Characterisation of turnip mosaic virus isolates reveals high genetic variability and occurrence of pathotype 1 in Brazil

Turnip mosaic virus (TuMV) infects many plant species, being the only potyvirus able to infect brassicas. TuMV isolates have been classified into 12 pathotypes according symptoms induced in lines of Brassica napus, and molecularly clustered six lineages (basal-B, basal-BR, Asian-BR, world-B, Iranian OMs). Despite considered one most important viruses infecting brassicas worldwide, there is little information on this Neotropical region. Aiming fill gap advance knowledge occurrence, genetic variability, biological aspects Brazil, 40 were identified characterised. Five these selected determine their host range, sequence genomes, for phylogenetic, recombination diversity analyses. Mechanical inoculations performed species from 10 families showed differences symptom expression among isolates. Inoculations 13 B. napus revealed occurrence pathotype 1. According phylogenetic analyses coat protein, Brazilian groups: world-B (subgroups world-B2 world-B3) basal-BR. In latter, was a formation subclade named subgroup composed by 31 Intralineage interlineage events basal-B basal-BR suggest that had European origin. Our analysis strong negative selection acting polyprotein coding We confirmed high which together with ability wild circumvent resistance genes highlight epidemiological potential causing damages cultivated other crops Brazil.