Resistance to Tomato Yellow Mosaic Virus in Species of Lycopersicon . NICKOLAI M. PIVEN, Nucleo Experimental de Biotecnologia Agricola; Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A, Venezuela . RAFAELA C. de UZCATEGUI, Centro de Microbiologiay Biologia Celular, and DIOGENES INFANTEH., Nucleo Experimental de Biotecnologia Agricola, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A, Venezuela. Plant Dis. 79:590-594. Accepted for publication 14 December 1994. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0590.

Diseases caused by geminiviruses are widespread in the tropical subtropical tomato production areas. Tomato yellow mosaic geminivirus (ToYMV) is a member of the whitefly-transmitted subgroup (III), which is vectored by the whitefly Bemisia tahaci. Several accessions of Lycopersi-con chilense. I., hirsutunt, and L. peruvianum var. glandulosum were identified that exhibit tolerance or a high degree of resistance to a Venezuelan isolate of ToYMV in field and greenhouse studies using mechanical inoculation and viruliferous vectors. Polymerase chain reaction analysis showed that viral DNA is present in infected plants and absent in resistant ones. Mechanical and insect transmission gave different results in some species or cultivars, suggesting a distinct mechanism for resistance.

Keyword(s):