Genetic Diversity Among Viruses Associated with Sugarcane Mosaic Disease in Tucumán, Argentina

M. F. PERERA, ; FILIPPONE, M. P.; RAMALLO, C. J.; CUENYA, M.I.; GARCIA , M.L.; PLOPER, D.L.; CASTAGNARO, A.P.

PHYTOPATHOLOGY

AMER PHYTOPATHOLOGICAL SOC

Año: 2009 p. 38 - 49

0031-949X

Sugarcane leaves with mosaic symptoms were collected in 2006?07 inTucumán (Argentina) and analyzed by reverse-transcriptase polymerasechain reaction (RT-PCR) restriction fragment length polymorphism(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 RFLPprofile consistent with strain E. The remaining samples produced eightdifferent profiles that did not match other known strains. SCMV distributionseemed to be more related to sugarcane genotype than to geographicalorigin, and sequence analyses of CP genes showed a greatergenetic diversity compared with other studies. SrMV was detected in63.2% 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 commonin Tucumán. RFLP analysis showed the presence of SrMV strains M(68%) and I (14%), while co-infection between M and H strains waspresent in 18% of samples. Other SCMV subgroup members and theSugarcane streak mosaic virus (SCSMV) were not detected. Our resultsalso showed that sequencing is currently the only reliable method toassess SCMV and SrMV genetic diversity, because RT-PCR-RFLP maynot be sufficiently discriminating.