Investigating host‐pathogen interactions for the wheat leaf blotch pathogen Parastagonospora nodorum Leaf blotch caused by Parastagonospora nodorum is a severe disease on wheat in Norway leading to grain shriveling and reduced yield, and is a main cause of fungicide application. It has recently been discovered that leaf blotch pathogens secrete necrotrophic effectors (NE) that are recognized by sensitivity loci in the host to trigger programmed cell death. This is the opposite situation of the “classical” gene‐for‐gene hypothesis, where the effector recognition by the plant leads to resistance. Necrotrophic pathogens like P. nodorum take advantage of this defense response in order to grow on the dead plant tissue. SF sf NE Susceptible Resistant ne Resistant Resistant “Inverse” gene‐for‐gene interaction between dominant NE and dominant SF will result in a susceptible reaction. We use a combination of classical inoculation and infiltration experiments in the field and in the greenhouse and next‐generation sequencing and bioinformatics such as QTL mapping to explore the molecular mechanisms that are decisive for resistance or susceptibility. Possible research topics for master students include: 
Identification of main genetic loci for leaf blotch resistance and NE sensitivity in various wheat mapping populations that have been genotyped with high‐density SNP markers. The MSc thesis project might include testing of selected materials in field trials, greenhouse inoculations with single isolates and infiltration of seedlings with culture filtrates and purified effectors from P. nodorum. Based on these data, the student will conduct QTL mapping and identify the underlying genetic loci. 
Validation of molecular markers for breeding. We have through previous studies identified important QTL for leaf blotch resistance and a potentially novel NE sensitivity locus that need further validation before implementation in breeding. This will include testing the effect of these loci in new mapping populations, purification of effectors from pathogen isolates and infiltration and inoculation experiments. 
Characterization of the Norwegian pathogen population of P. nodorum, based on a recently established collection of 200 pathogen isolates from Norwegian wheat fields. This thesis work might include genotyping and/or sequencing of the isolates to conduct a population genetic study, investigate the presence of known effector genes, screening for fungicide sensitivity and bioinformatics analyses. Various combinations of the above topics are also possible, depending on the interests of the student. Please contact us for the further information: Morten Lillemo (researcher) Andrea Ficke (researcher; NIBIO) Min Lin (PhD student) [email protected] [email protected] [email protected]