First report of Wheat dwarf virus and its vector (Psammotettix provincialis) affecting wheat and barley crops in Syria.
A field survey covering the major cereal-production areas of Syria was conducted during May 2009. A total of 938 wheat and 971 barley samples with typical symptoms of viral infection were collected from 45 wheat and 58 barley fields. Serological tests showed that Wheat dwarf virus (WDV) was detected in 16 wheat (cv. Cham 8) and 5 barley (cv. Arabic abiad) samples collected from Al-Hasskah governorate (eastern region of Syria) and showing dwarfing, yellowing, and reduced heading. The identity of WDV was confirmed by PCR assay. Leafhopper transmission tests indicated that only Psammotettix provincialis was able to transmit Syrian barley WDW isolates from infected barley plants to healthy barley (48 plants became infected of 50 plants inoculated) and oats (45 of 50) under greenhouse conditions. WDV has been reported to infect cereals in other countries in West Asia and North Africa (Turkey, Tunisia and Morocco) and causes economic losses on wheat in many countries in Europe (e.g. Sweden). WDV has been reported to be transmitted in a persistent manner only by leafhoppers (Psammotettix alienus) to a wide range of cereal and wild grasses. Two strains of WDV are known, one that primarily infects wheat and another that infects barley. This is thought to be the first report of WDV (both strains) infecting wheat and barley crops in Syria and the first report of P. provincialis as a WDV vector worldwide.