'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 CO-LOCALISATION OF (QUANTITATIVE) RESISTANCE GENES AGAINST LEAF-RUST AND POWDERY MILDEW AND RESISTANCE-GENE-ANALOGS (RGAS) IN BARLEY G. BACKES, L. MADSEN, J.S. JENSEN, A. JAHOOR Risø National Laboratory, P.O. Box 49, DK-4000 Roskilde, Denmark

Quantitative resistance genes (QRGs) for resistance against powdery mildew and leaf rust were localised in a segregating population (121 RI lines) from a cross between the barley variety ‘Vada’ and the wild barley line ‘1B-87’, origination from Israel. The linkage map included 13 RGA (resistance gene analog) loci. Resistance against powdery mildew and leaf rust was scored in a field. Additionally, powdery mildew resistance was tested on detached leaves. The resistance data revealed quantitative distribution for all observation data. QRGs with strong effects were found for any of the observations and showed additivity. Three of the seven QRGs co-localised with RGA-loci.