Genetic diversity among viruses associated with sugarcane mosaic disease in Tucumán, Argentina.

PERERA, FILIPPONE, RAMALLO, CUENYA, GARCÍA, PLOPER Y CASTAGNARO

PHYTOPATHOLOGY

APS Press

Lugar: St. Paul, MN 55121 U.S.A.; Año: 2009 vol. 99 p. 38 - 49

0031-949X

Sugarcane leaves with mosaic symptoms were collected in 2006-2007 in Tucumán (Argentina) and analyzed by RT-PCR-RFLP and sequencing of a fragment of the Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV) coat protein (CP) genes. SCMV was detected in 96.6% of samples with 41% showing the RFLP profile consistent with strain E. The remaining samples produced eight different profiles that did not match other known strains. SCMV distribution seemed to be more related to sugarcane genotype than to geographical origin, and sequence analyses of CP genes showed a greater genetic diversity compared to other studies. SrMV was detected in 63.2% of samples, and most of these were also infected by SCMV, indicating that unlike other countries and other Argentinean provinces, where high levels of co- infection are infrequent, co-existence is common in Tucumán. RFLP analysis showed the presence of SrMV strains M (68%) and I (14%), while co-infection between M and H strains was present in 18% of samples. Other SCMV subgroup members and the Sugarcane streak mosaic virus (SCSMV) were not detected. Our results also showed that sequencing is currently the only reliable method to assess SCMV and SrMV genetic diversity, as RT-PCR-RFLP may not be sufficiently discriminating.