Wheat: A New Natural Host for the Mal De Río Cuarto Virus in the Endemic Disease Area, Río Cuarto, Córdoba Province, Argentina

Abstract

The fijivirus known as “Mal de Río Cuarto” that affects corn is endemic to the area of Río Cuarto, Cordoba Province, Argentina. One of the preferred species for the development of its vector, the insect Delphacodes kuscheli Fennah, is wheat. In this area, wheat plants with deformed leaves, spikes and spikelets, shortened internodes, leaves with serrated borders, and sterile spikelets were detected, suggesting the possibility that Mal de Río Cuarto Virus could also be infecting this crop. Samples originating in Río Cuarto, Sampacho, and La Carlota (Córdoba Province) that showed symptoms, were analyzed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), polyacrylamide gel electrophoresis, and electron microscopy, confirming, for the first time, the occurrence of the disease in wheat. The frequency of the disease was assessed in random samples from 14 wheat plots located in the Department of Río Cuarto (Córdoba Province). The samples were analyzed using the DASELISA immunoenzymatic technique, and the disease was detected in the majority of the fields assessed, with levels of incidence that ranged between 2.5 and 24%. We must be aware of the presence of this virus in the wheat crop, where it appears to play a double role in the epidemiology of the disease, acting both as a virus reservoir and as a preferred host for the development of populations of the vector virus, D. kuscheli.