Beet necrotic yellow vein virus (BNYVV) is the type member of the genus Benyvirus and the causal agent of rhizomania disease of sugar beet. Since 1999, BNYVV is becoming one of the most important viruses of sugar beet in Poland. BNYVV is represented by three types, frequently A and B and rarely P, however, in Poland, type A only was recorded (2). In 2005, a survey was conducted to determine the incidence of types A and B of BNYVV in Poland. Thirty samples of sugar beet plants with rhizomania-like symptoms were collected from six fields in the western, southern, and northern areas of Poland. All samples were analyzed by double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) with commercial antiserum (Bio-Rad, Hercules, CA). Infection of BNYVV was found in 26 samples. The presence of the virus in these samples was confirmed by reverse transcription-polymerase chain reaction (RT-PCR). The total RNA extracted from sugar beet was tested with specific primers designed to amplify a fragment of the RNA2 for BNYVV (1). Multiplex (m) RT-PCR with two sets of primers, rhizo AF/rhizo AR and rhizo BF/rhizo BR (2), was used to distinguish A and B types of BNYVV. Two obtained mRT-PCR products were sequenced and compared with other sequences available in GenBank. A 121-nt amplicon sequence (GenBank Accession No. DQ 228872) had 100% nucleotide and amino acid sequence identity with all BNYVV type B sequences (e.g., Stourton-GenBank Accession No. AY682695) (2). A 171-nt amplicon sequence (GenBank Accession No. DQ228871) had 100% nucleotide and amino acid sequence identity with all BNYVV type A sequences (e.g., Ravenna-GenBank Accession No. AY 654282) (2). Type A was detected in 23 BNYVV-infected sugar beet plants from five fields located in western and southern Poland while type B was found in three samples from one field in northern Poland. To my knowledge, this is the first report of the natural occurrence of BNYVV type B in Poland.
References: (1) A. Maunier et al. Appl. Environ. Microbiol. 69:2356, 2003. (2) C. Ratti et al. J. Virol. Methods 124:41, 2005.
