Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2003
Publication Date: January 10, 2004
Citation: Webb, C., Fellers, J.P. 2004. Physical mapping of defense related genes of wheat. Plant and Animal Genome Abstracts. Technical Abstract: The isolation of novel disease resistance genes from wheat has been a slow and laborious process, partly due to the large size and highly repetitive nature of the wheat genome. Only a handful of agronomically important wheat genes have been cloned and characterized to date. Defense related genes such as pathogen response (PR), protein kinases (PK), and resistance gene analogs (RGAs), specifically of the NBS-LRR class, have proven important tools in the identification and isolation of functional resistance genes from a number of other important plant species. For this reason, bin mapping disease resistance-associated markers needs to continue so as to enhance map-based cloning and candidate gene analysis efforts. We have placed 51 defense-related markers, derived from a variety of resistance sources, onto the genetic map of wheat. These markers represent expressed sequence tag (EST) clones isolated from a pooled Thatcher isoline library, resistance gene like ESTs cloned from an Aegilops tauschii library, ESTs from two scab-resistant libraries, and markers resulting from random PCR amplification of wheat cDNA pools. Forty-one of the 51 markers were polymorphic on 78 EcoRI-restricted Chinese Spring deletion lines, 23 ditelosomic stocks and 21 nullisomic wheat lines. Seven of the markers displayed a monomorphic hybridization fragment pattern and three could not be scored. Here we report the bin map locations of these defense-related markers and discuss their proximity to known disease resistance genes in wheat.