Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2006
Publication Date: 1/14/2007
Citation: Reddy, L., Friesen, T.L., Meinhardt, S.W., Chao, S., Faris, J.D. 2007. Genomic analysis of the Snn1 locus on the short arm of chromosome 1B in wheat. Plant and Animal Genome VX Conference Abstracts. p. 176.
Technical Abstract: SnTox1 is a host-selective proteinaceous toxin produced by the wheat pathogen Stagonospora nodorum, and it is known to play a major role in causing disease. Sensitivity to SnTox1 is governed by a single dominant gene designated Snn1, which maps within a major gene rich region on the short arm of chromosome 1B. We conducted saturation mapping of the Snn1 region using SSRs, RFLPs, and over 50 ESTs that map within deletion bin 1BSsat18-0.50-1.00. Flanking markers were used to initiate fine-mapping in a population of more than 8,000 gametes. The Langdon durum BAC library was used to construct a physical contig spanning about 500 kb at the Snn1 locus. Comparisons between the physical and genetic distances indicate that recombination frequencies are highly variable within the region harboring Snn1. Sequencing and annotation of the BAC contig revealed that genes are not randomly distributed, but a number of the predicted genes are strong candidates for Snn1. The isolation of Snn1 will allow us to begin the characterization of the interactions associated with the wheat-Stagonospora nodorum pathosystem.