First Report of Cucumber mosaic virus on Lavandula angustifolia in Poland

Lavandula angustifolia Mill. (synonym Lavandula officinalis Chaix), belonging to the Lamiaceae family, is a plant that is widespread in Mediterranean countries. The species is widely grown as an ornamental crop in Poland. Currently, only Alfalfa mosaic virus (AMV) is known to infect L. latifolia × L. officinalis in Italy (3). In the spring of 2005, we observed yellow mottling, leaf deformation, and growth reduction of L. angustifolia plants from the Agricultural Academy of Kraków collection of medicinal herbs and spices. Mechanical inoculation of a range of indicator plant species, Chenopodium quinoa, Cucumis sativus, Datura strammonium, Nicotiana glutinosa, N. tabacum cv. Xanthi, Lycopersicon esculentum, and Spinacia oleracea, with sap from symptomatic L. angustifolia plants resulted in symptoms typical of Cucumber mosaic virus (CMV). Chlorotic local lesions and systemic mosaic were observed after a few days on the tested plant species. However, local lesions did not develop on inoculated C. sativus cotyledons. A lack of systemic infection on Chenopodium quinoa excluded infection by AMV. The sap from symptomatic N. tabacum cv. Xanthi leaves contained spherical virus particles of 29 nm in diameter when examined with electron microscopy. Symptomatic N. tabacum cv. Xanthi leaves were positive for CMV in a double-antibody-ELISA using commercial CMV antiserum (Loewe Biochemica GmbH, Sauerlach, Germany). Total RNA was extracted from infected N. tabacum cv. Xanthi plants by the phenolchloroform method. Reverse transcription-PCR was carried out using specific primers CMVF 5'-CCCACAGGTAGAATCAAAT-3' and CMVR 5'-ATGGACAAATCTGAATCAAC-3' (1). The 367-bp amplicon representing a portion of the coat protein gene located in RNA3 was cloned into pGEM-T Easy Vector (Promega, Madison, WI) and two clones were sequenced. The fragment sequence (Accession No. EU303304) was compared with homologous sequences of CMV isolates from the GenBank database. Multiple sequence alignment was performed by using Mega 4 (Center for Evolutionary Functional Genomics, Tempe, AZ) (4) and revealed 99% nucleotide and amino acid identity between the Polish isolate of CMV-PL and the RT67 (subgroup II) isolate from the Netherlands (2) To our knowledge, this is the first report on the occurrence of CMV on Lavandula angustifolia Mill. in Poland or worldwide. References: (1) N. Borodynko et al. Prog. Plant Protect. 44:604, 2004. (2) Z. Deyong et al. J Virol. Methods 123:101, 2005. (3) L. Giunchedi et al. Phytopathol. Mediterr. 11:74, 1972. (4) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007.