Disease Note.

First Report of Viruses in Asparagus Plantings in Mexico. M. Rafael, Centro de Investigaci6n y de Estudios Avanzados del IPN, Unidad Irapuato, Apdo, Postal 629, Irapuato, Gto. Mexico. A. Becerra, and R. Rivera-Bustamante, Centro de Investigaci6n y de Estudios Avanzados del IPN, Unidad Irapuato, Apdo, Postal 629, Irapuato, Gto. Mexico. Plant Dis. 78:1123. Accepted for publication 19 July 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1123D.

Asparagus (Asparagus officinalis L.) plantings in the state of Guanajuato, Mexico, have shown a severe decline in yield during the last 10 yr. Since loss of productivity and vigor was correlated in several countries to the presence of viruses (1,2), a survey was done to detect viruses in asparagus in Guanajuato. Virus indicator plants such as Chenopodium quinoa Willd., C. amaranticolor Coste & Reyn., Vigna unguiculata (L.) Walp. cv. California Blackeye, Nicotiana tabacum L. cv. Xanthi and Xanthi nc, and N. benthamiana Domin. were mechanically inoculated with the tissue of young asparagus spears from (he field, ground in buffer (0.01 M potassium phosphate buffer, pH 7.0, 1% PVP, 0.02 M ?-mercap-toethanol). Inoculated plants were maintained under greenhouse conditions, and viruslike symptoms were observed 10-15 days after inoculation. The symptoms observed in each host were characteristic for viruses previously reported in asparagus (I). Symptomatic plants (indicator hosts) and field asparagus were assayed by ELISA and confirmed in a number of cases by immuno dot blot, Western blot, and dsRNA analysis. Two ilarviruses (asparagus virus 2 [AV2] and tobacco streak virus [TSV)) and a potyvirus, most likely asparagus virus 1 (AVI) were detected. The viruses were widely distributed in the state and, in most cases, were present in mixed infections. Cucumber mosaic virus, tobacco mosaic virus, cauliflower mosaic virus, watermelon virus 1, watermelon virus 2, and strawberry latent ringspot virus were not detected by ELISA. To our knowledge, this is the first report of asparagus viruses (AVI and AV2) as well as TSV in Mexico.