[Structurally dependent effects of substituted thioureas on the concentration of potato virus X in Nicotiana tabacum L. "Samsun" (author's transl)].

A study has been made to investigate the effects of N-alkyl- and aryl-substituted thioureas as well as N,N'-alkyl-alkyl-, alkyl-aryl-, and aryl-aryl-substituted thioureas on the multiplication of PVX in Nicotiana tabacum L. "Samsun". The virus concentrations of the treated plants were serologically determined and compared with these of untreated controls. The weak antiphytoviral effect of nonsubstituted thiourea remained virtually unchanged in N,N'-dimethyl thiourea, and in N,N,N'-trimethyl thiourea. A stronger antiphytoviral effect was observed for N-phenyl, N',N'-pentamethylene thiourea, as well as N-methyl thiourea. All other substitutions, especially those by longer-chain substituents or by a larger number of substituents, were not found to have an influence on viral multiplication.