|Gobelman Werner, Karin|
Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/18/1998
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Powdery mildew of barley is a model system for the investigation into the mechanisms of gene-for-gene interaction between large-genome cereals and obligate fungal pathogens. Barley contains a large number of genes, designated <i>Ml, that confer resistance to the powdery mildew fungus, <i>Erysiphe graminis f. sp.<i>hordei. One particular group, the <i>Mla resistance gene cluster, is located on chromosome 5(1H) and is flanked by RFLP markers <i>XciwS10 and <i>Xbcd249.1. We have used AFLP and RAPD technology in conjunction with bulk segregant analysis to identify additional markers and saturate the <i>XciwS10-Xbcd249.1 interval. We identified 7 AFLP and 2 RAPD polymorphisms that were closely linked to the <i>Mla cluster. Two were determined as being 0.09 and 0.12 cM from <i>Mla. Their respective amplified fragments were used to develop allele-specific primers and a total of eleven YACs were identified from screening two independent YAC libraries. A physical contig map of the region spanned by these clones was generated and efforts are underway to determine if this region extends across the <i>Mla locus. Sub-genomic-PCR has been employed to further characterize the YACs with regard to resistance gene analogues (RGAs). This technique was used in conjunction with primers designed from previously isolated resistance genes to selectively amplify homologous sequences from the <i>Mla region contained within selected YACs. This increases the specificity of amplification of RGAs and leads to the possibility of cloning the <i>Mla gene by this PCR strategy.