Global phylogenic analysis of soybean dwarf virus isolates and their associations with aphid vectors and severe disease in soybeans

Authors: Stone, Andrew; DAMSTEEGT, VERNON - Retired ARS Employee; SMITH, ONEY - Hood College; Stewart, Lucy

Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2024
Publication Date: 1/6/2024
Citation: Stone, A.L., Damsteegt, V.L., Smith, O.P., Stewart, L.R. 2024. Global phylogenic analysis of soybean dwarf virus isolates and their associations with aphid vectors and severe disease in soybeans. Virology. 591:109984. https://doi.org/10.1016/j.virol.2024.109984.
DOI: https://doi.org/10.1016/j.virol.2024.109984

Interpretive Summary: Soybean dwarf virus (SbDV) was assessed for risk to U.S. soybean production for three decades at the Foreign Disease-Weed Science Research Unit. We report 22 new full-length SbDV genome sequences, including originally described Japanese yellowing and dwarfing strains, isolates from Syria and New Zealand associated with severe disease, and 18 isolates from U.S. field collections. We constructed a global phylogeny and revisited risk assessment based on sequences and biological data including crop disease severity and aphid vector. We conclude that U.S. SbDV isolates are still not a major threat to U.S. soybean production without major shifts in both aphid and virus populations, but posit that endemic isolates do have potential to impact other leguminous crops such as clover, peas and lentils. These findings provide sequence-based indicators of biology and associated agricultural risk of global SbDV isolates.

Technical Abstract: Soybean dwarf virus (SbDV) was first described in Japan as an agent of severe soybean disease transmitted by the foxglove aphid, Aulacorthum solani (S), with separable yellowing (Y) and dwarfing (D) strains. SbDV of both Y and D genotypes were later documented in other countries. For three decades, SbDV isolates were assessed to evaluate risk to U.S. soybean production. U.S. SbDV isolates were transmitted by the pea aphid Acyrthosiphum pisum (P) and showed limited disease in soybeans, suggesting it was not a major threat to U.S. soybean production. Here we report 22 new full-length SbDV genome sequences including those of the originally described Japanese Y and D isolates, isolates from Syria and New Zealand associated with severe disease, and 18 isolates from U.S. field collections. Using these new full-length genomes, a global phylogeny was assembled and used to revisit risk assessment based on sequence similarities, isolate pathogenicity, and vector specificity.