect pear trees in several European countries. In this study a multilocus sequence analysis was successfully used to gain detailed insight into the molecular diversity of thirty closely related ‘Candidatus Phytoplasma pyri’ isolates from different orchards in Slovenia. Among three genomic regions analyzed, the 16S/23S rRNA intergenic spacer region was the most conserved among Slovenian isolates with 99.7 % sequence identity, yielding only three distinct genotypes. On the other hand, five different genotypes were detected when analyzing secY and aceF genomic regions that shared sequence identity of 94.8 and 97.2 %, respectively. Six of the detected genotypes, specifically four in the secY region and one in each of the two other analyzed genomic regions, were unique for Slovenia. At least eight different haplotypes were found with multilocus sequence analysis, indicating high molecular diversity among Slovenian ‘Ca. P. pyri’ isolates. Haplotypes were clustered into two major clusters, separated by at least 45 mutations. No connection was established between haplotype occurrence and cultivar type.
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Acknowledgments
This work was supported by the Slovenian Research Agency grant P4-0165. The authors thank phytosanitary inspectors for providing the samples and Dr. Elizabeth Covington for critical reading of the manuscript.
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Jernej, P., Nataša, M., Petra, N. et al. Molecular diversity of ‘Candidatus Phytoplasma pyri’ isolates in Slovenia. Eur J Plant Pathol 139, 801–809 (2014). https://doi.org/10.1007/s10658-014-0434-5
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DOI: https://doi.org/10.1007/s10658-014-0434-5