First Report of Onion yellow dwarf virus, Garlic common latent virus and Shallot latent virus on Garlic in Poland.

Abstract

Garlic (Allium sativum L.) is vegetatively propagated and can be affected by a virus complex (1) consisting of two potyviruses, Onion yellow dwarf virus (OYDV) and Leek yellow stripe virus (LYSV), and two carlaviruses, Garlic common latent virus (GCLV) and Shallot latent virus (SLV) (2). OYDV, GCLV, and SLV are economically important viral pathogens of bulb garlic crops in many garlic-growing areas of the world. A general mosaic and yellowing of leaves of four garlic cultivars (Blanko, Harnaś, Jarus, and Mega) was observed in 11 garlic-production fields in the Lodz, Mazowieckie, Małopolska, and Pomorskie regions of Poland in July 2012. ELISA was carried out with extracts from 29 collected garlic leaf samples to detect OYDV, GCLV, and SLV using commercial antiserum (DSMZ, Braunschweig, Germany). Results indicated that 6 samples (20.7%) were infected with OYDV, 25 samples (86.2%) were infected with GCLV, and 23 samples (79.3%) were infected with SLV. The presence of these viruses in garlic leaf samples was confirmed by reverse transcription (RT)-PCR using total RNA extracted using the Spectrum Plant Total RNA kit (Sigma-Aldrich, Munich, Germany) and primers, designed in this study, specific to the whole coat protein gene of OYDV (OYDVF 5'-TAGGGTTGGATTATGATTTCTCGA-3' and OYDVR 5'-TAGTGGTACACCACATTTCGT-3'), GCLV (GCLVF 5'-TTATAGGGACGGCACAAAATCAATCA-3' and GCLVR 5'-AATAGCACTCCTAGAACAACCATT-3') and SLV (SLVF 5'-AATYATTTACAATCGTCCAGCTA-3' and SLVR 5'-ATAATATCAATCAAATMCACACAATT-3'). Amplicons of the expected size were obtained for each virus. The amplified products were purified and sequenced in both directions. Sequence information of the CP genes of 9 OYDV, 12 GCLV, and 7 SLV isolates has been submitted to NCBI-GenBank with accession numbers KF862683 to KF862710. Sequence analysis showed that the coat protein gene of OYDV shared 86% identity with the coat protein gene of OYDV isolate MS/SW1 from Australia (GenBank Accession No. HQ258894). Comparison of the coat protein gene sequences of Polish GCLV isolates with those available in GenBank showed 85 to 91% sequence identities. Multiple sequence alignment revealed 84% nucleotide identity between the Polish isolate of SLV and an SLV isolate from Chinese garlic (AF314147) formerly referred to as Garlic latent virus (3). To the best of our knowledge, this is the first report of OYDV, GCLV, and SLV in garlic plants in Poland. The accurate identification of viruses present in garlic plants will help to use the appropriate strategies to reduce viral incidence in garlic-growing areas.