Occurrence of Fig badnavirus 1 in Fig trees from different countries and in symptomless seedlings

The consistent identification of Fig badnavirus 1 (FBaV-1) in the totality of samples from mosaic-affected fig trees from New Zealand (Minafra et al., 2012) and Italy (unpublished informa- tion), prompted the examination of additional samples from adult fig trees with mosaic symptoms from Italy (10), France (1), Greece (3), Albania (1), Spain (1), Portugal (1), England (1), Hungary (3), Montenegro (1), Lebanon (19), Syria (11), Tunisia (15), Algeria (2), Turkey (4), South Africa (1), Mexico (1), Cuba (1), and Aus- tralia (1). Additional samples from Italy consisting of volunteer symptomless seedlings (20) and symptomless potted plants de- rived from explants of mosaic-affected trees subjected to heat therapy (4), brought to over 100 the total number of sources ana- lyzed. Total RNA was silica-extracted from cortical scrapings and subjected to RT-PCR using the primers P1s: 5'-GCT GAT CAC AAG AGG CAT GA-3' and P1as: 5'-TCC TTG TTT CCA CGT TCC TT-3' designed on the sequence deposited in GenBank un- der the accession No. JF411989. A product with the expected size (214 bp) was amplified from all samples, regardless of the geo- graphical origin (18 countries) and the type of source (adult trees, seedlings, heat-treated plants). These results confirm what appears to be an amazing and unique association of FBaV-1 with Ficus car- ica. The extent of the association is such (100%) and involves trees from such a wide range of geographical origins, that makes it plausible, as in the case of other pararetroviruses (Staginnus and Richert-Pöggeler, 2006), the suggestion that FBaV-1 may be inte- grated in the fig genome; a likelihood further supported by the virus presence in volunteer fig seedlings.