First Report of Rhabdoviruslike Particles in Croton (Codiaeum variegatum). M. G. Bellardi, Istituto di Patologia Vegetale, UniversitÓ degli Studi, Bologna, Italy 40126. A. Bertaccini, A. Villani, and V. Vicchi. Istituto di Patologia Vegetale, UniversitÓ degli Studi, Bologna, Italy 40126, and Osservatorio Regionale per le Malattie delle Piante di Bologna, Italy 40100. Plant Dis. 75:862. Accepted for publication 12 February 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0862A.
Dwarf plants of croton (Codiaeum variegatum (L.) Blume 'Fred Sander') showing malformation and yellow or pink veins were observed in a greenhouse in the Emilia-Romagna region of northern Italy in spring 1990. Leaf-dip preparations stained with 2% potassium phosphotungstate, pH 7.0, revealed bullet-shaped virus like particles. Thinsection electron microscopy of symptomatic leaves disclosed a large number of bacilliform particles resembling known rhabdoviruses in parenchymatic cells. The particles, measuring 70-80 X 180-240 nm, accumulated in the extended cisternae of perinuclear space at the periphery of the nucleus. The individual virions found inside the cisternae were randomly oriented or in paracrystalline arrangement, side by side. The rhabdovirus was transmitted by mechanical inoculations to Nieotiana glutinosa L. and Chenopodium amarantieolor Coste & Reyn., which showed systemic veinclearing and leaf deformations. The leaf graft method was used to transmit the virus to healthy croton, which showed dwarfing, vein yellowing, and leaf malformation. To our knowledge, this is the first report of a rhabdovirus in C. variegatum.