Oral Technical Session: Virology

107-O

Eight new viruses identified in bioenergy switchgrass.
B. O. AGINDOTAN (1), L. L. Domier (1), M. E. Gray (1), C. A. Bradley (1)
(1) University of Illinois, Urbana, IL, U.S.A.

Panicum virgatum (switchgrass), a potential bioenergy crop, was investigated for virus infections that could reduce its biomass yield. In addition to Barley yellow dwarf viruses (BYDVs), Sugarcane mosaic virus (SCMV), Panicum mosaic virus (PMV), and recently, Switchgrass mosaic virus (SwMV), were reported to infect the crop. To determine if other RNA viruses infect switchgrass, five young leaves were collected from 18 switchgrass varieties with different foliar symptoms ranging from necrotic spots to mosaic from a five-year old switchgrass plot. Pieces (about 3-cm) were cut from the tips of symptomatic leaves and pooled. To enrich for viruses, virus particles were partially purified from 5 g of the ground pooled leaf tips. Total RNA extracted from the preparation was treated with DNase 1, reverse transcribed, and high-throughput sequenced. Eight new RNA viruses and one unexpected DNA virus were identified. The replicase or coat protein amino acid sequences of the eight viruses were 30% to 52% identical to the most closely related poleroviruse, tenuivirus, ctyorhabdovirus, ourmavirus, foveavirus, fijivirus, cripavirus or mastrevirus in GenBank. The viruses were detected in 5 to 18 of the original 18 varieties of switchgrass and are being further characterized.