title: 'Candidatus Phytoplasma convolvuli', a new phytoplasma taxon associated with bindweed yellows in four European countries.
abstract: Plants of Convolvulus arvensis exhibiting symptoms of undersized leaves, shoot proliferation and yellowing, collectively defined as bindweed yellows, were sampled in different regions of Europe and assessed for phytoplasma infection by PCR amplification using phytoplasma universal rRNA operon primer pairs. Positive results were obtained for all diseased plants. RFLP analysis of amplicons comprising the16S rRNA gene alone or the16S rRNA gene and 16-23S intergenic spacer region indicated that the detected phytoplasmas were distinguishable from all other previously described rRNA gene sequences. Analysis of 16S rRNA gene sequences derived from seven selected phytoplasma strains (BY-S57/11, BY-S62/11, BY-I1015, BY-I1016, BY-BH1, BY-BH2 and BY-G) showed that they were nearly identical (99.9-100% gene sequence similarity) but shared less than 97.5% similarity with comparable sequences of other phytoplasmas. Thus, BY phytoplasmas represent a new taxon whose closest relatives are stolbur phytoplasma strains and 'Candidatus Phytoplasma fragariae' with which they share 97.2% and 97.1% 16S rRNA gene sequence similarity, respectively. Phylogenetic analysis of 16S rRNA gene sequences confirmed that bindweed yellows phytoplasma strains collectively represent a distinct lineage within the phytoplasma clade and share a common ancestor with previously published or proposed 'Candidatus Phytoplasma' taxa within a major branch including aster yellows and stolbur phytoplasmas. On the basis of unique 16S rRNA gene sequences and biological properties that include a single host plant species and a geographical distribution limited to parts of Europe, the bindweed yellows (BY) phytoplasmas represent a coherent but discrete taxon, 'Candidatus Phytoplasma convolvuli', with strain BY-S57/11 (GenBank accession no. JN833705) as the reference strain.
authors.affiliation: Department of Agriculture and Environmental Sciences, University of Udine, 33100 Udine, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Martini
authors.affiliation: Department of Pharmaceutical and Biomedical Sciences, University of Salerno, 84084 Fisciano (SA), Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Marcone
authors.affiliation: Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Mitrović
authors.affiliation: Julius Kühn-Institute, Federal Research Institute for Cultivated Plants, Institute for Plant Protection in Fruit Crops and Viticulture, 54470 Bernkastel-Kues, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Maixner
authors.affiliation: University of Banjaluka, Faculty of Agriculture, 7800 Banjaluka, Bosnia and Herzegovina.
authors.forename: Duška
authors.initials: D
authors.lastname: Delić
authors.affiliation: Certis Europe B.V., 21047 Saronno (VA), Italy.
authors.forename: Arben
authors.initials: A
authors.lastname: Myrta
authors.affiliation: Department of Agriculture and Environmental Sciences, University of Udine, 33100 Udine, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Ermacora
authors.affiliation: Department of Agricultural Sciences (DipSA), Plant Pathology, Alma Mater Studiorum University of Bologna, Bologna, 40127, Italy.
authors.forename: Assunta
authors.initials: A
authors.lastname: Bertaccini
authors.affiliation: Institute of Pesticides and Environmental Protection, 11080 Belgrade, Serbia.
authors.forename: Bojan
authors.initials: B
authors.lastname: Duduk
mesh_terms: D015373:Bacterial Typing Techniques; D031254:Convolvulus / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D005060:Europe; D008969:Molecular Sequence Data; D010802:Phylogeny; D045582:Phytoplasma / Q000145:classification* / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S