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A new virus was isolated from tomato plants from the Murcia region in Spain which showed symptoms of ‘torrado disease’; very distinct necrotic, almost burn-like symptoms on leaves of infected plants. The virus particles are isometric with a diameter of approximately 28 nm. The viral genome consists of two (+)ssRNA molecules of 7793 (RNA1) and 5389 nts (RNA2). RNA1 contains one open reading frame (ORF) encoding a predicted polyprotein of 241 kDa that shows conserved regions with motifs typical for a protease-cofactor, a helicase, a protease and an RNA-dependent RNA polymerase. RNA2 contains two, partially overlapping ORFs potentially encoding proteins of 20 and 134 kDa. These viral RNAs are encapsidated by three proteins with estimated sizes of 35, 26 and 23 kDa. Direct protein sequencing mapped these coat proteins to ORF2 on RNA2. Phylogenetic analyses of nucleotide and derived amino acid sequences showed that the virus is related to but distinct from viruses belonging to the genera Sequivirus, Sadwavirus and Cheravirus. This new virus, for which the name tomato torrado virus is proposed, most likely represents a member of a new plant virus genus. [ABSTRACT FROM AUTHOR]

In October 2006, tomato plants with torrado disease were sampled in Spain. In a sample of cv. Mariana, originating from Gran Canaria, Tomato torrado virus (ToTV, genus Torradovirus) was detected (isolate GCN06; Alfaro-Fernández et al., 2010). In 2013, the sample was further analysed using next-generation sequencing (NGS). Total RNA, extracted from ca. 150 mg of leaf tissues, was used for an RNA library suitable for Illumina HiSeq paired end sequencing. A de novo assembly (using CLC Genomic Workbench v.6.5) resulted in 1380 sequence contigs. BLAST searches revealed the presence of ToTV and Tomato chlorosis virus (ToCV, genus Crinivirus). One contig (3427 nts, 8901 reads), showed 99.85% identity with Southern tomato virus (STV, genus Amalgavirus), isolate Mexico-1 (GenBank accession No. EF442780), a dsRNA seed-transmitted virus (Sabanadzovic et al., 2009). Reference assembly with the Mexico-1 sequence resulted in a partial sequence of 3420 nts (GenBank KJ174690). The presence of STV in sample GCN06 was verified in RT-PCR using the specific primers STV-fw and STV-rev (Candresse et al., 2013) and sequencing of the obtained amplicon. A new sampling in May 2014 in Gran Canaria revealed the presence of STV in six out of seven tomato samples of cv Mariana. All these samples were co-infected with Pepino mosaic virus (PepMV, genus Potexvirus), Tomato spotted wilt virus (TSWV, genus Tospovirus), and Tomato yellow leaf curl virus (TYLCV, genus Begomovirus). Because STV was generally found in samples co-infected with other viruses, its symptomatology in tomato remains unclear. To our knowledge, this is the first report of STV in the Canary Islands and Spain. [ABSTRACT FROM AUTHOR]