Location: National Germplasm Resources LaboratoryTitle: Sugarcane streak mosaic virus detected in Louisiana
|MALAPI-WIGHT, MARTHA - Animal And Plant Health Inspection Service (APHIS)|
Submitted to: Sugar Journal
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2018
Publication Date: 6/1/2018
Citation: Mollov, D.S., Grinstead, S.C., Hale, A.L., Malapi-Wight, M., Grisham, M.P. 2018. Sugarcane streak mosaic virus detected in Louisiana. Sugar Journal. 81:19.
Technical Abstract: Sugarcane mosaic disease (SMD) is an economically important problem in sugarcane production areas worldwide. The causal agents for SMD include Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), and Sugarcane streak mosaic virus (SCSMV). Both SCMV and SrMV occur in the United States and the latter is reported as the primary cause of SMD in Louisiana. SCSMV has only been reported in several Asian countries including Bangladesh, India, Pakistan, Sri Lanka, Thailand, Vietnam, China, Japan, Indonesia, Malaysia, and Iran and has never been reported in the U.S. In Louisiana, two Saccharum spontaneum accessions with pronounced mosaic symptoms were observed at the sugarcane research station in Houma. Samples from both were submitted to the National Germplasm Resources Laboratory for investigation. Total RNA was extracted from pooled leaves and two cDNA libraries were subjected to high throughput sequencing (HTS) using Illumina technologies. A total of 16 million single-end reads were obtained from each sample. Reads were assembled using CLC Genomics Workbench 11.0. and a single 10 kb contig representing the complete genome of SCSMV was obtained from each sample. These contigs encode a single polyprotein consisting of 3,130 amino acids. Over 4.5 million HTS reads from the first sample and 6 million HTS reads from the second sample were mapped to the assembled SCSMV genomes. The genome coverage was 37,496 X and 47,076 X, for the two samples. BLASTP analyses revealed 98% and 99% identities between the contigs and NCBI Genbank SCSMV accessions. Both S. spontaneum accessions have been quarantined to minimize a potential threat. PCR primers were designed and survey efforts are being conducted to assess if this is an isolated incident, and to monitor for potential spread of this exotic virus to the U.S. sugarcane industry.