Differential distribution and titre of selected grapevine leafroll-associated virus 3 genetic variants within grapevine rootstocks.

In this study of three grapevine leafroll-associated virus 3 (GLRaV-3) genetic variants in two grapevine rootstock hosts, GLRaV-3 detection was shown to be affected by the virus distribution, titre, and the genetic variant. Group VI and NZ2 GLRaV-3 variants had reduced detectability compared with the group I variant. Differences in the genomic and subgenomic RNA (sgRNA) expression levels, and differences in the level of expression between the genetic variants were also observed. The observed differences in virus titre and sgRNA expression levels suggest differences in plant-virus interactions by the various GLRaV-3 genetic variants.