1. Presence of Wheat dwarf virus, Cereal yellow dwarf virus-RPV and Barley yellow dwarf viruses in cereal species in Martonvásár Dalma PRIBÉK 1 – Emil POCSAI 2 – Gyula VIDA 1 – Ottó VEISZ 1 1 Agricultural Research Institute of the Hungarian Academy of Sciences, Martonvásár, Hungary 2 Plant Protection and Soil Conservation, Fejér County Service, Velence, Hungary

2. Protection against viruses Agronomical measures Insecticides and herbicides against vectors and weeds Resistant and tolerant varieties

3. Damage and incidence rate of the viruses vary with The most widespread viruses in the central part of Hungary Wheat dwarf virus (WDV) Cereal yellow dwarf virus-RPV (CYDV-RPV) Barley yellow dwarf virus-MAV (BYDV-MAV) Barley yellow dwarf virus-PAV (BYDV-PAV) RMV virus (RMV) SGV virus (SGV) YearLocationCrop

4. During the acquisition feeding period, virions enter the posterior mid-gut, and then pass to the haemolymph, and from there to the accessory salivary gland, and back to the stylet. THE INCUBATION PERIOD A considerable time (10-20 days) elapses between the acquisition feeding period and the appearance of virions in the stylet. Starvation and moulting do not influence the vector ability. Infectious ability remains for a long time, often indefinitely. Persistant transmission

5. The first incidence of cereal viruses abroad and in Hungary BYDV 1951Oswald  Houston California 1966 Szirmai Hungary WDV 1961 Vacke Czechoslovakia 1988 Gáborjányi et al. Hungary

6. Natural Host Range Barley ( Hordeum vulgare L.) Rye ( Secale cereale L.) Oat ( Avena sativa L.) Triticale ( Triticosecale X ) Wheat ( Triticum aestivum L.) Etc. Symptoms: - yellowing - stunting - the root development is poor - tillering is intense - some of the plants die before heading or harvesting

7. Aims: estimate the incidence ratios of the viruses on cereals grown in Martonvásár compare the results of the 2005 virological survey with data for the past four years

8. Tested species Winter wheat ( Triticum aestivum L. ) Winter barley ( Hordeum vulgare L. ) Durum wheat ( Triticum durum Desf. ) Winter oat (Avena sativa L.) Triticale ( Triticosecale X ) Collection Leaves of cereals exhibiting virus symptoms Each year 50-50 samples from each species (exception of 2004 – these data were omitted from the evaluation) Detection ELISA (Enzyme-linked Immunosorbent Assay ) Data evaluation two-factor analysis of variance

9. Incidence of cereal viruses as a percentage of virus-infected plants

10. Effect of viruses and years, as revealed by analysis of variance (2001–2005) *** = Significant at the P=0.1% level n.s. = Non-significant

11. Effect of viruses and host plants, as revealed by analysis of variance (2001–2005) *** *** = Significant at the P=0.1% level

12. Percentage distribution of the varieties between 2001 and 2005, averaged over all the plants Sváb (1981)

13. Conclusions: In all four (2001, 2002, 2003, 2005) years WDV, which is transmitted by leafhoppers, was present in the highest ratio on all the plant species. The data for 2001, 2002, 2003 and 2005 exhibited a clear pattern, except 2004 when the number of virus infected plants was extremely low. In many cases the same host plant was infected simultaneously by several viruses. The aphids that transmit the RMV, SGV, BYDV- MAV, BYDV-PAV and CYDV-RPV viruses were far less active. No significant differences were found within these viruses.

14. These data confirm the results of earlier surveys suggesting that WDV infection was far more serious than other virus infection in the central part of Hungary. Thank You For Your Attention!