Seed-borne pathogens detected in consignments of cereal seeds received by the International Center for Agricultural Research in the Dry Areas (ICARDA), Syria

During 1995-2004, the Seed Health Laboratory at the International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria, tested all incoming cereal seed from 41 countries (251 seed lots comprising 91,993 samples) for the presence of seed-borne pathogens. Pest detection methods used included direct visual inspection, wash-filter, freezing-blotter, embryo, seed-gall nematode and growing-on tests. Analysis of seed lots with 30 seeds (53,566 seeds in total) revealed that 22.03% (11,797) of the seeds, predominantly of barley and wheat, were infected. Of these, 20.02% were infected with Tilletia caries and/or T. foetida, followed by T. controversa (0.99%), Ustilago tritici (0.30%), T. indica (0.27%), Fusarium spp. (0.25%), Helminthosporium spp. (0.09%), Ustilago spp. (0.03%), Urocystis agropyri (0.02%), Anguina tritici (0.02%) and Ustilago hordei (0.01%). The frequency of Tilletia indica-infection in seed samples was: Ethiopia 13.31%, Azerbaijan 10.20%, Tajikistan 0.64%, and Turkey 0.22%. T. indica and T. controversa do not occur in Syria and are considered as quarantine pests with zero tolerance. The implications of these findings for the safe movement of cereal germplasm are discussed.