Submitted to: Scientia Agricola
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/14/2005
Publication Date: 1/20/2006
Citation: Hammond, R., Bedendo, I. 2006. Molecular confirmation of maize rayado fino virus as the brazilian corn streak virus. Scientia Agricola. 62:601-603. Interpretive Summary: Corn stunt, a disease of corn that occurs in the Southern United States, and Central and South America, is caused by a complex of three disease agents, one of which is a virus known as rayado fino. In Brazil, a related virus is associated with a severe disease of corn, but the identity of the virus was in question. We characterized the virus from Brazil at the molecular level and found it to be a strain of rayado fino virus. Knowledge of the disease agent will allow use of appropriate control measures to reduce crop losses. This report will be of interest to an international audience of plant pathologists and agronomists.
Technical Abstract: Maize rayado fino virus (MRFV), present in various countries in Latin America, has shown similarities to the corn streak virus that occurs in Brazil, regarding pathogenic, serological and histological characteristics. In the current report, both viruses were molecularly compared to confirm the similarities between them. MRFV was identified by nucleic acid hybridization in samples of maize tissues exhibiting symptoms of “corn stunt” disease, collected from two Brazilian States – São Paulo and Minas Gerais. The coat protein gene and 3’non-translated region of MRFV were amplified from infected tissues by reverse transcription-polymerase chain reaction (RT-PCR) using MRFV-specific primers, and were characterized by nucleotide sequence and phylogenetic analysis of the cloned PCR products. Phylogenetic analysis of the relationships between the Brazilian isolates and isolates obtained from Latin America and the United States reveals a close relationship to isolates from Brazil, Peru and Bolivia. The results support the proposal that the Brazilian corn streak virus be regarded as an isolate of MRFV and provide evidence for the presence of MRFV in “corn stunt’ disease in Brazil.