The complete genome for a barley isolate of Wheat dwarf virus (WDV) from Tekirdağ, Turkey, WDV-Bar[TR], was isolated and sequenced. The genome was found to be 2739 nucleotides long, which is shorter than wheat-infecting WDV isolates, and with a genome organization typical for mastreviruses. The complete genome of WDV-Bar[TR] showed 83-84% nucleotide identity to wheat isolates of WDV, with the non-coding regions SIR and LIR least conserved (72-74% identity). The deduced amino acid sequences for Rep and RepA were most conserved (92-93%), while CP and MP were less conserved (87% and 79-80%, respectively). The identity to other mastrevirus species was significantly lower. In phylogenetic analyses, the WDV isolates formed a distinct clade, well separated from the other mastreviruses with the wheat isolates grouping closely together. Phylogenetic analyses of WDV-Bar[TR], the partial sequence for another Turkish barley isolate (WDV-Bar[TR2]) and published WDV sequences further supported the division of WDV into two distinct strains. The barley strain could also be divided into three subtypes based on relationships and geographic origin. This study shows the first complete published sequence for a barley isolate of WDV.

A survey for the detection of cucumber mosaic virus (CMV), papaya ringspot virus-W (PRSV-W), squash mosaic virus (SqMV), melon necrotic spot virus (MNSV), cucumber green mottle mosaic virus (CGMMV), zucchini yellow mosaic virus (ZYMV) and watermelon mosaic virus-2 (WMV-2) was carried out in June and July 2005, covering 17 melon fields and 19 watermelon fields in the Tekirdag, Edirne and Kırklareli provinces of Turkish Thrace. Among all the fields sampled, only one melon field was not virus-infected. In all, 502 melon and watermelon samples were tested for the presence of seven viruses with ELISA tests using polyclonal antisera. Overall, 333 out of 502 samples tested positive for the investigated viruses: 167 out of 235 plant samples in Tekirdag, 103 out of 187 samples in Edirne, and 63 out of 80 samples in Kırklareli were positive. Serological tests showed that six out of the seven tested viruses were present in the Thrace region of Turkey. The following rates of incidence of tested viruses on watermelon were found: ZYMV (45.5%), WMV-2 (34.2%), CMV (19.9%), PRSV-W (2.1%), SqMV (1.8%) and MNSV (0.4%), while the rates of incidence on melon were ZYMV (40.3%), WMV-2 (31.2%), CMV (7.2%), PRSV-W (2.3%), SqMV (0.5%) and MNSV (1.8%). The WMV-2+ZYMV mixed infection type was the most widespread both on melon and on watermelon samples at 16.7% and 11.4%, respectively.

AbstractA survey for detection of barley yellow dwarf luteoviruses (BYDV-PAV and BYDV-MAV), cereal yellow dwarf polerovirus (CYDV-RPV), barley stripe mosaic hordeivirus (BSMV), wheat dwarf monogeminivirus (WDV) and brom mosaic bromovirus (BMV) was carried out during May 2003 covering seven cereal-growing counties of Tekirdag, Turkey. Two hundred sixty (260) wheat samples with yellowing, stunting, or striping were collected from 26 wheat fields. These samples were tested for the presence of six viruses by ELISA using polyclonal antisera. Serological tests showed that six tested viruses were present in Tekirdag, Turkey. Among the tested viruses, BYDV-MAV was the most commonly detected (25% of the 260 wheat samples), followed by BYDV-PAV (22.3%), WDV (16.5%), CYDV-RPV (8.5%), BMV (3.1%) and BSMV (1.5%). This study revealed the presence of six viruses in wheat fields in Tekirdag and reported for the first time BSMV and BMV on wheat in Turkey.

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