Two diseases of dimorphotheca caused by lettuce mosaic potyvirus and tomato spotted wilt tospovirus

In 1997, virus-like symptoms were observed in dimorphotheca plants (Dimorph otheca sinuata) at two different locations in Greece. In a greenhouse near Heraklion (Crete), plants showed chlorotic patches mainly in the older leav es, and a mild stunting; near Katerini (Macedonia), garden plants showed ch lorotic rings. Sap inoculation of healthy dimorphotheca plants with extract s from diseased plants from the two regions, reproduced each of the two dis eases. Examination by electron microscopy (EM) of samples from diseased pla nts from the first region revealed filamentous particles, whereas samples f rom the second region showed quasi-spherical particles. The filamentous par ticles were decorated in EM with antibodies specific to lettuce mosaic poty virus (LMV). Samples from the second location reacted with antibodies speci fic to tomato spotted wilt tospovirus (TSWV) in ELISA tests. It is conclude d that LMV and TSWV are the causal agents of the disease noticed in Herakli on and in Katerini, respectively.