VIEW ARTICLE

Disease Detection and Losses

Detection and Distribution of Geminiviruses in Mexico and the Southern United States. Irineo Torres- Pacheco, Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato, Apartado Postal 629, Irapuato, Gto. México; J. Antonio Garzón-Tiznado(2), Judith K. Brown(3), Alicia Becerra-Flora(4), and Rafael F. Rivera-Bustamante(5). (2)(4)(5) Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato, Apartado Postal 629, Irapuato, Gto. México; (3)Department of Plant Sciences, University of Arizona, Tucson. Phytopathology 86:1186-1192. Accepted for publication 5 August 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/Phyto-86-1186.

Plant samples from important horticultural areas in Mexico and the southern United States were collected during several seasons and analyzed for the presence of geminiviruses by a combination of agarose gel electrophoresis, molecular hybridization, and polymerase chain reaction amplification techniques. A general detection strategy confirmed the presence of geminiviruses in all horticultural areas of Mexico in pepper, tomato, tomatillo (Physalis ixocarpa), cucurbits, and tobacco. Specific detection procedures showed that pepper huasteco virus is widely distributed in Mexico; it was found in pepper and tomato samples in both coastal areas, as well as in central Mexico. It was also found in pepper samples from the Rio Grande Valley in southern Texas. Pepper jalapeño virus (PJV) and chino del tomate virus (CdTV) showed a more restricted distribution, although, in all cases, the viruses appeared to become more widely distributed over time. Partial DNA sequences of PJV and CdTV were also obtained. Comparative sequence analysis showed that PJV and the previously described Texas pepper geminivirus are probably strains of the same virus. The name pepper jalapeño virus is, thus, withdrawn to avoid further confusion. Similarly, CdTV showed a very high level of sequence identity with the recently described tomato leaf crumple virus (TLCrV), also suggesting that they both are strains of the same virus.