Title

Occurrence of Stolbur phytoplasma in the vector Hyalesthes obsoletus, herbaceous host plants and grapevine in South Tyrol

Document Type

Article

Journal or Conference Title

Vitis

ISSN

0042-7500

Volume

48

Issue

4

First Page

185

Last Page

192

Publication Date

2009

Department

Natural Sciences and Mathematics

Abstract

Bois noir (BN) is a grapevine yellows disease caused by a phytoplasma of the Stolbur group (16SrXII-A). The planthopper Hyalesthes obsoletus is known to be the principal vector and can accidentally transmit the phytoplasma from its herbaceous host plants to grapevine (Vitis vinifera). Due to the increasing incidence of BN over the last decade, a monitoring study was conducted in South Tyrol (Northern Italy). Over a period of up to four years, 659 insect vector samples, 516 herbaceous plants of 41 potential host plant species as well as 56 grapevine samples from BN-affected vineyards were tested for the presence of the Stolbur phytoplasma using a nested PCR procedure. In addition, a recently developed TaqMan allelic discrimination assay was employed to determine different subtypes of BN in infected samples. The Stolbur phytoplasma could be detected in all three sample types analysed, and was shown to belong to two different subtypes, VK type I and VK type II. In most vineyards one subtype was found to be predominant. The average infection rate of H. obsoletus amounted to 24.1 %. Analysis of herbaceous plants revealed that 25.1 % of the Convolvulus arvensis samples tested positive for the BN phytoplasma, as well as 4.5 %,, of the Urtica dioica samples. Taken together, our results underline the role of these two species commonly found in the undergrowth vegetation of South Tyrolean vineyards as an important reservoir of the Stolbur phytoplasma.

Rights

Copyright © 2009 Institut Fuer Rebenzuechtung Geilweilerhof der. All rights reserved.

Publisher Statement

Originally published as Berger, J., Schweigkofler, W., Kerschbamer, C., Roschatt, C., Dalla Vía, J., & Baric, S. (2015). Occurrence of Stolbur phytoplasma in the vector Hyalesthes obsoletus, herbaceous host plants and grapevine in South Tyrol (Northern Italy). VITIS-Journal of Grapevine Research, 48(4), 185.