Powdery mildew (Blumeria graminis f.sp. hordei) is currently one of the most serious disease of barley in Australia. Especially in WA, growers have reported increasingly severe and epidemic levels of disease. These epidemics are due to the failure of both genetic and chemical control methods. Extensive planting of susceptible varieties led growers to place undue reliance on a limited range of demethylation-inhibiting (DMI) fungicides. These act on the Cyp51 gene and strong selection pressure has led to new and widespread Cyp51 DMI resistance mutations in WA.
Traditionally, breeders have selected major resistance genes (R-genes) to control powdery mildew. These are also known as dominant race-specific resistance genes, and follow a pathogen race avirulence gene/host cultivar R-gene relationship. Extensive field experience has shown such resistance is seldom durable as avirulence genes can readily mutate, especially when used on a large scale.
Experience suggests the best ways of achieving durable resistance is to use either mlo or genes conferring broad resistance. This project aims to provide barley breeders with the knowledge and tools to deliver stably resistant barley cultivars.
We conduct multi-disciplinary research into powdery mildew disease using broad range of techniques. These cover pathotype monitoring, avirulence gene evolution and prevalence, detection of new resistance genes, resistance gene identification, cytology, bioinformatics and genetic mapping.