First Report of Beet soilborne virus in Poland.

Beet necrotic yellow vein virus (BNYVV), the casual agent of rhizomania disease, was identified in sugar beet plants from several fields in the Wielkopolska Region of Poland (1). In greenhouse studies, sugar beets were grown in the soil from one of these fields to bait soilborne viruses. Of 200 sugar beet plants, three developed symptoms of vein clearing, vein banding, and mosaic. Crude sap from symptomatic plants was used for mechanical inoculation of various plants species. In Chenopodium quinoa, C. amaranticolor, and Tetragonia expansa only local lesions were observed. Electron microscope examination of negatively stained leaf-dip preparations from symptomatic sugar beet plants showed a mixture of rod-shape particles from 70 to 400 nm long. Using double-antibody sandwich enzyme-linked immunosorbent assay tests, two symptomatic sugar beet plants gave positive reactions with antiserum against BNYVV (Bio-Rad, Hercules, CA) and a third plant gave a positive reaction with antisera against BNYVV and Beet soilborne virus (BSBV). Total RNA was extracted from roots and leaves of the symptomatic plants and used in a multiplex reverse transcription-polymerase chain reaction (mRT-PCR) assay. Specific primers were designed to amplify a fragment of the RNA1 for BSBV and RNA2 for BNYVV and Beet virus Q (BVQ) (2). Two mRT-PCR products amplified with the primers specific to BNYVV and BSBV were obtained and sequenced. A 274-nt amplicon sequence (GenBank Accession No. DQ012156) had 98% nucleotide sequence identity with the German BNYVV isolate F75 (GenBank Accession No. AF19754) and a 376-nt amplicon sequence (GenBank Accession No. AY999690) had 98% nucleotide and 98% amino acid sequence identity with the German BSBV isolate (GenBank Accession No. Z97873). The Polish BSBV isolate had 88% nucleotide and 62% amino acid sequence identity with BVQ, another pomovirus (GenBank Accession No. AJ 223596 formerly known as serotype Wierthe of BSBV (2). In 2005, mRT-PCR was used on samples collected from two fields of the Wielkopolska Region. Of 15 tested sugar beet plants, 12 gave positive reactions with primers specific for BSBV and nine with primers specific to BNYVV. To our knowledge, this is first report of BSBV in Poland. In Europe, BSBV was previously reported in England, the Netherlands, Belgium, Sweden, Germany, France, and Finland (2,3). References: (1) M. Jezewska and J. Piszczek. Phytopathol. Polonica, 21:165, 2001. (2) A. Maunier et al. Appl. Environ. Microbiol. 69:2356, 2003. (3) C. M. Rush and G. B. Heidel. Plant Dis. 79:868, 1995.