Grapevine Pinot gris virus in Germany: From where did the virus come, and when?

Grapevine Pinot gris virus (GPGV) isolates were obtained from German vineyards to investigate their diversity. Phylogenetic and dating analyses of these and GPGV genes and genomes available in GenBank showed that the virus probably diverged from grapevine berry inner necrosis virus (GINV) in wild and cultivated Vitis species, notably Vitis coignetiae, growing in North-east Asia around 3500 years ago. GPGV probably infected the Eurasian grape (Vitis vinifera subsp. vinifera) when those cultivars were first taken to China during the Han Dynasty (226 BCE-220 CE). GPGV then spread to Europe around 1800 CE, probably via the dissemination of infected plants, and from there, eventually spread worldwide. German isolates were only found in all parts of the post-1800 CE phylogeny. The German isolates were genetically more diverse, for both MP and CP genes, than those of other European populations, suggesting that the initial stages of the GPGV invasion of Europe were in Germany, not Italy. We discuss the likely North-east Asian origin of both GPGV and GINV, and the possible coincidences of phylogenetic date estimates with changes to European and world viticulture practices.