Submitted to: Acta Horticulture Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/1998
Publication Date: N/A
Interpretive Summary: Prunus necrotic ringspot virus (PNRSV) occurs worldwide and is a serious pathogen of many woody plant species, including sweet and sour cherry, peach, rose, apple, and plum. Sweet cherry trees infected with PNRSV exhibit a range of symptoms from none, to a severe disease which affects fruit quality and yield, and overall plant vigor. The type of symptoms expressed in a diseased plant is dependent upon the virus strain or isolate infecting the tree. These strains are serologically indistinguishable, severely limiting enzyme-linked immunosorbent assays (ELISA) as a tool for identifying severe strains to reduce field spread of the disease. We have developed strain-specific polymerase chain reaction (PCR) assays to rapidly distinguish the strains present in budwood of infected trees. The method is of practical use to scientists, extension services, action agencies (APHIS), and quarantine facilities as an aid in reducing field spread of the disease.
Technical Abstract: Nucleotide sequence alignment of a 1.65 kb PCR product obtained from RNA3 of several biologically distinct PNRSV sweet cherry isolates revealed correlations between symptom type and the nucleotide and amino acid sequences of the 3a (putative movement protein) and 3b (coat protein) open reading frames (Hammond and Crosslin, 1998). Based upon this analysis, reverse transcription-polymerase chain reaction (RT-PCR) assays have been developed that can distinguish between symptom types. The results of PCR amplification using type-specific primers that amplify a portion of the coat protein gene show that the primer-selection procedure developed for PNRSV constitutes a reliable method of viral strain discrimination in cherry.