CORESTA Meeting, Agronomy/Phytopathology, Montreux,1997, AP10
Occurrence of eggplant mottled dwarf nucleorhabdovirus in tobacco crops in Greece
Aristotle University of Thessaloniki, Greece
In August 1993, unusual virus-like symptoms were observed in tobacco plants ( Nicotiana tabacum L.) of the cvs Myrodata Agriniou in the area of Agrinio (Central Greece). In 1994 and 1995 similar symptoms were noticed in the cv. Virginia in the area of Kilkis (Macedonia). Severe stunting, leaf curling and crinkling, chlorotic to yellow mottling of the leaves were the main symptomatology, occasionally accompanied by deep green vein banding or necrotic streaks along the veins. The diseased plants were mainly in the field margins and the disease incidence was very low (usually between 1-1.5%). Virus identification was based on mechanical inoculation of a number of indicator plants, serology, electron microscopy (decoration against EMDV, cytopathology) and western blot analysis. The virus was transmitted mechanically from field tobacco to a number of test plants: N. tabacum L. cv Samsun, Nicotiana rustica L., N. glutinosa L., N. clevelandii Gray, Petunia hybrida Vilm., Capsicum annuum L. cv Florinis and Lycopersicon esculentum Mill cv Dombo reacted with chlorotic local lessions followed by systemic vein clearing and leaf crinkling. Gomphrena globosa reacted only with reddish local lesions. Electron microscope decoration tests (of field samples) using EMDV antiserum revealed decorated bacilliform particles. In thin sections of leaf, numerous bacilliform and bullet-shaped particles were seen accumulating in perinuclear spaces and also in cytoplasmic vesicles. Serological (gel diffusion) tests confirmed identification of our isolate as EMDV, and its host range was similar to that reported for EMDV. Western blot analysis revealed that our isolate of EMDV, has a pattern similar to that of two German isolates from eggplant and tomato, respectively. Field symptoms were reproduced in tobacco plants (cvs. Myrodata Agriniou and Virginia) after mechanical inoculation.