Occurrence of Cherry green ring mottle virus in Turkey

H.M. Sipahioglu*, M. Usta and M. Ocak

Department of Plant Protection, Faculty of Agriculture, University of Yuzuncu Yil, 65080 Van, Turkey

*hmsipahi@yyu.edu.tr

Accepted for publication 16/02/07

Cherry green ring mottle virus (CGRMV) infects several Prunus species including sweet cherry (P. avium), sour cherry (P. cerasus), oriental flowering cherry (P. serrulata), peach (P. persica)  and apricot (P. armeniaca) in fruit-growing regions throughout North America and Europe (Parker et al., 1976). CGRMV, an unassigned member of the family Flexiviridae, is flexuous filamentous plant RNA virus with a single-stranded, positive-sense RNA genome of approximately 8.4 kb (Zhang et al., 1998). Until recently, routine detection of CGRMV was solely based on graft assay to the woody indicator Kwanzan, the only method accepted by inspection services during quarantine and certification procedures. Since commercial antisera for detection of this virus are not available, serological assays cannot be used for its detection. A reverse transcription polymerase chain reaction (RT-PCR) test has been developed for more sensitive detection (Li & Mock, 2005).

 
Figure 1. Detection of Cherry green ring mottle virus by RT-PCR. Samples loaded on the gel resulted from PCR reactions containing DNA extracted from field collected leaves of cherry trees in orchards (lanes 1-16), leaves of a healthy cherry tree (H), leaves of a confirmed CGRMV-infected (control) cherry tree (P) and a reaction with no input DNA (W). Indicated are the sizes of selected marker bands (lane M), the position of the 366bp fragment amplified from CGRMV and the 200bp fragment of ribulose 1,5-bisphosphate carboxylase (Rbc1).

Leaf samples were collected for the growing season 2006 from 34 sweet cherry trees originating from the eastern Anatolia region of Turkey. Total RNA was extracted from these samples using a modified protocol based on silica-capture (Foissac et al., 2001). RT-PCR detection of CGRMV was carried out according to Foissac et al., (2001) but including an additional internal control; amplifying a fragment of the chloroplast gene ribulose 1,5-bisphosphate carboxylase. CGRMV was identified in 11 of the 34 sweet cherry samples, yielding a PCR product of the expected size (366 bp). The expected fragment (200bp) of the internal PCR control was also amplified from all cherry samples analyzed (Fig. 1).

PCR products from six cherry trees were directly sequenced (accession numbers EF174471, EF182749, EF182750, EF182752, EF182753, EF182754) and showed over 85% nucleotide sequence identity to sequences of other CGRMV isolates in the databases. This is the first record of the presence of CGRMV in Turkey and provides a starting point for investigation of the incidence of the virus in sweet cherry orchards of Turkey.

Acknowledgements

The authors are grateful to Dr. E. Koban and Dr. R. Yilmaz from Middle East Technical University Molecular Biology and Biotechnology R&D Center for their assistance with the sequencing of CGRMV isolates.

References

Foissac X, Svanella-Dumas L, Dulucq MJ, Gentit P, Candresse T, 2001. Polyvalent detection of fruit tree tricho, capillo and foveaviruses by nested RT-PCR using degenerated and inosine containing primers (PDO RT-PCR). Acta Horticulturae 550, 37-43.

Li R, Mock R, 2005. An improved reverse transcription-polymerase chain reaction (RT-PCR) assay for the detection of two cherry flexiviruses in Prunus spp. Journal of Virological Methods 129, 162–169.

Parker KG, Fridland PR, Gilmer GM, 1976. Green ring mottle. In Virus Diseases and Noninfectious Diseases of Stone Fruit in North America, US Department of Agriculture, Agriculture Handbook no. 437. pp. 193–199.

Zhang YP, Kirkpatrick BC, Smart CD, Uyemoto JK, 1998. cDNA cloning and molecular characterization of cherry green ring mottle virus. Journal of General Virology 79, 2275–2281.

The British Society for Plant Pathology