Etiology of yellow spot of potatoes, grown in the Central Platou of Mexico

• Published in: Revista mexicana de fitopatologia Vol. 10; no. 1
• Main Authors: Diaz Valasis, Margarita (Instituto Nacional de Investigaciones Forestales y Agropecuarias, Mexico, D.F. (Mexico), Apdo. Postal 10 56230 Chapingo, Mex.), Cadena Hinojosa, Mateo A. (Colegio de Postgraduados, Montecillo, Mex. (Mexico), Centro de Fitopatologia)
• Format: Journal Article
• Language: Spanish
• Published: 1992
• Subjects: ETIOLOGIE; FEUILLE; MEXICO (PROVINCE); SOLANUM TUBEROSUM; TACHE; VARIETE; VIRUS DES VEGETAUX
• ISSN: 0185-3309; 2007-8080

Yellow spots have been observed on the lower leaves of commercial varieties of potato around the "Nevado de Toluca" volcain in Mexico State. Disease incidence was low (1). None of the common potato viruses (PVX, PVS, PVY or PLRV) were detected through serology, electron microscope and indicator plants. Potato plants mechanically inoculated with sap from plants with yellow spots gave a positive reaction to alfalfa mosaic virus (AMV) by ELISA technique. Generalized yellow spots were observed on "Rojita" cultivar, at the Valley of Mexico, from which local lesions and systemic symptoms have been transferred to several tobacco species. Chenopodium quinoa. Ch. amaranticolor, Gomphrena globosa, and necrotic local lesions were produced in Phaseolus vulgaris "Pinto". When virus free plants of Rojita and Lopez were inoculated with sap from plants with generalized yellow spots, clear symptoms of yellow spots were developed and the percentage infection was 80 and 20 respectively. Seed-tuber transmission was recorded and symptoms in plants of Rojita and Lopez were very conspicuous. Manchas amarillas en el follaje inferior de variedades comerciales de papa se han observado en las faldas del Nevado de Toluca Mex. La incidencia de las manchas no pasa del 1. Ninguno de los virus comunes en papa (PVX, PVS, PVY o PLRV) se detecto en colectas de diferentes localidades de esta region, mediante serologia, microscopia electronica y plantas indicadoras. El virus del mosaico de la alfalfa se detecto por ELISA en plantas inoculadas mecanicamente con savia de plantas con sintomas de manchas amarillas. Manchas amarillas generalizadas se han observado en el cultivar Rojita en el Valle de Mexico y de las cuales se han obtenido lesiones locales y sintomas sistemicos en diferentes especies de tabaco, Chenopodium quinoa, Chenopodium amaranticolor y Gomphrena globosa; y lesiones locales necroticas en Phaseolus vulgaris "Pinto". Plantas de Rojita y Lopez, libres de virus e inoculadas con savia de plantas con sintomas de manchas amarillas generalizadas, desarrollaron sintomas claros de manchas amarillas y la infeccion fue del 80 y 20 respectivamente. Hubo transmision por el tuberculo y los sintomas en Rojita y Lopez fueron obvios.