Alfalfa dwarf disease, a viral complex affecting alfalfa crop in Argentina.

VERÓNICA TRUCCO; NICOLÁS BEJERMAN; SOLEDAD DE BREUIL; DARIEL CABRERA MEDEROS; SERGIO LENARDON; FABIÁN J. GIOLITTI

Córdoba

Congreso; SECOND WORLD ALFALFA CONGRESS; 2018

Instituto Nacional de Tecnología Agropecuaria

Alfalfa (Medicago sativa L.) is considered the most important forage crop in Argentina and an essential component of bovine meat and milk production. In 2010, a new viral disease, named alfalfa dwarf disease-ADD, was identified in Argentina. The symptoms include severe plant stunting and leaves with decreased size, distortion, chlorosis and the presence of vein enations and papillae on the abaxial surface. Initial field assays indicated that ADD presented incidences higher than 50%, yield decreases of dry mass of up to 30% and significantly reduced crop life. Plants infected with ADD were found to be co-infected with Alfalfa mosaic virus (AMV) and Alfalfa dwarf cytorhabdovirus (ADV). Subsequently, other three viruses were detected in the same plants: Bean leafroll virus (BLRV), Alfalfa enamovirus-1 (AEV-1) and Alfalfa leaf curl virus (ALCV). So far, these five viruses (collectively named as Argentine Alfalfa Viruses = AAV) were detected in alfalfa plants, with ADV and AEV-1 being virus species described for the first time worldwide. Our objective was to generate data to elucidate the situation of the viral disease complex in this crop and the relative importance of each component of the disease complex.