Some hosts and properties of dahlia mosaic virus

Abstract

S U M M A R YDahlia mosaic virus (DMV) infected twenty-five of the eighty-five plant species from four of eighteen families inoculated, but only dahlias were found naturally infected. DMV infected fourteen members of the Solanaceae, Amaranthaceae and Chenopodiaceae, and eleven of twenty-nine Compositae. Verbesina encelioides was the best plant for diagnosis, assay and source of virus. Systemically infected hosts contained ovoid intracellular inclusions 2.5-10 pm in diameter which were shown by electron microscopy to consist of a finely granular, vacuolated matrix containing numerous virus particles. V. encelioides sap was sometimes infective after dilution to 1/2000 but not 1/3000, after heating for 10 min to 75 "C but not 80 "C, and after 4 days at 18 "C or 32 days at 2 "C. Sap from infected dahlia, Zinnia elegans or Ageratum houstonianum rapidly became non-infective, but extracts made with 0.05 M sodium thioglycollate or 0.03 M sodium diethyldithiocarbamate remained infective for R E S U L T S Detection, field occurrence and identity of the virus Detection.Dahlia leaves contain much phenolic material; this, and the activity of dahlia leaf phenoloxidase, are both increased by virus infection (Martin, 1954;Lawson & Taconis, 1965). Early failures to transmit DMV from infected to healthy dahlias by mechanical inoculation of sap (Brierley, 1933), and transmission rates of 10% or less obtained later (Brierley & Smith, 1950), probably resulted from the rapid inactivation of virus by o-quinones or other complex phenolic materials. Inactivation can be de-

Dahlia Mosaic Virus: Molecular Detection and Distribution in Dahlia in the United States

“…DMV is an important viral pathogen of dahlias in the U.S. and several parts of the world (Brunt, 1971). It was fi rst reported in Dahlia pinnata from Germany in 1928.…”

“…The host range and some properties of DMV were described by Brunt (1971). A member of the genus Caulimovirus of family Caulimoviridae, the genome of DMV consists of a circular double stranded-DNA, about 7 kb in size (Richins and Shepherd, 1983).…”

Plant pararetroviral sequences in wild Dahlia species in their natural habitats in Mexican mountain ranges

“…All but one are RNA viruses. Dahlia mosaic virus (DMV), a DNA virus, is widely prevalent in cultivated dahlias and causes an economically important disease referred to as dahlia mosaic (Brunt, 1971; Albouy, 1995). Based on molecular characterization, DMV is considered a distinct species in the genus Caulimovirus (Richins & Shepherd, 1983).…”

Untangling the taxonomy of dahlia mosaic virus

“…Dahlia mosaic is one of the most prevalent and damaging viral diseases of dahlia ( Dahlia variabilis ) in Europe and the USA [ 4 , 19 ]. Dahlia mosaic virus (DMV), the putative causative agent of the disease, was one of the first officially recognized members of the genus Caulimovirus (initially called the ‘cauliflower mosaic virus group’), appearing in the first report of the International Committee on Nomenclature of Viruses, published in 1971 [ 23 ].…”

“…Nevertheless, there was strong evidence at the time to support the classification of DMV and cauliflower mosaic virus (CaMV) as closely related but distinct members of this virus genus. The characters that were used for classification included the size and shape of the virion, the presence of electron-dense inclusion bodies in the cytoplasm of infected cells, the mode of transmission, differences in host range, and weak serological relatedness of the viruses in gel diffusion tests [ 3 , 4 ].…”