My PhD thesis was entitled Recent evolution of Rhynchosporium secalis populations in response to selection by triazoles. The project was based at Rothamsted Research in the Fungicide Resistance Group, and the PhD degree awarded by the University of Reading School of Biological Sciences. This was supported by a CASE studentship funded by the BBSRC (UK Biotechnology and Biological Sciences Research Council) and Syngenta Crop Protection.
Rhynchosporium commune (previously included within Rhynchosporium secalis s.l.) is a major foliar pathogen of barley worldwide, especially in wet temperate regions including the UK. Only partially resistant barley varieties are available, so effective control requires fungicides too. However, fungicide use may select for resistance. Resistance to the MBC fungicides spread in R. commune in the early 2000s, followed by some reports of decreased sensitivity to some azoles and, most recently, isolated cases of QoI resistance. This project assessed sensitivity to triazole and QoI fungicides in R. commune and investigated the molecular mechanisms responsible for altered sensitivity, including mutations and altered gene expression. I was also able to track the historical emergence of azole resistance, by using molecular diagnostics with archived long-term experimenal samples. The main findings are published here.