L. Tomassoli*, A. Zaccaria and M. Barba

Istituto Sperimentale per la Patologia Vegetale, Rome, Italy

*l.tomassoli@ispave.it

Accepted for publication: 20/08/04

In spring 2004, a survey was conducted to investigate the phytosanitary status of caper (Capparis spinosa L.) crops in Sicily, the Eolie Islands (Salina and Lipari) and Pantelleria. Two viruses have previously been isolated from caper in Salina (Campo et al., 2000): Caper latent virus (CapLV, genus Carlaviruses, family Flexiviridae) (Gallitelli & Di Franco, 1987) and Pittosporum vein yellowing virus (PVYV, genus Nucleorhabdovirus, family Rhabdoviridae) (Nuzzaci et al., 1993).

Figure 1: Symptoms of reddish mottle on caper plants infected by CMV from Lipari island

Crude sap taken from collected leaf samples was used to mechanically inoculate the experimental host species Chenopodium quinoa, C. amaranticolor, Nicotiana benthamiana and N. glutinosa. Some samples from the Eolie crops produced chlorotic local lesions on Chenopodium spp., a few days post inoculation and severe systemic mosaic, leaf malformations and shoestringing on Nicotiana spp., resembling symptoms caused by Cucumber mosaic virus (CMV, genus Cucumovirus, family Bromoviridae). ELISA, using a CMV-specific rabbit polyclonal antiserum (ISPaVe-CMV22) detected the presence of the virus in samples from Salina and Lipari. To characterise the virus isolates, total RNA was extracted from caper leaves (Qiagen, RNeasy Plant Mini Kit) and was analyzed in a one-step RT-PCR using primer sets CMV-CPI or CMV-CPII (Lumia et al., 2001), specific to I and II subgroups of CMV respectively. An amplified product of the expected size was mostly commonly obtained when CMV-CPI primers were used (672bp), less frequently with CMV-CPII primers (674bp). In a few samples both subgroups were detected.

Figure 2: Symptoms of vein yellowing (left) and yellow ringspot (right) on caper plants from Salina island infected by CMV and PVYV.

During the spring, CMV was detected in plants showing reddish mottle (Fig. 1), vein yellowing and yellow rings or spots (Fig. 2), and in caper plants without symptoms, that showed interveinal leaf chlorosis on a few basal shoots later in summer (Fig. 3). Plants with yellowing disorder were found to be infected with both CMV and PVYV. No CMV infected plants were detected in Pantelleria. This is the first report of Capparis spinosa L. as a natural host of CMV and adds a new plant family, Capparaceae, to the already wide virus host range.

Figure 3: Interveinal leaf chlorosis of basal shoot on plants infected by CMV from Salina.

This work was supported by the Regione Sicilia – Italy

Campo G, Di Natale A, Tomassoli L, Barba M, 2000. Deperimento di capperi nell’isola di Salina. L’Informatore Agrario 56 (36), 67-69.

Gallitelli D, Di Franco A, 1987. Characterization of Caper Latent virus. Journal of Phytopathology 119, 97-115.

Nuzzaci M, De Stradis A, Rana GL, Camele I, 1993. Identità sierologica tra i virus dell’ingiallimento nervale del cappero e del pittosporo. Petria 3, 99-107.

Lumia V, Ilardi V, Tomassoli L, Barba M, 2001. Trangenes detection in industrially processed genetically modified tomato. Petria 11, 159-165.

The British Society for Plant Pathology