Location: National Germplasm Resources LaboratoryTitle: First report of Catharanthus mosaic virus in Mandevilla in the United States Author
|Guaragna, Mary Ann|
|Rezende, Jorge Alberto M|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2014
Publication Date: 10/5/2014
Citation: Mollov, D.S., Guaragna, M., Lockhart, B., Rezende, J., Jordan, R. 2014. First report of Catharanthus mosaic virus in Mandevilla in the United States. Plant Disease. 99:165. Interpretive Summary: Mandevilla is an ornamental tropical vine popular for its bright and attractive flowers. We received and analyzed samples from Minnesota and Florida nurseries with disease symptoms such as leaf yellowing and deformation, premature leaf senescence and vine dieback. Filamentous virus particles were observed in an electron microscope using partially purified preparations from symptomatic leaves. Nucleic acid based assays confirmed the virus is in the potyvirus group and sequencing revealed it is Catharanthus mosaic virus (CatMV). The identity of the virus was also confirmed by an antigen-antibody assay using CatMV-specific antiserum from Brazil. CatMV has previously been reported only in periwinkle (Catharanthus roseus) in Brazil. Based on our analyses we identify this virus as a U.S. Mandevilla isolate of CatMV. To our knowledge this is the first report of CatMV in both the United States and in the plant mandevilla. This information will be useful to ornamental nurseries, public and private plant disease diagnostic clinics, and other scientists who study ornamental viruses.
Technical Abstract: Mandevilla (Apocynaceae) is an ornamental tropical vine popular for its bright and attractive flowers. During 2012-2013 twelve Mandevilla sp. samples from Minnesota and Florida nurseries were submitted for analysis at the University of Minnesota Plant Disease Clinic. Plants showed mosaic symptoms, leaf deformation, premature leaf senescence and vine dieback. Filamentous virus particles with modal lengths 700-900 nm were observed by transmission electron microscopy (TEM) in partially purified preparations from symptomatic leaves. No other virus particles were observed in these samples, nor were any observed in non-symptomatic samples. Total RNA (Qiagen) was extracted from a Mandevilla 'Sunmandeho' Sun Parasol® Giant White plant. Potyvirus was detected in this sample using universal primers by reverse transcription (RT)-PCR. The amplified product was the expected ~1.7 kb, corresponding to the partial nuclear inclusion body gene, the coat protein (CP) gene and the 3’ end untranslated region. The RT-PCR amplicon was cloned (NEB), sequenced and the 1720 bp consensus sequence was deposited in GenBank (Accession number KM243928). NCBI BLAST analysis at the nucleotide level revealed highest identity (83%) with an isolate of Catharanthus mosaic virus (CatMV) from Brazil, (accession number DQ365928). Pairwise analysis of the predicted 256 amino acid CP revealed 91% identity with the CatMV Brazilian isolate (ABI94824) and 68% or less identity with other potyviruses. Two viruses are usually considered the same species if their CP amino acid sequences are greater than 80% identical. Serological analysis of infected samples using a CatMV specific antiserum resulted in positive indirect ELISA reactions. CatMV has been previously reported in periwinkle (Catharanthus roseus) in Brazil. Based on the analyses by TEM, RT-PCR, nucleotide and amino acid sequence identities and serological reactivity, we identify this virus as a U.S. Mandevilla isolate of CatMV. To our knowledge this is the first report of Catharanthus mosaic virus both in the United States and in Mandevilla.