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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #129364
Title: ISOLATION AND CHARACTERIZATION OF A CARMO-LIKE VIRUS FROM CALIBRACHOA PLANT

Author
item Liu, Hsing Yeh
item Sears, John
item MORRISON, R - SAKATA SEED AMER.,SALINAS

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary: Calibrachoa is an important new horticultural plant. The genus Calibrachoa is closely related to the well-known genus Petunia. Spherical virus particles c. 29 to 31 nm in diameter were isolated from Calibrachoa plants showing leaf mottling and chlorotic blotch symptoms. Virions contained a single species of single-stranded RNA of approximately 4.0 kb and a single capsid protein of approximately 41 kDa. The double-stranded RNA pattern consistently revealed one major band of about 4.0 kbp, and three subgenomic dsRNA of c. 3.1, 1.6, and 1.3 kbp. A part of the highly conserved motif of carmovirus-related RNA-dependent RNA polymerase gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into pGEM-T Easy vector. The cloned cDNA sequencing data revealed 94% similarity with Carnation mottle carmovirus (CarMV). However, the Calibrachoa virus and CarMV were serologically distinct. We concluded that the recently observed Calibrachoa disease is caused by a previously undescribed carmovirus. We propose to name this virus Calibrachoa mottle virus (CbMV). Commercial reproduction of Calibrachoa and the maintenance of genetic mother stock are done by means of vegetative propagation, as reproduction through seed is difficult. CbMV was easily mechanically transmitted. Thus, CbMV can be readily propagated along with its host. Our data showed that indirect ELISA and specific polyclonal antibodies will be useful for the rapid identification and indexing of Calibrachoa for CbMV. ELISA should be an efficient method for the production and maintenance of virus-free mother stock and commercial planting stock in a healthy nursery management program.

Technical Abstract: Calibrachoa La Llave & Lexarza (Solanaceae Jiss.) is an important new landscaping plant. The genus Calibrachoa is closely related to the well- known genus Petunia Jussieu. Spherical virus particles c. 29 to 31 nm in diameter were isolated from Calibrachoa plants showing leaf mottling and chlorotic blotch symptoms. The virus was mechanically transmitted to Chenopodium quinoa, C. capitatum, Nicotiana benthamiana, and N. clevelandi plants, but was not transmitted by green peach aphid (Myzus persicae), sweetpotato whitefly (Bemisia tabaci), silverleaf whitefly (B. argentifolii), greenhouse whitefly (Trialeurodes vaporarium), or banded- wing whitefly (T. abutilonea). Virions contained a single species of single-stranded RNA of approximately 4.0 kb and a single capsid protein of approximately 41 kDa. The double-stranded RNA pattern consistently revealed one major band of about 4.0 kbp, and three subgenomic dsRNA of c. 3.1, 1.6, ,and 1.3 kbp. The virus-infected plants reacted with a homologous polyclona antiserum in indirect enzyme-linked immuno-sorbent assay. A part of the highly conserved motif of carmovirus-related RNA-dependent RNA polymerase gene was amplified by reverse transcription-polymerase chain reaction (RT- PCR) and cloned into pGEM-T Easy vector. The cloned cDNA sequencing data revealed 94% similarity with Carnation mottle carmovirus (CarMV). However, the Calibrachoa virus and CarMV were serologically distinct. We concluded that the recently observed Calibrachoa disease is caused by a previously undescribed carmovirus. We propose to name this virus Calibrachoa mottle virus (CbMV).