Survey of Hazelnut Cultivars for Response to Eastern Filbert Blight Inoculation

Abstract

Ninety hazelnut ( Corylus sp.) genotypes were surveyed for response to the eastern filbert blight pathogen [ Anisogramma anomala (Peck) E. Müller] following greenhouse inoculation using a combination of enzyme-linked immunosorbent assay (ELISA) and visual inspection for cankers. Most were cultivars of the European hazelnut ( Corylus avellana L.) and a few were interspecific hybrids. Six genotypes did not display signs of the pathogen or symptoms of disease: `Closca Molla', `Ratoli', `Yoder #5', `Potomac', `Medium Long', and `Grand Traverse'. `Closca Molla' and `Ratoli', both minor Spanish cultivars, are superior in many respects to `Gasaway', which has been extensively used as a completely resistant parent in breeding. `Potomac' and `Yoder #5' have C. americana Marsh. in their pedigrees, `Grand Traverse' is one-quarter C. colurna , and the origin of `Medium Long' is uncertain. The random amplified polymorphic DNA (RAPD) marker generated by primer UBC 152, which is linked to the single dominant resistance gene of `Gasaway', is absent in these six genotypes, and thus they appear to be novel sources of genetic resistance to this devastating disease.