Response of Hazelnut Accessions to Greenhouse Inoculation with Anisogramma anomala.

Eastern filbert blight (EFB), caused by the pyrenomycete Anisogramma anomala (Peck) E. Müller, is a devastating disease of European hazelnut (Corylus avellana L.) in the Pacific Northwest. Host genetic resistance from 'Gasaway' has been used extensively for breeding hazelnuts at Oregon State University. Concern over the durability of this single-gene resistance prompted a search for new sources of resistance. In this study, 86 accessions from 11 countries were evaluated for their response to greenhouse inoculation with the pathogen. Nine accessions showed complete resistance, including one from Chile ('Amarillo Tardio'), two from Serbia ('Crvenje' and 'Uebov'), one from southern Russia (OSU 495.072) and five from Moscow, Russia. These new sources of EFB resistance have geographically diverse origins and will broaden the genetic base of EFB-resistant hazelnut germplasm. The previously reported resistance of 'Grand Traverse' from Michigan and the susceptibility of 'Closca Molla' from Spain were confirmed. [ABSTRACT FROM AUTHOR]