Barley-Pyrenophora graminea interaction: QTL analysis and gene mapping

Pyrenophora graminea is a seed-borne pathogen and is the causal agentof the barley leaf stripe disease. Our aim is to study the genetic basis ofbarley resistance to leaf stripe. A qualitatively acting resistance factorhas been identi_ed in the cultivar Vada and the partial resistance ofthe cultivar Proctor to a P. graminea isolate has been demonstratedto be dominated by a major quantitative trait locus (QTL) mapped onbarley chromosome 1(7H). Map colinearity between the leaf stripe Proctorresistance QTLs, Vada resistance to leaf stripe, and other diseaseresistance loci have been investigated in this work using molecularmarkers. Moreover, since inoculation of barley rootlets by the fungushad been shown to induce the accumulation of several PR (pathogen-related) mRNA families, seven barley PR genes have been mapped asRFLPs, and one assigned to a chromosome arm via ditelosomic analysisto verify possible map associations with resistance QTLs. This workdiscusses the genetic relationships between the known leaf stripe resistance loci, resistance loci towards other seed!borne pathogens anddefence gene loci.