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ARS Home » Research » Publications at this Location » Publication #232361
Title: First Report of Tobacco Rattle Virus in Peony in Alaska

Author
item ROBERTSON, NANCY
item BROWN, KATHRYN
item WINTON, LORETTA
item HOLLOWAY, P - UNIV. OF ALASKA

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2009
Publication Date: 6/1/2009
Citation: Robertson, N.L., Brown, K.L., Winton, L.M., Holloway, P.S. 2009. First Report of Tobacco Rattle Virus in Peony in Alaska. Plant Disease. 93(6):675.

Interpretive Summary: Peonies (Paeonia sp.) are highly valued for their large showy flowers in home gardens and commercially in the cut flowers industry. In 2007, scattered peony (Paeonia lactiflora ‘Sarah Bernhardt’) plants cultivated on small plots at the University of Alaska Experimental Station in Fairbanks, Alaska contained distinct leaf ringspot patterns. Leaves from symptomatic plants were collected and assayed for viruses. Reverse transcriptase-polymerase chain reaction (RT-PCR) with specific primers for Tobacco rattle virus (TRV) generated fragments of expected size with sequences that closely matched conserved regions on TRV RNA 1. Mechanical transmission of extracted virus occurred in several plant species in host range studies that were similar to TRV. Rod-shaped particles that resembled TRV with a distinct central canal were observed by electron microscopy. It was concluded that at least two peony plants were infected with TRV, tentatively naming the isolate TRV-Peony. Documentation of TRV in peonies is especially important to help avoid distribution of virus-infected vegetative propagation material. This is the first report of TRV in Alaska.

Technical Abstract: In 2007, scattered peony (Paeonia lactiflora ‘Sarah Bernhardt’) plants cultivated on plots at the University of Alaska Experimental Station in Fairbanks, Alaska, contained distinct leaf ringspot patterns. Leaf samples from symptomatic plants were collected in early July (6 plants) and late September (20 plants). Leaf samples were assayed using a general protocol for plant viral extraction, purification and RT-PCR. An expected ~600-bp fragment was amplified using a nested set of primers designed for Tobacco rattle virus (TRV) detection of the 16 kDa protein gene on RNA1, and directly sequenced. Blast searches in GenBank revealed closest relationship to TRV isolates reaching 95 % nucleotide (nt) identity. Additional sets of primers were used to generate overlapping fragments encoding 29 kDa and 16 kDa protein genes on the 3'-end of RNA1. The resulting 1422 nucleotide (nt) segment had 93 to 94 percent nt identity to other TRV isolates: -ORY, -PpK20, -Pp085, and -SYM. Specific comparisons with the 29 kDa gene ranged from 90 to 92 % (nt) and 96 to 98 % (aa, amino acid), and with the 16 kDa gene from 95 to 96 % (nt) and 94 to 97 % (aa). Biological features of the isolated virus included: mechanical transmission to an experimental plant host range, rod-shaped particles with a distinct central canal by electron microscopy, and two RNA species about 7.5 kb and 3.4 kb presumed to be RNA1 and RNA2, respectively, by electrophoresis. Based on the given biological and molecular data, we have conclusively determined that at least two of the peony plants were infected with TRV, and have tentatively named the isolate TRV-Peony. This is the first report of TRV in Alaska. Documentation of TRV in peonies is especially important to help avoid distribution of virus-infected vegetative propagation material.