First report of Solanum sisymbriifolium and S. americanum as natural weed hosts of Tomato chlorosis virus (genus Crinivirus) in South America.
Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus are emergent Crinivirus species of tomatoes (Solanum lycopersicum). So far, only ToCV has been detected on tomato crops in South America. Sticky nightshade (S. sisymbriifolium) and American nightshade (S. americanum) plants showing severe foliar interveinal yellowing similar to crinivirus-induced symptoms were found during surveys carried out from 2012 to 2014 in Salto, Uruguay. These weeds were heavily colonized by Trialeurodes vaporariorum and Bemisia tabaci biotype Q. Leaf samples were collected and total RNA was extracted to verify if these weeds function as reservoirs of tomato criniviruses. Based on the results of PCR assays, dot blot hybridization test and nucleotide sequence analysis, the presence of ToCV in S. sisymbriifolium and S. americanum was confirmed. This is thought to be the first report of these solanaceous weeds as natural ToCV hosts in South America and the first worldwide report of S. sisymbriifolium as a crinivirus host.