Location: National Germplasm Resources LaboratoryTitle: The weed Sorghum almum is a putative alternative host of sugarcane infecting viruses in Florida
|Rott, Philippe - University Of Florida|
|Boukari, Wardatou - University Of Florida|
|Wei, Chunyan - University Of Florida|
|Mulandesa, Eva - University Of Florida|
|Hincapie, Martah - University Of Florida|
|Kaye, Caludia - Us Sugar Corporation|
Submitted to: Sugar Journal
Publication Type: Abstract Only
Publication Acceptance Date: 4/16/2017
Publication Date: 6/1/2017
Citation: Rott, P., Boukari, W., Wei, C., Mulandesa, E., Hincapie, M., Kaye, C., Mollov, D.S. 2017. The weed Sorghum almum is a putative alternative host of sugarcane infecting viruses in Florida. Sugar Journal. 80:14-16.
Technical Abstract: Sorghum almum or Columbus grass is a common weed growing in the Everglades Agricultural Area (EAA). In recent surveys for alternative hosts of sugarcane yellow leaf virus (SCYLV), 123 out of 141 (87%) plants of S. almum tested positive for this virus by tissue blot immunoassay (TBIA) using polyclonal antibodies raised against SCYLV. However, the virus was not detected in 10 out of 25 TBIA positive samples by reverse transcription-polymerase chain reaction (RT-PCR) or semi-nested RT-PCR using SCYLV primers. High throughput sequencing (HTS) of one of these RT-PCR negative plants revealed the presence of a new marafivirus. The discovery of this new marafivirus was validated by RT-PCR and sequencing with primers developed using the HTS data. Therefore, there may be cross-reactivity in our serological assay between the SCYLV polyclonal antibodies and the marafivirus. The 141 S. almum plants from the EAA did not show symptoms that could be attributed to either SCYLV or the marafivirus. However, patterns of contrasting shades of green were observed on leaves of a few plants (<10%). Examination of preparations of symptomatic leaves by transmission electron microscopy revealed the presence of filamentous virus particles (about 750 nm long). These particles were subsequently determined to be sugarcane mosaic virus (SCMV) by RT-PCR and sequencing. Thus, our investigations into the incidence of SCYLV in S. almum revealed not only occurrence of SCMV, but resulted also in the discovery of a new marafivirus in this host. Pathogenicity in sugarcane of these three viruses needs to be verified in order to determine the importance of S. almum as a reservoir for sugarcane infecting viruses in Florida.