Coniella vitis sp. nov. Is the Common Pathogen of White Rot in Chinese Vineyards

Abstract

Grape white rot is a common disease and causes considerable yield losses in many grape-growing regions when environmental conditions are favorable. We surveyed grape white rot in five provinces in China and collected 27 isolates from diseased grape tissues. Multigene phylogenetic analyses of the internal transcribed spacer region (ITS1-5.8S-ITS2), the 28S large subunit of nuclear ribosomal RNA (LSU), partial translation elongation factor 1-alpha gene (TEF 1-α), and partial histone 3 gene (HIS), coupled with genealogical concordance phylogenetic species recognition and morphological observations, revealed that Coniella vitis sp. nov. and C. diplodiella are the causal agents of grape white rot in China. Koch's postulates were performed on Vitis vinifera cv. Summer Black in a greenhouse. These results confirmed the pathogenicity on grapes, as symptoms were reproduced, and also indicated significant variations in the virulence among C. vitis isolates. This work provides evidence that C. vitis is the main pathogen of grape white rot in China and also provides an optimized multigene backbone for resolving Coniella species.