NEW SOURCES OF RESISTANCE TO EASTERN FILBERT BLIGHT AND LINKED MARKERS

The hundred-year history of the hazelnut industry in the Pacific Northwest (USA) is threatened by eastern filbert blight caused by the fungus Anisogramma anomala (Peck) E. Müller.
Marker-assisted selection has been extensively used for ‘Gasaway’ resistance in the hazelnut breeding program at Oregon State University, USA. Concern over the possible breakdown of this single dominant resistance gene provides an incentive to look for new sources of resistance.
Three genotypes (OSU 408.040 from Minnesota, ‘Ratoli’ from Spain and OSU 759.010 from the Republic of Georgia) have shown no signs or symptoms of the disease following a series of greenhouse inoculations or exposure of potted trees under structures topped with diseased wood.
All three resistance sources were crossed with susceptible selections, and segregation ratios in the progeny indicate simple inheritance.
PCR-based DNA markers linked to resistance have been identified for all three sources and will be useful for marker-assisted selection.
More than 100 simple sequence repeat (SSR) loci have been developed and assigned to linkage groups.
Co-segregation of disease response and SSR alleles allowed us to assign the resistance loci to linkage groups.
Resistance from ‘Gasaway’ and the three new sources are independent, as the loci map to four different linkage groups.
These new sources of resistance will be used in hazelnut breeding either singly or through pyramiding of resistance genes, for which the identified markers will play a prominent role in marker-assisted selection.

VII International Congress on Hazelnut

V. Sathuvalli, S.A. Mehlenbacher, D.C. Smith

Corylus, hazelnut, disease resistance, Anisogramma anomala, RAPD markers

https://doi.org/10.17660/ActaHortic.2009.845.13