title: An abundant 'CandidatusPhytoplasma solani' tuf b strain is associated with grapevine, stinging nettle andHyalesthes obsoletus.
abstract: Bois noir (BN) associated with 'CandidatusPhytoplasma solani' (Stolbur) is regularly found in Austrian vine growing regions. Investigations between 2003 and 2008 indicated sporadic presence of the confirmed disease vectorHyalesthes obsoletusand frequent infections of bindweed and grapevine. Infections of nettles were rare. In contrast present investigations revealed a mass occurrence ofH. obsoletusalmost exclusively on stinging nettle. The high population densities ofH. obsoletusonUrtica dioicawere accompanied by frequent occurrence of 'Ca.P. solani' in nettles and planthoppers. Sequence analysis of the molecular markerssecY, stamp, tufandvmp1of stolbur revealed a single genotype named CPsM4_At1 in stinging nettles and more than 64 and 90 % abundance in grapevine andH. obsoletus, respectively. Interestingly, this genotype showed tuf b type restriction pattern previously attributed to bindweed associated 'Ca.P. solani' strains, but a different sequence assigned as tuf b2 compared to reference tuf b strains. All other marker genes of CPsM4_At1 clustered with tuf a and nettle derived genotypes verifying distinct nettle phytoplasma genotypes. Transmission experiments withH. obsoletusandAnaceratagallia ribautiresulted in successful transmission of five different strains including the major genotype toCatharanthus roseusand in transmission of the major genotype toU. dioica. Altogether, five nettle and nine bindweed associated genotypes were described. Bindweed types were verified in 34 % of grapevine samples, in few positiveReptalus panzeri, rarely in bindweeds and occasionally inCatharanthus roseusinfected byH. obsoletusorA. ribauti. 'CandidatusPhytoplasma convolvuli' (bindweed yellows) was ascertained in nettle and bindweed samples.
authors.affiliation: Austrian Institute of Technology, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Aryan
authors.affiliation: Austrian Institute of Technology, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Brader
authors.affiliation: Höhere Bundeslehranstalt und Bundesamt für Weinund Obstbau Klosterneuburg, Wienerstraße 74, 3400 Klosterneuburg, Austria.
authors.forename: J
authors.initials: J
authors.lastname: Mörtel
authors.affiliation: Austrian Institute of Technology, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Pastar
authors.affiliation: Höhere Bundeslehranstalt und Bundesamt für Wein- und Obstbau Klosterneuburg, Wienerstraße 74, 3400 Klosterneuburg, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Riedle-Bauer
keywords: Bois noir; Stamp; Stolbur; secY; vmp1; ‘Candidatus phytoplasma convolvuli’