Ricardo J G Pimenta, Kyle Macleod, Robyn Babb, Kaitlyn Coleman, Joni MacDonald, Elvis Asare-Bediako, Max J Newbert, Carol E Jenner, John A Walsh

Turnip yellows virus (TuYV; Polerovirus, Solemoviridae) infects and causes yield losses in a range of economically important crop species, particularly the Brassicaceae. Although the incidence and genetic diversity of TuYV has been extensively investigated in recent years, little is known about how the diversity within host plants relates to that in its vectors. Arable oilseed rape (Brassica napus) and vegetable brassica plants (Brassica oleracea), wild cabbage (B. oleracea), and aphids present on these plants were sampled in the field in three regions of the United Kingdom. High levels of TuYV (82 to 97%) were detected in plants in all three regions following enzyme-linked immunosorbent assaysComparative analyses between TuYV sequences from host plants and B. brassicae collected from respective plants revealed differences between some ORF0 sequences, which possibly indicated that at least two of the aphids might not have been carrying the same TuYV isolates as those present in their host plants. Maximum likelihood phylogenetic analyses revealed three distinct major clades for ORF0 and one for ORF3, with some distinct subclades. Some clustering was related to geographic origin. Explanations for TuYV sequence differences between plants and the aphids present on respective plants and implications for the epidemiology and control of TuYV are discussed.

Plant Disease. March 2024