'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 LOCALIZATION OF A NEW POWDERY MILDEW RESISTANCE GENE USING AFLP AND MICROSATELLITE MARKERS M.R. NAGHAVI, A. JAHOOR Agronomy and breeding Dept., Tehran University, Karaj, Iran

A new major, race specific, resistance gene to powdery mildew (Erysiphe graminis f. sp. hordei) was identified in barley line 132-45*Sonja, using fluorescence-based AFLP and microsatellite techniques. A total of 80 AFLP and 63 microsatellite combinations of primers were screened for polymorphism by use of Bulked Segregant Analysis (BSA). Five AFLP markers E36-M49 (230), E32-M49 (250), E36-M48 (103), E41-M48 (82) and E40-M48 (279), and Two microsatellite markers Ebmac0222 and Ebmac0824, were identified that linked to resistance locus. Our results indicated this new gene that designate as Mln, is located on the long arm of chromosome 7(5H) and flanked by microsatellite marker Ebmac0222, at distance of 5 centimorgans (cM). Closely linked AFLP and microsatellite markers are potentially useful in marker-assisted breeding to improve resistance to powdery mildew in barley.