Plant & Animal Genomes XV Conference

January 13-17, 2007
Town & Country Convention Center
San Diego, CA

DArT Marker-Based Linkage Analysis And Inheritance Of Multiple Disease Resistance In A Wild X Cultivated Barley Population

Ben P. Alsop¹ , Andrzej Kilian^2,3 , Jason Carling^2,3 , Richard A. Pickering⁴ , Brian J. Steffenson¹

¹  Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108, USA

²  Triticarte P/L, PO Box 7141, Yarralumla, Canberra, ACT 2600, Australia

³  DArT P/L, P.O. Box 7141, Yarralumla, Canberra, ACT 2600, Australia

⁴  New Zealand Institute for Crop and Food Research Limited, Private Bag 4704, Christchurch, New Zealand

The overall lack of genetic diversity in cultivated barley (Hordeum vulgare subsp. vulgare) is a limiting factor for crop improvement, especially with regard to disease resistance. Wild barley (H. v. subsp. spontaneum) is a rich source of diverse resistance alleles and can be easily hybridized with cultivated barley. To incorporate novel alleles into cultivated barley, we crossed a wild barley accession possessing multiple disease resistance (Damon) with a malting cultivar (Harrington) and constructed a Diversity Arrays Technology (DArT) marker-based linkage map for qualitative/quantitative trait analysis of disease resistance loci. Over 600 DArT markers were mapped spanning ∼2000 cM over all seven chromosomes in the Damon/Harrington double haploid population. The population was assessed at the seedling stage for reaction to five diseases: spot blotch (SB), net blotch (NB), Septoria speckled leaf blotch (SSLB), powdery mildew (PM), and stem rust (SR). In total, 15 loci for resistance were identified, four of which were positioned to regions of the genome where no resistance loci were previously reported. Many of the loci contributed by the wild parent mapped to loci previously reported to contain major genes for disease resistance, such as the mla locus for PM, Rpg4/Rpg5 for SR, Rcs5 for SB, and Rsp2/Rsp3 for SSLB. This study confirms that genes for disease resistance are clustered in the genome, regardless of whether the source is cultivated or wild barley. This implies that selective genomic sequencing in resistance gene-rich regions would be an efficient means for elucidating the majority of existing diversity for disease resistance in barley.