DisplayTitle

Identification, Characterization, and Relatedness of Luteovirus Isolates from Forage Legumes

First, second, and fourth authors: USDA-ARS, NAA, Foreign Disease-Weed Science Research Unit, Fort Detrick, MD 21702; third author: Mount St. Mary's College, Emmitsburg, MD 21727; fifth author: Department of Plant Pathology, Pennsylvania State University, University Park 16801; and sixth author: Department of Biology, Hood College, Frederick, MD 21701

Virus isolates from forage legumes collected from eight different states were identified as luteoviruses closely related to soybean dwarf luteovirus dwarfing (SbDV-D) and yellowing (SbDV-Y) described in Japan. All isolates produced reddened leaf margins in subterranean clover and were transmitted in a persistent manner by Acrythosiphon pisum, but not by Aulacorthum solani. Specific monoclonal antibodies raised against SbDV-Y were differentially reactive with endemic isolates. Immunoblots probed with a SbDV-D polyclonal antiserum showed single 26-kDa coat protein bands, confirming close serological relatedness to SbDV. Analyses of genomic and subgenomic double-stranded RNAs and northern blot analyses confirmed genomic relatedness to SbDV. Based on our results, we conclude that the U.S. luteovirus isolates studied comprise a strain or strains of the soybean dwarf virus that have clovers as common hosts and the pea aphid as a common vector.

Additional keywords: vector-specific strains.