Tulip virus X (TVX) was first isolated from tulips in Scotland (3). TVX is now found in all tulip-growing areas throughout the Netherlands, and other countries including Japan and New Zealand (2). In Poland, tulips are grown for bulb production in an estimated area of 450 ha. Since tulips are very popular during the winter season, bulbs are imported for forcing from the Netherlands. In spring 2011, symptoms typical of TVX infection were observed in field-grown ‘Strong Gold’ tulips in two farms in Mazovia Province. Leaves showed chlorotic and white, elongated streaks and spots, which are typical symptoms of TVX infection. Symptomatic leaves of four tulip plants tested positive by using TVX polyclonal antiserum in a double-antibody sandwich-ELISA assay (Bulb Quality Support B.V., Lisse, The Netherlands), whereas two plants were also infected with Tulip breaking virus. Total RNA was extracted from leaves of the same four symptomatic tulips with a silica capture method (1) and the extracts were used in a reverse transcription-PCR. Primers for the detection of TVX as well as cycling conditions were as previously reported (4). Primer pairs TVX1F-TVX1R and TVX2F-TVX2R are specific for a 219-bp fragment of the RNA-dependent RNA polymerase gene and a 189-bp fragment of the triple gene block gene-1, respectively. Amplified PCR products of the expected sizes were purified and sequenced (Genomed S.A., Warsaw, Poland). Sequence analyses showed that both fragments had 99.5 to 100% sequence identities at the nucleotide level with Genbank Accession No. AB066288. Two of the 219-bp amplicon sequences, varied by one nucleotide resulting in an amino acid substitution, were deposited in GenBank under Accession Nos. JN411683 and JN411684. To our knowledge, this is the first report of TVX in tulip in Poland. The occurrence of this virus could be important for bulb and flower production, particularly in the case of further spread because the virus can cause severe symptoms that make flowers unmarketable.
References: (1) R. Boom et al. J. Clin. Microbiol. 28:495,1990. (2) P. J. M. Knippels. Acta Hortic. (ISHS) 886:147, 2011. (3) W. P. Mowat. Ann. Appl. Biol. 101:51, 1982. (4) I. E. Tzanetakis et al. Plant Pathol. 54:562, 2005.