Archivio Journal of Plant Pathology

Abstract:

Tobacco mosaic virus (TMV) is distributed worldwide in all areas where horticultural crops are grown. In 2011, commercial cabbage (Brassica oleracea var. capitata) fields in the Savejbolagh district of Alburz province in Iran showed mosaic and malformations on young leaves. Based on the symptoms and previous virus survey outputs in the region (Alishiri et al., 2013), the involvement of tobamoviruses in disease aetiology was suspected. A total of 55 symptomatic cabbage leaf samples were collected from different fields and tested by DAS-ELISA using specific TMV antisera (Bioreba, Switzerland). TMV was detected in 58% of the samples tested. Its presence was confirmed by RT-PCR using specific primers designed in the coat protein gene (Letschert et al., 2002) with amplification of a 694 bp fragment from ELISA-positive but not from ELISA-negative control samples. The RT-PCR product of a TMV isolate was sequenced and the nucleotide sequence was deposited in GenBank as accession No. KF527475. BLAST analysis showed 90% and 100% identity with the coat protein gene of other TMV isolates (AF516913, AJ429078, AY360447, HE818417) at the nucleotide and amino acid levels, respectively. A host range trial using infected cabbage leaf extracts as inoculum revealed characteristic TMV symptoms on mechanically inoculated Chenopodium amaranticolor, Nicotiana tabacum cv. Samsun and Solanum lycopersicum. TMV isolates induced chlorotic local lesions on inoculated leaves of C. amaranticolor and systemic mosaic and malformations in tomato and tobacco plants. Symptomatic herbaceous hosts tested positive for TMV antibodies in ELISA. To the best of our knowledge, this is the first report of TMV on cabbage in Iran.