Blumeria graminis f. sp. avenae

Abstract

Abstract Blumeria graminis f. sp. avenae (Bga) , the causal agent of powdery mildew disease on oats, is one of the most important diseases of oat production. The main control strategies include the use of fungicides and resistant cultivars. However, with the overuse of chemical controls and a dependency on a limited number of resistance genes, this pathogen is becoming more difficult to control and eradicate from the crop. To date, only 12 genes that confer resistance to Bga have been catalogued in oats, and only half of these are deployed in commercially available oat cultivars. Because of this, there is a constant need to understand the mechanisms underlying oat resistance and a demand for new durable forms of resistance. Key Concepts Bga is the causal agent of powdery mildew disease in oats and a major limiting factor to oat yield and quality. Genetic resistance is considered the most sustainable control method, to date 12 powdery mildew (Pm) resistance genes have been identified in oats. Pre‐ and post‐penetration defence mechanisms, such as papillae formation, cell death and encasements contribute to oat plant defence against Bga infection. New disease resistance may be sourced from wild oat relatives, but sterility barriers may cause breeding issues. The published oat MLO (Mildew Locus O) gene family presents a potential opportunity for generating durable mlo‐based powdery mildew resistance in oats.