Recombination profiles between Tomato yellow leaf curl virus and Tomato yellow leaf curl Sardinia virus in laboratory and field conditions: evolutionary and taxonomic implications
Tomato yellow leaf curl Sardinia virus and Tomato yellow leaf curl virus have co-existed in Italian tomato crops since 2002 and have reached equilibrium, with plants hosting molecules of both species plus their recombinants being the most frequent case. Recombination events are studied in field samples, as well as in experimental co-infections, when recombinants were detected as early as 45 days following inoculation. In both conditions, recombination breakpoints were essentially absent in regions corresponding to ORFs V2, CP and C4, whereas density was highest in the 3′-terminal portion of ORF C3, next to the region where the two transcription units co-terminate. The vast majority of brea…
The complete nucleotide sequence of an isolate of Tomato yellow leaf curl Sardinia virus found in Sicily
Partial sequences of Tomato yellow leaf curl Sardinia virus (TYLCSV) derived from tomato samples collected in Sicily in 1999, 2002 and 2004 indicated the presence of a TYLCSV different from the one previously described as the Sic strain. Here, we report a complete DNA sequence that is classified as belonging to the TYLCSV type strain (Sar strain), confirming the co-existence in Sicily of virus populations of both strains. Moreover, comparisons between this new sequence and those of the two recombinants recently described in Sicily revealed unequivocally (99% identity) that their TYLCSV-derived portion originated from the Sar strain. © 2010 Springer-Verlag.