Barley yellow dwarf disease, a ubiquitous virus disease of cereal crops worldwide, is caused by a group of related, single-stranded RNA viruses assigned to Luteovirus (Barley yellow dwarf virus [BYDV] spp. PAV, PAS, MAV, and GAV) or Polerovirus (Cereal yellow dwarf virus-RPV) genera or unassigned to a genera (BYDV-SGV, BYDV-RMV, and BYDV-GPV) in the family Luteoviridae (1). Incidence of BYDV in cereal crops (e.g., barley, wheat, and oats) was high, and in recent years, reached epidemic levels in many regions of the Czech Republic. BYDV-PAV and BYDV-PAS have been identified in Czech cereal crops (2,4). Surveys of the incidence of BYDV were carried out using ELISA (SEDIAG SAS, Longvic, France) and one-step reverse transcription (RT)-PCR (Qiagen, Hilden, Germany) (2) during 2007 and 2008. Samples (125) were collected from different fields around the Czech Republic and 96 were BYDV positive. Three of the field isolates, CZ-6815, CZ-1561, and CZ-10844, from oat (Avena sativa; cv. Auron), winter wheat (Triticum aestivum; cv. Apache), and winter barley (Hordeum vulgare; cv. Merlot), respectively, were identified as BYDV-MAV by sequencing of the RT-PCR product (641-bp fragment) used to identify BYDV, which spanned 2839--3479 of the BYDV genome (GenBank Accession Nos. EF043235 and NC_002160) (2). The partial coat protein gene sequence of 483 nt was compared with the available sequences of 12 BYDV-PAV isolates (PAV-JP, PAV-NY, PAV-ILL, PAV-AUS, PAV-WG2, PAV-whG4y3, PAV-on21-4, Tahoe1, CA-PAV, HB3, FH3, and MA9501); nine BYDV-PAS isolates (PAS-129, PAS-64, WS6603, WG13, PAS-Tcb4-1, PASwaw5-9, FL2, PAS-Vd29, and PAS-MA9516); and six BYDV-MAV isolates (MAV-CA, MAV-PS1X1, MAV-Alameds268, LMB2a, SI-o4, and MAV-CN) by MEGA4 (3). Nucleotide and amino acid sequence identities for the three isolates ranged from 92.9 to 99.4% and 88.0 to 95.8%, respectively, for available BYDV-MAV isolates; 76.8 to 78.2% and 62.7 to 67.6%, respectively, for available BYDV-PAS isolates; and 77.6 to 79.3% and 65.5 to 70.4%, respectively, for available PAV isolates. The sequence data indicates that these isolates (CZ-6815, CZ-1561, and CZ10844; GenBank Accession Nos. FJ645747, FJ645758, and FJ645746, respectively) are BYDV-MAV. To my knowledge, this is the first record of BYDV-MAV in the Czech Republic.
References: (1) C. J. D'Arcy and L. L. Domier. Page 891 in: Virus Taxonomy-8th Report of the ICTV. C. M. Fauquet et al., eds. Springer-Verlag, NY, 2005. (2) J. K. Kundu. Plant Dis. 92:1587, 2008. (3) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007. (4) J. Vacke. Page 100 in: Sbornik Referatu z Odborneho Seminare, Aktualni Problemy Ochrany Polnich Plodin, Praha, 1991.
