title: Unraveling complex viral infections in cassava (Manihot esculenta Crantz) from Colombia.
abstract: In the Americas, different disease symptoms have been reported in cassava including leaf mosaics, vein clearings, mottles, ring spots, leaf distortions and undeveloped and deformed storage roots. Some viruses have been identified and associated with these symptoms while others have been reported in symptomless plants or latent infections. We observed that reoviruses associated with severe root symptoms (RS) of Cassava Frogskin Disease (CFSD) are not associated with leaf symptoms (LS) observed in the cassava indicator plant 'Secundina'. Neither were these LS associated with the previously characterized Cassava common mosaic virus, Cassava virus X, Cassava vein mosaic virus or phytoplasma, suggesting the presence of additional pathogens. In order to explain LS observed in cassava we used a combination of biological, serological and molecular tests. Here, we report three newly described viruses belonging to the families Secoviridae, Alphaflexiviridae and Luteoviridae found in cassava plants showing severe RS associated with CFSD. All tested plants were infected by a mix of viruses that induced distinct LS in 'Secundina'. Out of the three newly described viruses, a member of family Secoviridae could experimentally induce LS in single infection. Our results confirm the common occurrence of complex viral infections in cassava field-collected since the 1980s.
authors.affiliation: Virology Laboratory, Agrobiodiversity Research Area, International Center for Tropical Agriculture (CIAT), AA 6713 Cali, Colombia.
authors.forename: Monica
authors.initials: M
authors.lastname: Carvajal-Yepes
authors.affiliation: Virology Laboratory, Agrobiodiversity Research Area, International Center for Tropical Agriculture (CIAT), AA 6713 Cali, Colombia.
authors.forename: Cristian
authors.initials: C
authors.lastname: Olaya
authors.affiliation: Virology Laboratory, Agrobiodiversity Research Area, International Center for Tropical Agriculture (CIAT), AA 6713 Cali, Colombia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Lozano
authors.affiliation: Germplasm Health Laboratory, Genetic Resources Program, International Center for Tropical Agriculture (CIAT), AA 6713 Cali, Colombia.
authors.forename: Maritza
authors.initials: M
authors.lastname: Cuervo
authors.affiliation: Virology Laboratory, Agrobiodiversity Research Area, International Center for Tropical Agriculture (CIAT), AA 6713 Cali, Colombia.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Castaño
authors.affiliation: Virology Laboratory, Agrobiodiversity Research Area, International Center for Tropical Agriculture (CIAT), AA 6713 Cali, Colombia. Electronic address: w.cuellar@cgiar.org.
authors.forename: Wilmer J
authors.initials: WJ
authors.lastname: Cuellar
mesh_terms: D060085:Coinfection; D003105:Colombia; D054884:Host-Pathogen Interactions; D052679:Luteoviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D002365:Manihot / Q000821:virology*; D010802:Phylogeny; D058974:Phylogeography; D010849:Picornaviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000821:virology; D018517:Plant Roots / Q000821:virology; D012367:RNA, Viral / Q000235:genetics*; D046830:Tymoviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D014771:Virion / Q000648:ultrastructure
chemical_list: D012367:RNA, Viral
keywords: Alphaflexivirus; Cassava Frogskin Disease; Luteovirus; Mixed virus infections; Reovirus; Secovirus