Huanglongbing (HLB) is a severe citrus (Citrus spp.) disease associated with the bacteria genus Candidatus Liberibacter, detected in Brazil in 2004. Another bacterium was found in association with HLB symptoms and characterized as a phytoplasma belonging to the 16SrIX group. The objectives of this study were to identify potential leafhopper vectors of the HLB-associated phytoplasma and their ho...

Phytoplasmas are uncultivable prokaryotic wall-less pathogens belonging to the class Mollicutes that inhabit plant phloem and insects. Their identification and classification is difficult and mainly based on the polymorphism of their 16S rRNAgene sequences. Aster yellows (AY; 'Candidatus Phytoplasma asteris') phytoplasmas (ribosomal subgroup 16SrI-P) had been previously identified in several Po...

Many efforts have been made to develop a rapid and sensitive method for phytoplasma and virus detection. Taking our cue from previous works, different rapid sample preparation methods have been tested and applied to Candidatus Phytoplasma prunorum ('Ca. P. prunorum') detection by RT-qPCR. A duplex RT-qPCR has been optimized using the crude sap as a template to simultaneously amplify a fragment ...

Phytoplasmas associated with the plant diseases ash yellows (AshY, occurring in Fraxinus) and lilac witches'-broom (LWB, occurring in Syringa) represent a putative species-level taxon. Phytoplasmal DNA from 19 ash or lilac sources across the known geographic range of AshY (71-113 degrees W) was examined to determine if AshY and LWB phytoplasmas are a coherent group, if variability exists in bot...

Individual lines of Vitis vinifera Barbera and Chardonnay were obtained by in vitro culture of axillary buds collected from phytoplasma-affected mother plants. The molecular assays did not detect the “flavescence dorée” (FD) phytoplasma in the 66 lines tested after 6-9 months of culture, while the “bois noir”-associated phytoplasma was detected in 22 out of 50 lines. Despite the observed ineffi...