Phytoplasma biodiversity in grapevines and leafhoppers sampled in vineyards of Quebec

Grapevine Yellows, caused by phytoplasmas, are economically important diseases that have been detected in most grape-growing regions of the world. Phytoplasma are mainly transmitted by leafhoppers that are phloem feeders. In order to better understand the epidemiology of phytoplasma diseases in grapevines grown in Quebec (QC), it is important to know phytoplasma strains occurring in leafhoppers and in grapevines. Leafhoppers and grapevines were sampled from 2009 to 2012 in QC vineyards. PCR tests were used to identify phytoplasma strains in grapevines and leafhopper species. In grapevines, strains of Aster Yellow phytoplasmas belonging to the subgroups 16SrI-A, -B, and -C were detected. In leafhoppers, phytoplasmas belonging to subgroups 16SrI-A, -B, -C, -S, -W, 16SrVII-A and 16SrIII were detected. Three new strains of phytoplasmas were found in grapevines and in insects. Phylogeny and biodiversity of phytoplasmas in QC vineyards are discussed.