In the spring and summer of 1997, nearly 90% of dill plants (Anethum graveolens L.) cultivated in a crop of Emilia-Romagna region (northern Italy), exhibited viruslike symptoms. Approximately 30% of the plants showed narrowing of the leaf lamina and stunting that evolved to yellow or bronze color. The plants appeared bushy and had low seed production. Electron microscopy of leaf-dip preparations revealed the association of flexuous, potyvirus-like particles of 750 nm in length with diseased dill plants. The identity of this virus was established by differential host reactions and serological assays. It was mechanically transmitted only to Chenopodium amaranticolor Coste et Reyn. and C. quinoa Willd. plants (which showed local chloro-necrotic lesions after about a week), and Petunia × hybrida Hort. Vilm.-Andr. plants (latently infected). No infections were obtained in several inoculated Umbelliferae plants, including dill and celery (Apium graveolens L.). Therefore, our isolate is similar to that described by others (1,2) and unlike the type strain that infects only members of the Umbelliferae. Virus particles reacted in protein A sandwich-enzyme-linked immunosorbent assay with antiserum to celery mosaic potyvirus (CeMV) (supplied from the Istituto di Fitovirologia Applicata, CNR, Turin, Italy). This result was further confirmed by immunosorbent electron microscopy decoration tests. CeMV in the field was likely transmitted to dill by abundant aphid populations from weeds and/or other Umbelliferae species cultivated in the same location. In particular, the weed host Daucus carota L. and the cultivated Petroselinum sativum Hoffm. plants both exhibited bronze foliage and stunting, and were found to be infected by CeMV. This note represents the first report of CeMV in A. graveolens.
References: (1) E. Luisoni et al. Ann. Phytopathol. 1:375, 1969. (2) C. Rubies-Autonell et al. Phytopathol Mediterr. 35:58, 1996.