FINE MAPPING OF EASTERN FILBERT BLIGHT RESISTANCE IN HAZELNUT WITH SCAR AND SSCP MARKERS DEVELOPED FROM BAC END SEQUENCES

Abstract

Eastern filbert blight (EFB), caused by the pyrenomycete Anisogramma anomala is a devastating disease of European hazelnut (Corylus avellana) in the Pacific Northwest where it is a serious threat to the industry's existence. A dominant allele at a single locus from the obsolete pollenizer 'Gasaway' confers complete resistance, for which several linked RAPD (random amplified polymorphic DNA) markers have been identified. Seedlings in our mapping population were scored for flanking RAPD markers UBC152 800 and UBC268 580 . Twenty-two primer primers were designed from the DNA sequences of 11 RAPD markers and used as sequence characterized amplified region (SCAR) markers for PCR screening of a BAC library for 'Jefferson', which is heterozygous for resistance. We developed new SCAR and SSCP (single stranded confirmation polymorphism) markers from 36 BAC end sequences and constructed a fine map of the resistance region. The map spans 3.7 cM and has an average interval of 0.3 cM between markers. The new markers are being used in map-based cloning of the 'Gasaway' resistance allele, and may be useful for marker-assisted selection.