High Genetic Diversity and Species Complexity of Associated With Grapevine Dieback in China.

Grapevine trunk diseases have become one of the main threats to grape production worldwide, with species as an emerging group of pathogens in China. At present, relatively little is known about the taxonomy and genetic diversity of Chinese populations, including their relationships to other populations worldwide. Here, we conducted an extensive field survey in six provinces in China to identify and characterize species in grape vineyards. Ninety-four isolates were identified and analyzed using multi-locus phylogeny. The isolates belonged to eight species, including three novel taxa, , and three new host records, , and . The most commonly isolated species was . In addition, high genetic diversity was observed for in Chinese vineyards. Haplotype network analysis of isolates from China and Europe showed a close relationship between samples from the two geographical locations and evidence for recombination. In comparative pathogenicity testing, was the most aggressive taxon, whereas was the least aggressive. This study provides new insights into the species associated with grapevines in China, and our results can be used to develop effective disease management strategies.