Molecular Characterization of Divergent Isolates of Grapevine Red Blotch Virus from Blanc du Soleil, an Interspecific Hybrid White Grapevine Cultivar

Abstract

During routine virus screening, grapevine red blotch virus (GRBV; genus Grablovirus, family Geminiviridae) was detected in several samples of a recently released interspecific hybrid wine grapevine cultivar, Blanc du Soleil (BdS, US PP 34,483 P2, 2022). Molecular characterization of the BdS GRBV isolates revealed the presence of distinct complete genomes in nine isolates, with atypical lengths of 3,181 to 3,183 nucleotides (nt) relative to the expected 3,205 to 3,208 nt reported for GRBV isolates characterized to date globally. The difference in length was mainly due to deletions in the long intergenic region of the BdS GRBV isolates. In a phylogenetic reconstruction, the BdS GRBV isolates formed a monophyletic subclade basal to the clade II isolates to which they were more phylogenetically related than the clade I isolates. On average, complete genomes of these new isolates are 98.75% identical to each other, 96.66% identical to clade II isolates, and 92.02% identical to clade I isolates. Evolutionary analysis also revealed the occurrence of recombination in the history of these new isolates. [Figure: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Keywords

• Geminiviridae
• genetic diversity
• Grablovirus
• grapevine red blotch virus
• Vitis spp.
• wine grape