Molecular characterization of turnip yellows virus isolates from canola in Serbia

Abstract

In November 2019, virus-like symptoms resembling those caused by turnip yellows virus (TuYV) were observed in many canola crops across Serbia. In order to identify their causal agent, a total of 206 samples were collected and analyzed for the presence of TuYV, cauliflower mosaic virus (CaMV) and turnip mosaic virus (TuMV), using commercial double-antibody sandwich (DAS)-ELISA kits. TuYV was detected serologically in 91.75% of tested samples collected at 24 locations in all of seven inspected districts. None of the samples tested positive for TuMV and CaMV. Further molecular characterization based on the partial P0 gene sequences of seven selected ELISA-positive samples showed that Serbian TuYV isolates collected in 2019 shared low nucleotide diversity, and that they were closely related to previously identified Serbian cabbage and mustard isolates of TuYV. Phylogenetic analysis showed that TuYV isolates from Serbia were clustered within the TuYV/BrYV group. Moreover, nucleotide and amino acid sequence comparison of all TuYV isolates originating from Serbia, supported with a phylogenetic tree, indicated the existence of two virus subpopulations in Serbia. Further research should focus on determining the variability of TuYV population in Serbia, based on a whole-genome analysis that will contribute to a better understanding of the epidemiology of this pathogen, aiming at developing and implementing appropriate control measures.