First report of eggplant Mottled Dwarf Virus in China rose in southern Spain

Eggplant mottled dwarf virus (EMDV) is a member of the genus Nucleorhabdovirus in the family Rhabdoviridae (order Mononegavirales) (Tordo et al., 2005). The EMDV genome is composed of a linear, single stranded and negative-sense molecule of RNA, contained in enveloped bacilliform particles of 220-232 × 66-72 nm (Martelli et al., 2011). The virus is transmitted in nature by the leafhoppers Anacerato-gallia laevis, A. ribauti and Agallia vorobjevi (Della Giustina et al., 2000; Babaie & Izadpanah, 2003), but the mode of transmission is still unclear. Natural host range of EMDV comprises crops (eggplant, tomato, potato, pepper, tobacco), ornamentals (pittosporum, China rose, honeysuckle, pelargonium), and wild plant species (caper, Solanum nigrum and S. sodomaeum) (Roggero et al., 1995; Martelli et al., 2011). The prevalence of infections is generally very low (1-5%), with some exceptions recorded in Algeria and Jordan where moderate infections of about 20% have been reported on eggplant (Martelli & Hamadi, 1986; Al-Musa & Lockhart, 1990). More recently, EMDV was demonstrated to be the causal agent of vein yellowing disease in China rose (Hibiscus rosa-sinensis L.) plants growing in southern Italy and in imported plantlets (De Stradis et al., 2008). Vein yellowing symptoms similar to those observed in Italy were noticed for the last few years in China rose plants growing in public gardens in southern Spain (Fig. 1). During summer 2011, three locations from Málaga province (Rincón de la Victoria, Torre del Mar and Caleta de Vélez) and one from Granada province (La Herradura), were surveyed to study the prevalence, distribution and association of EMDV infections with vein yellowing disease in H. rosa-sinensis by serological and molecular methods.