Author
HALGREN, A - OREGON STATE UNIVERSITY | |
TZANETAKIS, I - OREGON STATE UNIVERSITY | |
Martin, Robert |
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/5/2006 Publication Date: 1/3/2007 Citation: Halgren, A., Tzanetakis, I.E., Martin, R.R. 2007. Identification, characterization, and detection of a virus associated with decline symptoms in black raspberry. Phytopathology. 97:44. Interpretive Summary: A serious disease was observed in black raspberry (Rubus occidentalis) in Oregon in the last decade. Plants showing mosaic symptoms declined rapidly and in many cases died in a short time period. A virus was associated with the disease symptoms and was further characterized by sequencing and identification of vectors and transmission properties. The virus has two RNAs and is most similar to Strawberry mottle virus. It is transmitted by the large raspberry aphid (Amphorphora agathonica) and the green peach aphid (Myzus persicae). A diagnostic test based on polymerase chain reaction (PCR) was developed and used to identify the virus in transmission studies with the two aphids listed above. The aphids can acquire the virus from infected plants in as little as one minute and are able to transmit the virus immediately after acquisition. Transmission is very efficient and even low numbers of aphids in the field can result in rapid spread of the virus. Technical Abstract: A serious disease was observed in black raspberry (Rubus occidentalis) in Oregon in the last decade. Plants showing mosaic symptoms declined rapidly and in many cases died in a short time period. Double-stranded RNA extraction from symptomatic black raspberry revealed the presence of two high MW bands which were cloned and sequenced. Sequence analysis disclosed the presence of a novel virus that was named Black raspberry decline associated virus (BRDaV). The complete sequences of the two genomic RNAs, excluding the 3´ polyadenosine tails, are 7581 and 6364 nucleotides, respectively. The genome organization was identical to that of Strawberry mottle virus, a member of the Sadwavirus genus. The C´ terminus of the RNA 1 polyprotein is unique to the genus Sadwavirus, with homology to AlkB-like protein domains, suggesting a role in repair of alkylation damage. An RT-PCR test was designed for the detection of BRDaV from Rubus tissue, and tests revealed that BRDaV was consistently associated with the observed decline symptoms. The virus was vectored non-persistently by the large raspberry and the green peach aphids. Phylogenetic analysis based on conserved motifs of the protease, helicase and polymerase regions indicate that BRDaV belongs to the Sadwavirus genus. |