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Poster: Diseases of Plants: Disease Detection & Diagnosis


Nucleotide sequence and genome organization of a novel Panicovirus from Bermuda grass
M. TAHIR (1), B. Lockhart (2), S. Grinstead (1), D. Mollov (1) (1) USDA-ARS, U.S.A.; (2) University of Minnesota, Department of Plant Pathology, U.S.A.

Bermuda grass (Cynodon dactylon) is widely used in tropical and subtropical areas for golf greens, athletic fields, and landscapes. Samples of Bermuda grass displaying symptoms of decline were tested at the University of Minnesota plant virology lab. Spherical virus particles (28-30 nm) were observed by transmission electron microscopy. Total RNA was extracted and sent for Next Generation Sequencing (NGS) on an Illumina platform. Contigs were assembled using CLC Workbench, and analyzed using BLAST searches against reference genomes. A contig of about 4 kb contained four predicted ORFs in an arrangement typical of viruses in the family Tombusviridae. Overlapping primer pairs were designed from the consensus sequence for RT-PCR verification and sequence confirmation. All amplicons were cloned and the resulting sequences matched the original NGS contig. Amino acid sequence comparisons of the putative replicase (RdRp) and movement and coat proteins (CP) showed sequence similarities in the range of 37-66% compared to Thin paspalum asymptomatic virus, Cocksfoot mild mosaic virus, and Panicum mosaic virus. Phylogenetic analyses using the CP and RdRP of this newly identified virus place it in the genus Panicovirus. The sequence of this Bermuda grass virus is sufficiently different from other viruses to conclude it is a new member of the genus Panicovirus, family Tombusviridae.