Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 12/11/1996
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Powdery mildew of barley is an ideal system for investigating the mechanisms of gene-for-gene interaction between large-genome cereals and obligate fungal pathogens. Barley contains a large number of genes, designated Ml, that confer resistance to powdery mildew fungus, Erysiphe graminis f. sp. hordei. The Mla resistance gene cluster is flanked by RFLP Pmarkers XciwS10 and Xbcd249.1. on chromosome 5(1H0. We have used AFLP and RAPD in conjunction with bulk segregant analysis to identify additional markers and saturate the XciwS10-Xbcd249.1 interval. Bulks that were homogeneous for DNA carrying the Mla6- or the Mla13-alleles were established from our high resolution recombinant population. Seven-hundred thirty-nine RAPD primers and 96 33P-labeled-EcoRI/MseI AFLP primer pairs were used to amplify fragments from the contrasting pools. Among approximately 8500 AFLP- and 5000 RAPD-DNA fragments, 67 AFLP polymorphisms sand 79 RAPD polymorphiams were identified. Seven AFLP markers and three RAPD markers were shown to be closely-linked to the Mla cluster. Two markers were 0.09 and 0.15 cM from the Mla locus. Their respective amplified fragments were cloned and sequenced to develop specific mapping primers for use in barley YAC library screening. Two YACs of approximately 700- and 370-kb were identified in the first screen. We are determining if these YAC clones span the Mla resistance gene cluster.