Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 11, 2002
Publication Date: December 1, 2002
Interpretive Summary: Many non-crop species in the genus Solanum have previously been shown to host viruses naturally and/or experimentally but to the best of our knowledge, this is the first report of Key West nightshade being a host for any plant virus. This report demonstrates that Key West nightshade meets our needs as a long-lived TSWV host. We work with many isolates of TSWV in a single experiment and Key West nightshade provides a means of keeping fresh, infected tissue for multiple isolates available simultaneously for months on end. This report also suggests that Key West nightshade may find more general application as a perennial host for viruses of herbaceous plants, making another experimental tool available to plant virologists
Technical Abstract: Key West nightshade (Solanum bahamense L.) is a perennial solanaceous weed found in the extreme southern portion of Florida. It can be propagated by seed and cuttings and is absent from the noxious weed lists of all US states. Its susceptibility to five viruses common to Florida was evaluated by mechanical inoculation of leaves with Tomato spotted wilt virus (TSWV), Tobacco mosaic virus (TMV), Pepper mild mottle virus (PMMoV), Cucumber mosaic virus (CMV) and a putative tobamovirus recently isolated from hibiscus in Florida (HV). TSWV induced chlorotic rings on inoculated leaves and mosaic and malformation of uninoculated leaves. CMV induced necrotic local lesions on inoculated leaves. No symptoms were observed following inoculation with TMV, PMMoV or HV. TSWV, TMV and PMMoV systemically infected S. bahamense as determined by the use of enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, viral-associated double-stranded RNA analysis and/or indicator hosts. Active growth of infected plants continued for seven months following inoculation making S. bahamense suitable for long-term maintenance of viruses in planta. We suggest that S. bahamense may be a useful host for virus culture collections and for studies involving large numbers of virus isolates where fresh, infected tissue is continuously required.