Detection of the German grapevine yellows (Vergilbungskrankheit) MLO in grapevine, alternative hosts and a vector by a specific PCR procedure

Abstract

A polymerase chain reaction procedure was developed which enables specific amplification of a ribosomal sequence from the mycoplasmalike organism (MLO) associated with German grapevine yellows (Vergilbungskrankheit, VK) and stolbur-related diseases of solanaceous plants. Successful amplification from all samples prepared from various cultivars collected in different viticultural areas indicates that the causal agent is a relatively homogeneous organism. Amplification was also achieved with template DNA prepared from naturally infected weeds in vineyards such as Convolvolus arvensis and Solanum nigrum, and from the planthopper Hyalesthes obsoletus that was collected in the vineyards. Feeding of insects of this species on grapevine seedlings resulted in the development of typical yellows symptoms by the grapes. H. obsoletus could therefore be identified as a vector of Vergilbungskrankheit.Abbreviations: FD = Flavescence dor6e; GY --Grapevine yellows; MLO --Mycoplasmalike organism; PCR --Polymerase chain reaction; RFLP -restriction fragment length polymorphism; VK --Vergilbungskrankheit (German grapevine yellows).

Classification of phytoplasma strains in the elm yellows group (16SrV) and proposal of ‘Candidatus Phytoplasma ulmi’ for the phytoplasma associated with elm yellows

“…On the basis of an analysis of the FD9 DNA sequence, the German ALY strain 882 (subgroup rp-K) was very similar to grapevine yellows phytoplasma (Palatinate grapevine yellows) strains that were reported to cross-infect black alder and grapevine in Germany (Angelini et al, 2001). Phytoplasma strains that are associated with grapevine yellows disease in grapevine in Germany are transmitted by the alder-feeding Oncopsis alni and cannot be transmitted by Scaphoideus titanus, the vector of FD phytoplasma strains associated with FD in France and Italy (Maixner et al, 1995). Members of subgroup 16SrV-A, which are associated with Ulmus spp., and subgroup 16SrV-E, which are associated with Rubus spp., represented two rather homogeneous strain clusters, based on phylogenetic analyses of both 16S rRNA and ribosomal protein genes.…”

Multilocus sequence analysis reveals the genetic diversity of European fruit tree phytoplasmas and supports the existence of inter-species recombination

“…Nucleic acids were extracted from plants and insects as described by Maixner et al (1995). The aceF, pnp, secY and imp genes were amplified by nested PCR using the primers described in Table 2.…”

First report of Candidatus Phytoplasma aurantifolia (16SrII group) associated with Conocarpus erectus disease in Iran

“…The samples were powdered in the mortar containing liquid nitrogen and stored in the −20°C freezer. Genomic DNA was extracted from~100 mg of powdered tissues using a CTAB-based method as described by Maixner et al (1995) with minor modifications. The lysates obtained from each sample were extracted two times by phenol: chloroform:isoamyl alcohol and chloroform:isoamyl alcohol, respectively.…”