Exploration of Niab synthetic wheat as a new source of resistance for effective genetic control of Septoria tritici blotch disease

Septoria tritici blotch (STB) is currently the most economically damaging fungal disease of wheat in the UK. Growers remain heavily reliant on fungicides, as most commercial wheat varieties offer only moderate levels of resistance. However, these chemical protections are increasingly threatened by evolving fungicide resistance in the pathogen and tightening legislative restrictions. Therefore, identifying more effective, genetically based resistance is a pressing priority for sustainable wheat production. Access to wheat varieties with natural resistance to STB would reduce fungicide use, offering both agronomic and environmental benefits. Wild relatives of wheat, such as goat grass (Aegilops spp.), are a valuable source of genetic resistance to multiple diseases. By crossing tetraploid pasta wheat with diverse goat grass accessions, Niab has developed synthetic hexaploid wheat (SHW) lines and corresponding genetic mapping populations. These materials represent a promising, yet underexplored, resource for improving STB resistance in modern wheat. The main aim of this project is to investigate whether these SHWs carry novel genes associated with STB resistance. Primary SHWs will be screened under growth room conditions using controlled fungal inoculations. Based on these results, a subset of promising lines from the derived nested association mapping (NAM) populations will be selected and evaluated under field conditions across at least two growing seasons. Phenotyping data will then be combined with existing high-density marker datasets to genetically map loci associated with STB resistance. Finally, through controlled inoculations and microscopy, the student will explore whether identified resistance loci are growth-stage specific (i.e. effective in both seedlings and adult plants) and whether resistance mechanisms act pre- or post-stomatal penetration.