Fst values and Ks*, Z* and Snn tests between pairs o CTV populations for the p20 gene.

*Geographical regions: Argentina, California (USA), New Zealand, Pakistan, Spain, and Italy. Italy has been subdivided between the Sicily island and Apulia (peninsular Italy). The Italian sequences are: 110 from Sicily (108 determined in this work and two from GenBank), six from Apulia (Southeastern of Italian peninsula) and one from Calabria (Southwestern of Italian peninsula).†N = number of CTV isolates.‡Fst provides an estimate of the extent of gene flow between populations. A value of zero corresponds to genetically undifferentiate populations, whereas a value of one indicates genetically isolated populations.§No significant genetic differentiation (P>0.05) evaluated with the Ks*, Z* and Snn tests.